lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

146 files changed, 19812 insertions, 0 deletions

diff --git a/lib/mlibc/options/posix/generic/arpa-inet-stubs.cpp b/lib/mlibc/options/posix/generic/arpa-inet-stubs.cpp
new file mode 100644
index 0000000..0bc9727
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/arpa-inet-stubs.cpp
@@ -0,0 +1,220 @@
+
+#include <arpa/inet.h>
+#include <bits/ensure.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <mlibc/bitutil.hpp>
+#include <mlibc/debug.hpp>
+
+const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
+const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
+
+uint32_t htonl(uint32_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint32_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+uint16_t htons(uint16_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint16_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+uint32_t ntohl(uint32_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint32_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+uint16_t ntohs(uint16_t x) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return mlibc::bit_util<uint16_t>::byteswap(x);
+#else
+	return x;
+#endif
+}
+
+// ----------------------------------------------------------------------------
+// IPv4 address manipulation.
+// ----------------------------------------------------------------------------
+in_addr_t inet_addr(const char *p) {
+	struct in_addr a;
+	if(!inet_aton(p, &a))
+		return -1;
+	return a.s_addr;
+}
+char *inet_ntoa(struct in_addr addr) {
+	// string: xxx.yyy.zzz.aaa
+	// 4 * 3 + 3 + 1 = 12 + 4 = 16
+	thread_local static char buffer[16];
+	uint32_t proper = htonl(addr.s_addr);
+	snprintf(buffer, sizeof(buffer), "%d.%d.%d.%d",
+		(proper >> 24) & 0xff, ((proper >> 16) & 0xff),
+		(proper >> 8) & 0xff, proper & 0xff);
+	return buffer;
+}
+int inet_aton(const char *string, struct in_addr *dest) {
+	int array[4];
+	int i = 0;
+	char *end;
+
+	for (; i < 4; i++) {
+		array[i] = strtoul(string, &end, 0);
+		if (*end && *end != '.')
+			return 0;
+		if (!*end)
+			break;
+		string = end + 1;
+	}
+
+	switch (i) {
+		case 0:
+			dest->s_addr = htonl(array[0]);
+			break;
+		case 1:
+			if (array[0] > 255 || array[1] > 0xffffff)
+				return 0;
+			dest->s_addr = htonl((array[0] << 24) | array[1]);
+			break;
+		case 2:
+			if (array[0] > 255 || array[1] > 255 ||
+					array[2] > 0xffff)
+				return 0;
+			dest->s_addr = htonl((array[0] << 24) | (array[1] << 16) |
+				array[2]);
+			break;
+		case 3:
+			if (array[0] > 255 || array[1] > 255 ||
+					array[2] > 255 || array[3] > 255)
+				return 0;
+			dest->s_addr = htonl((array[0] << 24) | (array[1] << 16) |
+				(array[2] << 8) | array[3]);
+			break;
+	}
+
+	return 1;
+}
+
+// ----------------------------------------------------------------------------
+// Generic IP address manipulation.
+// ----------------------------------------------------------------------------
+const char *inet_ntop(int af, const void *__restrict src, char *__restrict dst,
+		socklen_t size) {
+	switch (af) {
+		case AF_INET: {
+			auto source = reinterpret_cast<const struct in_addr*>(src);
+			if (snprintf(dst, size, "%d.%d.%d.%d",
+						source->s_addr & 0xff,
+						(source->s_addr & 0xffff) >> 8,
+						(source->s_addr & 0xffffff) >> 16,
+						source->s_addr >> 24) < (int)size)
+				return dst;
+			break;
+		}
+		case AF_INET6: {
+			auto source = reinterpret_cast<const struct in6_addr*>(src);
+			size_t cur_zeroes_off = 0;
+			size_t cur_zeroes_len = 0;
+			size_t max_zeroes_off = 0;
+			size_t max_zeroes_len = 0;
+
+			/* we look for the largest block of zeroed quartet(s) */
+			for(size_t i = 0; i < 8; i++) {
+				auto ptr = source->s6_addr + (i * 2);
+				if(!ptr[0] && !ptr[1]) {
+					cur_zeroes_len++;
+					if(max_zeroes_len < cur_zeroes_len) {
+						max_zeroes_len = cur_zeroes_len;
+						max_zeroes_off = cur_zeroes_off;
+					}
+				} else {
+					/* advance the offset to the next quartet to check */
+					cur_zeroes_len = 0;
+					cur_zeroes_off = i + 1;
+				}
+			}
+
+			size_t off = 0;
+			for(size_t i = 0; i < 8; i++) {
+				auto ptr = source->s6_addr + (i * 2);
+
+				/* if we are at the beginning of the largest block of zeroed quartets, place "::" */
+				if(i == max_zeroes_off && max_zeroes_len >= 2) {
+					if(off < size) {
+						dst[off++] = ':';
+					}
+					if(off < size) {
+						dst[off++] = ':';
+					}
+					i += max_zeroes_len - 1;
+
+					continue;
+				}
+
+				/* place a colon if we're not at the beginning of the string and it is not already there */
+				if(off && dst[off - 1] != ':') {
+					if(off < size) {
+						dst[off++] = ':';
+					}
+				}
+
+				off += snprintf(dst + off, size - off, "%x", ptr[0] << 8 | ptr[1]);
+			}
+
+			dst[off] = 0;
+
+			return dst;
+		}
+		default:
+			errno = EAFNOSUPPORT;
+			return NULL;
+	}
+
+	errno = ENOSPC;
+	return NULL;
+}
+int inet_pton(int af, const char *__restrict src, void *__restrict dst) {
+	switch (af) {
+		case AF_INET: {
+			uint8_t array[4] = {};
+			for (int i = 0; i < 4; i++) {
+				char *end;
+				long int value = strtol(src, &end, 10);
+				if (value > 255)
+					return 0;
+				if (*end != '\0' && *end != '.')
+					return 0;
+				src = end + 1;
+				array[i] = value;
+			}
+			auto addr = reinterpret_cast<struct in_addr*>(dst);
+			memcpy(&addr->s_addr, array, 4);
+			break;
+		}
+		case AF_INET6:
+			mlibc::infoLogger() << "inet_pton: ipv6 is not implemented!" << frg::endlog;
+			/* fallthrough */
+		default:
+			errno = EAFNOSUPPORT;
+			return -1;
+	}
+
+	return 1;
+}
+
+struct in_addr inet_makeaddr(in_addr_t, in_addr_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+in_addr_t inet_netof(struct in_addr) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/dirent-stubs.cpp b/lib/mlibc/options/posix/generic/dirent-stubs.cpp
new file mode 100644
index 0000000..1352585
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/dirent-stubs.cpp
@@ -0,0 +1,180 @@
+
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+
+#include <bits/ensure.h>
+#include <frg/allocation.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+
+// Code taken from musl
+int alphasort(const struct dirent **a, const struct dirent **b) {
+	return strcoll((*a)->d_name, (*b)->d_name);
+}
+
+int closedir(DIR *dir) {
+	// TODO: Deallocate the dir structure.
+	close(dir->__handle);
+	return 0;
+}
+int dirfd(DIR *dir) {
+	return dir->__handle;
+}
+DIR *fdopendir(int fd) {
+	struct stat st;
+
+	if(fstat(fd, &st) < 0) {
+		return nullptr;
+	}
+	// Musl implements this, but O_PATH is only declared on the linux abi
+	/*if(fcntl(fd, F_GETFL) & O_PATH) {
+		errno = EBADF;
+		return nullptr;
+	}*/
+	if(!S_ISDIR(st.st_mode)) {
+		errno = ENOTDIR;
+		return nullptr;
+	}
+	auto dir = frg::construct<__mlibc_dir_struct>(getAllocator());
+	__ensure(dir);
+	dir->__ent_next = 0;
+	dir->__ent_limit = 0;
+	int flags = fcntl(fd, F_GETFD);
+	fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+	dir->__handle = fd;
+	return dir;
+}
+DIR *opendir(const char *path) {
+	auto dir = frg::construct<__mlibc_dir_struct>(getAllocator());
+	__ensure(dir);
+	dir->__ent_next = 0;
+	dir->__ent_limit = 0;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_open_dir, nullptr);
+	if(int e = mlibc::sys_open_dir(path, &dir->__handle); e) {
+		errno = e;
+		frg::destruct(getAllocator(), dir);
+		return nullptr;
+	}else{
+		return dir;
+	}
+}
+struct dirent *readdir(DIR *dir) {
+	__ensure(dir->__ent_next <= dir->__ent_limit);
+	if(dir->__ent_next == dir->__ent_limit) {
+		MLIBC_CHECK_OR_ENOSYS(mlibc::sys_read_entries, nullptr);
+		if(int e = mlibc::sys_read_entries(dir->__handle, dir->__ent_buffer, 2048, &dir->__ent_limit); e)
+			__ensure(!"mlibc::sys_read_entries() failed");
+		dir->__ent_next = 0;
+		if(!dir->__ent_limit)
+			return nullptr;
+	}
+
+	auto entp = reinterpret_cast<struct dirent *>(dir->__ent_buffer + dir->__ent_next);
+	// We only copy as many bytes as we need to avoid buffer-overflows.
+	memcpy(&dir->__current, entp, offsetof(struct dirent, d_name) + strlen(entp->d_name) + 1);
+	dir->__ent_next += entp->d_reclen;
+	return &dir->__current;
+}
+int readdir_r(DIR *dir, struct dirent *entry, struct dirent **result) {
+	if(!mlibc::sys_read_entries) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+
+	__ensure(dir->__ent_next <= dir->__ent_limit);
+	if(dir->__ent_next == dir->__ent_limit) {
+		if(int e = mlibc::sys_read_entries(dir->__handle, dir->__ent_buffer, 2048, &dir->__ent_limit); e)
+			__ensure(!"mlibc::sys_read_entries() failed");
+		dir->__ent_next = 0;
+		if(!dir->__ent_limit) {
+			*result = NULL;
+			return 0;
+		}
+	}
+
+	auto entp = reinterpret_cast<struct dirent *>(dir->__ent_buffer + dir->__ent_next);
+	// We only copy as many bytes as we need to avoid buffer-overflows.
+	memcpy(entry, entp, offsetof(struct dirent, d_name) + strlen(entp->d_name) + 1);
+	dir->__ent_next += entp->d_reclen;
+	*result = entry;
+	return 0;
+}
+
+void rewinddir(DIR *dir) {
+	lseek(dir->__handle, 0, SEEK_SET);
+	dir->__ent_next = 0;
+}
+
+int scandir(const char *path, struct dirent ***res, int (*select)(const struct dirent *),
+		int (*compare)(const struct dirent **, const struct dirent **)) {
+	DIR *dir = opendir(path);
+	if (!dir)
+		return -1; // errno will be set by opendir()
+
+	// we should save the errno
+	int old_errno = errno;
+	errno = 0;
+
+	struct dirent *dir_ent;
+	struct dirent **array = nullptr, **tmp = nullptr;
+	int length = 0;
+	int count = 0;
+	while((dir_ent = readdir(dir)) && !errno) {
+		if(select && !select(dir_ent))
+			continue;
+
+		if(count >= length) {
+			length = 2*length + 1;
+			tmp = static_cast<struct dirent**>(realloc(array,
+						length * sizeof(struct dirent*)));
+			// we need to check the call actually goes through
+			// before we overwrite array so that we can
+			// deallocate the already written entries should realloc()
+			// have failed
+			if(!tmp)
+				break;
+			array = tmp;
+		}
+		array[count] = static_cast<struct dirent*>(malloc(dir_ent->d_reclen));
+		if(!array[count])
+			break;
+
+		memcpy(array[count], dir_ent, dir_ent->d_reclen);
+		count++;
+	}
+
+	if(errno) {
+		if(array)
+			while(count-- > 0)
+				free(array[count]);
+		free(array);
+		return -1;
+	}
+
+	// from here we can set the old errno back
+	errno = old_errno;
+
+	if(compare)
+		qsort(array, count, sizeof(struct dirent*),
+				(int (*)(const void *, const void *)) compare);
+	*res = array;
+	return count;
+}
+void seekdir(DIR *, long) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+long telldir(DIR *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int versionsort(const struct dirent **a, const struct dirent **b) {
+	return strverscmp((*a)->d_name, (*b)->d_name);
+}
diff --git a/lib/mlibc/options/posix/generic/dlfcn-stubs.cpp b/lib/mlibc/options/posix/generic/dlfcn-stubs.cpp
new file mode 100644
index 0000000..fc9fd84
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/dlfcn-stubs.cpp
@@ -0,0 +1,64 @@
+
+#include <bits/ensure.h>
+#include <dlfcn.h>
+
+#include <mlibc/debug.hpp>
+
+struct __dlapi_symbol {
+	const char *file;
+	void *base;
+	const char *symbol;
+	void *address;
+};
+
+extern "C" const char *__dlapi_error();
+extern "C" void *__dlapi_open(const char *, int, void *);
+extern "C" void *__dlapi_resolve(void *, const char *, void *);
+extern "C" int __dlapi_reverse(const void *, __dlapi_symbol *);
+extern "C" int __dlapi_close(void *);
+
+int dlclose(void *handle) {
+	return __dlapi_close(handle);
+}
+
+char *dlerror(void) {
+	return const_cast<char *>(__dlapi_error());
+}
+
+[[gnu::noinline]]
+void *dlopen(const char *file, int flags) {
+	auto ra = __builtin_extract_return_addr(__builtin_return_address(0));
+	return __dlapi_open(file, flags, ra);
+}
+
+[[gnu::noinline]]
+void *dlsym(void *__restrict handle, const char *__restrict string) {
+	auto ra = __builtin_extract_return_addr(__builtin_return_address(0));
+	return __dlapi_resolve(handle, string, ra);
+}
+
+[[gnu::noinline]]
+void *dlvsym(void *__restrict handle, const char *__restrict string, const char *__restrict version) {
+	mlibc::infoLogger() << "mlibc: dlvsym ignores version " << version << frg::endlog;
+	auto ra = __builtin_extract_return_addr(__builtin_return_address(0));
+	return __dlapi_resolve(handle, string, ra);
+}
+
+//gnu extensions
+int dladdr(const void *ptr, Dl_info *out) {
+	__dlapi_symbol info;
+	if(__dlapi_reverse(ptr, &info))
+		return 0;
+
+	out->dli_fname = info.file;
+	out->dli_fbase = info.base;
+	out->dli_sname = info.symbol;
+	out->dli_saddr = info.address;
+	return 1;
+}
+
+int dlinfo(void *, int, void *) {
+	__ensure(!"dlinfo() not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/fcntl-stubs.cpp b/lib/mlibc/options/posix/generic/fcntl-stubs.cpp
new file mode 100644
index 0000000..66e2d12
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/fcntl-stubs.cpp
@@ -0,0 +1,108 @@
+
+#include <errno.h>
+#include <bits/ensure.h>
+#include <fcntl.h>
+#include <stdarg.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int creat(const char *pathname, mode_t mode) {
+	return open(pathname, O_CREAT|O_WRONLY|O_TRUNC, mode);
+}
+
+int fallocate(int, int, off_t, off_t) {
+	mlibc::infoLogger() << "mlibc: fallocate() is a no-op" << frg::endlog;
+	errno = ENOSYS;
+	return -1;
+}
+
+int fcntl(int fd, int command, ...) {
+	va_list args;
+	va_start(args, command);
+	int result;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fcntl, -1);
+	if(int e = mlibc::sys_fcntl(fd, command, args, &result); e) {
+		errno = e;
+		return -1;
+	}
+	va_end(args);
+	return result;
+}
+
+int openat(int dirfd, const char *pathname, int flags, ...) {
+	va_list args;
+	va_start(args, flags);
+	mode_t mode = 0;
+	int fd;
+
+	if((flags & (O_CREAT | O_TMPFILE)))
+		mode = va_arg(args, mode_t);
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_openat, -1);
+	if(int e = mlibc::sys_openat(dirfd, pathname, flags, mode, &fd); e) {
+		errno = e;
+		return -1;
+	}
+	va_end(args);
+	return fd;
+}
+
+int posix_fadvise(int fd, off_t offset, off_t length, int advice) {
+	if(!mlibc::sys_fadvise) {
+		mlibc::infoLogger() << "mlibc: fadvise() ignored due to missing sysdep" << frg::endlog;
+		return 0;
+	}
+
+	// posix_fadvise() returns an error instead of setting errno.
+	return mlibc::sys_fadvise(fd, offset, length, advice);
+}
+
+int posix_fallocate(int fd, off_t offset, off_t size) {
+	// posix_fallocate() returns an error instead of setting errno.
+	if(!mlibc::sys_fallocate) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+	return mlibc::sys_fallocate(fd, offset, size);
+}
+
+// This is a linux extension
+int name_to_handle_at(int, const char *, struct file_handle *, int *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int open_by_handle_at(int, struct file_handle *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t splice(int, off_t *, int, off_t *, size_t, unsigned int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t vmsplice(int, const struct iovec *, size_t, unsigned int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int open(const char *pathname, int flags, ...) {
+	mode_t mode = 0;
+
+	if ((flags & O_CREAT) || (flags & O_TMPFILE)) {
+		va_list args;
+		va_start(args, flags);
+		mode = va_arg(args, mode_t);
+		va_end(args);
+	}
+
+	int fd;
+	if(int e = mlibc::sys_open(pathname, flags, mode, &fd); e) {
+		errno = e;
+		return -1;
+	}
+	return fd;
+}
+
diff --git a/lib/mlibc/options/posix/generic/ftw-stubs.cpp b/lib/mlibc/options/posix/generic/ftw-stubs.cpp
new file mode 100644
index 0000000..2d93995
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/ftw-stubs.cpp
@@ -0,0 +1,18 @@
+
+#include <ftw.h>
+
+#include <bits/ensure.h>
+
+int ftw(const char *, int (*fn)(const char *, const struct stat *, int), int) {
+	(void)fn;
+	__ensure(!"ftw() not implemented");
+	__builtin_unreachable();
+}
+
+int nftw(const char *, int (*fn)(const char *, const struct stat *, int, struct FTW *),
+		int, int) {
+	(void)fn;
+	__ensure(!"nftw() not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/grp-stubs.cpp b/lib/mlibc/options/posix/generic/grp-stubs.cpp
new file mode 100644
index 0000000..f8b2813
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/grp-stubs.cpp
@@ -0,0 +1,316 @@
+
+#include <grp.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+namespace {
+	FILE *global_file;
+
+	bool open_global_file() {
+		if(!global_file) {
+			global_file = fopen("/etc/group", "r");
+			if(!global_file) {
+				errno = EIO;
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	void close_global_file() {
+		if(global_file) {
+			fclose(global_file);
+			global_file = nullptr;
+		}
+	}
+
+	template<typename F>
+	void walk_segments(frg::string_view line, char delimiter, F fn) {
+		size_t s = 0;
+		while(true) {
+			size_t d = line.find_first(delimiter, s);
+			if(d == size_t(-1))
+				break;
+			auto chunk = line.sub_string(s, d - s);
+			fn(chunk);
+			s = d + 1;
+		}
+		if(line[s]) {
+			auto chunk = line.sub_string(s, line.size() - s);
+
+			if (chunk.size() > 0) {
+				// Remove trailing newline
+				if (chunk[chunk.size() - 1] == '\n')
+					chunk = chunk.sub_string(0, chunk.size() - 1);
+
+				fn(chunk);
+			}
+		}
+	}
+
+	bool extract_entry(frg::string_view line, group *entry) {
+		frg::string_view segments[5];
+
+		// Parse the line into 3 or 4 segments (depending if the group has members or not)
+		int n = 0;
+		walk_segments(line, ':', [&] (frg::string_view s) {
+			__ensure(n < 4);
+			segments[n++] = s;
+		});
+
+		if(n < 3) // n can be 3 when there are no members in the group
+			return false;
+
+		// TODO: Handle strndup() and malloc() failure.
+		auto name = strndup(segments[0].data(), segments[0].size());
+		__ensure(name);
+
+		auto passwd = strndup(segments[1].data(), segments[1].size());
+
+		auto gid = segments[2].to_number<int>();
+		if(!gid)
+			return false;
+
+		size_t n_members = 0;
+		walk_segments(segments[3], ',', [&] (frg::string_view) {
+			n_members++;
+		});
+
+		auto members = reinterpret_cast<char **>(malloc(sizeof(char *) * (n_members + 1)));
+		__ensure(members);
+		size_t k = 0;
+		walk_segments(segments[3], ',', [&] (frg::string_view m) {
+			members[k] = strndup(m.data(), m.size());
+			__ensure(members[k]);
+			k++;
+		});
+		members[k] = nullptr;
+
+		entry->gr_name = name;
+		entry->gr_passwd = passwd;
+		entry->gr_gid = *gid;
+		entry->gr_mem = members;
+		return true;
+	}
+
+	void clear_entry(group *entry) {
+		free(entry->gr_name);
+		if(entry->gr_mem) {
+			for(size_t i = 0; entry->gr_mem[i]; i++)
+				free(entry->gr_mem[i]);
+			free(entry->gr_mem);
+		}
+		entry->gr_name = nullptr;
+		entry->gr_mem = nullptr;
+	}
+
+	template<typename C>
+	int walk_file(struct group *entry, C cond) {
+		auto file = fopen("/etc/group", "r");
+		if(!file) {
+			return EIO;
+		}
+
+		char line[512];
+		while(fgets(line, 512, file)) {
+			if(!extract_entry(line, entry))
+				continue;
+			if(cond(entry)) {
+				fclose(file);
+				return 0;
+			}
+		}
+
+		int err = ESRCH;
+		if(ferror(file)) {
+			err = EIO;
+		}
+
+		fclose(file);
+		return err;
+	}
+
+	int copy_to_buffer(struct group *grp, char *buffer, size_t size) {
+		// Adjust to correct alignment so that we can put gr_mem first in buffer
+		uintptr_t mask = sizeof(char *) - 1;
+		size_t offset = (reinterpret_cast<uintptr_t>(buffer) % sizeof(char *) + mask) & ~mask;
+		if (size < offset)
+			return ERANGE;
+
+		buffer += offset;
+		size -= offset;
+
+		// Calculate the amount of space we need
+		size_t nmemb, required_size = 0;
+		for (nmemb = 0; grp->gr_mem[nmemb] != nullptr; nmemb++) {
+			// One for the string's null terminator and one for the pointer in gr_mem
+			required_size += strlen(grp->gr_mem[nmemb]) + 1 + sizeof(char *);
+		}
+
+		// One for null terminator of gr_name, plus sizeof(char *) for nullptr terminator of gr_mem
+		required_size += strlen(grp->gr_name) + 1 + sizeof(char *);
+		if (size < required_size)
+			return ERANGE;
+
+		// Put the gr_mem array first in the buffer as we are guaranteed
+		// that the pointer is aligned correctly
+		char *string_data = buffer + (nmemb + 1) * sizeof(char *);
+
+		for (size_t i = 0; i < nmemb; i++) {
+			reinterpret_cast<char **>(buffer)[i] = string_data;
+			string_data = stpcpy(string_data, grp->gr_mem[i]) + 1;
+			free(grp->gr_mem[i]);
+		}
+
+		reinterpret_cast<char **>(buffer)[nmemb] = nullptr;
+		free(grp->gr_mem);
+		grp->gr_mem = reinterpret_cast<char **>(buffer);
+
+		char *gr_name = stpcpy(string_data, grp->gr_name) + 1;
+		free(grp->gr_name);
+		grp->gr_name = string_data;
+
+		__ensure(gr_name <= buffer + size);
+		return 0;
+	}
+}
+
+void endgrent(void) {
+	close_global_file();
+}
+
+struct group *getgrent(void) {
+	static group entry;
+	char line[512];
+
+	if(!open_global_file()) {
+		return nullptr;
+	}
+
+	if(fgets(line, 512, global_file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry)) {
+			errno = EINVAL;
+			return nullptr;
+		}
+		return &entry;
+	}
+
+	if(ferror(global_file)) {
+		errno = EIO;
+	}
+
+	return nullptr;
+}
+
+struct group *getgrgid(gid_t gid) {
+	static group entry;
+
+	int err = walk_file(&entry, [&] (group *entry) {
+		return entry->gr_gid == gid;
+	});
+
+	if (err) {
+		errno = err;
+		return nullptr;
+	}
+
+	return &entry;
+}
+
+int getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t size, struct group **result) {
+	*result = nullptr;
+	int err = walk_file(grp, [&] (group *entry) {
+		return entry->gr_gid == gid;
+	});
+
+	if (err) {
+		return err;
+	}
+
+	err = copy_to_buffer(grp, buffer, size);
+	if (err) {
+		return err;
+	}
+
+	*result = grp;
+	return 0;
+}
+
+struct group *getgrnam(const char *name) {
+	static group entry;
+
+	int err = walk_file(&entry, [&] (group *entry) {
+		return !strcmp(entry->gr_name, name);
+	});
+
+	if (err) {
+		errno = err;
+		return nullptr;
+	}
+
+	return &entry;
+}
+
+int getgrnam_r(const char *name, struct group *grp, char *buffer, size_t size, struct group **result) {
+	*result = nullptr;
+
+	int err = walk_file(grp, [&] (group *entry) {
+		return !strcmp(entry->gr_name, name);
+	});
+
+	if (err) {
+		return err;
+	}
+
+	err = copy_to_buffer(grp, buffer, size);
+	if (err) {
+		return err;
+	}
+
+	*result = grp;
+	return 0;
+}
+
+void setgrent(void) {
+	if(!open_global_file()) {
+		return;
+	}
+	rewind(global_file);
+}
+
+int setgroups(size_t size, const gid_t *list) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setgroups, -1);
+	if(int e = mlibc::sys_setgroups(size, list); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int initgroups(const char *, gid_t) {
+	mlibc::infoLogger() << "mlibc: initgroups is a stub" << frg::endlog;
+	return 0;
+}
+
+int putgrent(const struct group *, FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct group *fgetgrent(FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getgrouplist(const char *, gid_t, gid_t *, int *) {
+	mlibc::infoLogger() << "mlibc: getgrouplist is a stub" << frg::endlog;
+	return 0;
+}
diff --git a/lib/mlibc/options/posix/generic/langinfo-stubs.cpp b/lib/mlibc/options/posix/generic/langinfo-stubs.cpp
new file mode 100644
index 0000000..b239cbd
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/langinfo-stubs.cpp
@@ -0,0 +1,15 @@
+
+#include <langinfo.h>
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/locale.hpp>
+
+char *nl_langinfo(nl_item item) {
+	return mlibc::nl_langinfo(item);
+}
+
+char *nl_langinfo_l(nl_item, locale_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/libgen-stubs.cpp b/lib/mlibc/options/posix/generic/libgen-stubs.cpp
new file mode 100644
index 0000000..ff80349
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/libgen-stubs.cpp
@@ -0,0 +1,51 @@
+
+#include <bits/ensure.h>
+#include <libgen.h>
+#include <string.h>
+
+#include <mlibc/debug.hpp>
+
+// Adopted from musl's code.
+char *basename(char *s) {
+	// This empty string behavior is specified by POSIX.
+	if (!s || !*s)
+		return const_cast<char *>(".");
+	
+	// Delete trailing slashes.
+	// Note that we do not delete the slash at index zero.
+	auto i = strlen(s) - 1;
+	for(; i && s[i] == '/'; i--)
+		s[i] = 0;
+
+	// Find the last non-trailing slash.
+	for(; i && s[i - 1] != '/'; i--)
+		;
+	return s + i;
+}
+
+char *dirname(char *s) {
+	if (!s || !(*s))
+		return const_cast<char *>(".");
+
+	auto i = strlen(s) - 1;
+
+	// Skip trailing slashes.
+	for (; s[i] == '/'; i--)
+		if(!i) // Path only consists of slashes.
+			return const_cast<char *>("/");
+
+	// Skip the last non-slash path component.
+	for (; s[i] != '/'; i--)
+		if(!i) // Path only contains a single component.
+			return const_cast<char *>(".");
+
+	// Skip slashes.
+	for (; s[i] == '/'; i--)
+		if(!i) // Path is entry in root directory.
+			return const_cast<char *>("/");
+
+	s[i+1] = 0;
+
+	return s;
+}
+
diff --git a/lib/mlibc/options/posix/generic/lookup.cpp b/lib/mlibc/options/posix/generic/lookup.cpp
new file mode 100644
index 0000000..f877fe5
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/lookup.cpp
@@ -0,0 +1,512 @@
+#include <mlibc/lookup.hpp>
+#include <mlibc/resolv_conf.hpp>
+#include <mlibc/debug.hpp>
+#include <bits/ensure.h>
+
+#include <frg/string.hpp>
+#include <mlibc/allocator.hpp>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <ctype.h>
+
+namespace mlibc {
+
+namespace {
+	constexpr unsigned int RECORD_A = 1;
+	constexpr unsigned int RECORD_CNAME = 5;
+	constexpr unsigned int RECORD_PTR = 12;
+}
+
+static frg::string<MemoryAllocator> read_dns_name(char *buf, char *&it) {
+	frg::string<MemoryAllocator> res{getAllocator()};
+	while (true) {
+		char code = *it++;
+		if ((code & 0xC0) == 0xC0) {
+			// pointer
+			uint8_t offset = ((code & 0x3F) << 8) | *it++;
+			auto offset_it = buf + offset;
+			return res + read_dns_name(buf, offset_it);
+		} else if (!(code & 0xC0)) {
+			if (!code)
+				break;
+
+			for (int i = 0; i < code; i++)
+				res += (*it++);
+
+			if (*it)
+				res += '.';
+		} else {
+			break;
+		}
+	}
+
+	return res;
+}
+
+int lookup_name_dns(struct lookup_result &buf, const char *name,
+		frg::string<MemoryAllocator> &canon_name) {
+	frg::string<MemoryAllocator> request{getAllocator()};
+
+	int num_q = 1;
+	struct dns_header header;
+	header.identification = htons(123);
+	header.flags = htons(0x100);
+	header.no_q = htons(num_q);
+	header.no_ans = htons(0);
+	header.no_auths = htons(0);
+	header.no_additional = htons(0);
+
+	request.resize(sizeof(header));
+	memcpy(request.data(), &header, sizeof(header));
+
+	const char *end = name;
+	while (*end != '\0') {
+		end = strchrnul(name, '.');
+		size_t length = end - name;
+		frg::string_view substring{name, length};
+		name += length + 1;
+		request += char(length);
+		request += substring;
+	}
+
+	request += char(0);
+	// set question type to fetch A records
+	request += 0;
+	request += 1;
+	// set CLASS to IN
+	request += 0;
+	request += 1;
+
+	struct sockaddr_in sin = {};
+	sin.sin_family = AF_INET;
+	// TODO(geert): we could probably make this use the service lookup
+	// for dns
+	sin.sin_port = htons(53);
+
+	auto nameserver = get_nameserver();
+	if (!inet_aton(nameserver ? nameserver->name.data() : "127.0.0.1", &sin.sin_addr)) {
+		mlibc::infoLogger() << "lookup_name_dns(): inet_aton() failed!" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	int fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		mlibc::infoLogger() << "lookup_name_dns(): socket() failed" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	size_t sent = sendto(fd, request.data(), request.size(), 0,
+			(struct sockaddr*)&sin, sizeof(sin));
+	if (sent != request.size()) {
+		mlibc::infoLogger() << "lookup_name_dns(): sendto() failed to send everything" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	char response[256];
+	ssize_t rlen;
+	int num_ans = 0;
+	while ((rlen = recvfrom(fd, response, 256, 0, NULL, NULL)) >= 0) {
+		if ((size_t)rlen < sizeof(struct dns_header))
+			continue;
+		auto response_header = reinterpret_cast<struct dns_header*>(response);
+		if (response_header->identification != header.identification)
+			return -EAI_FAIL;
+
+		auto it = response + sizeof(struct dns_header);
+		for (int i = 0; i < ntohs(response_header->no_q); i++) {
+			auto dns_name = read_dns_name(response, it);
+			(void) dns_name;
+			it += 4;
+		}
+
+		for (int i = 0; i < ntohs(response_header->no_ans); i++) {
+			struct dns_addr_buf buffer;
+			auto dns_name = read_dns_name(response, it);
+
+			uint16_t rr_type = (it[0] << 8) | it[1];
+			uint16_t rr_class = (it[2] << 8) | it[3];
+			uint16_t rr_length = (it[8] << 8) | it[9];
+			it += 10;
+			(void)rr_class;
+
+			switch (rr_type) {
+				case RECORD_A:
+					memcpy(buffer.addr, it, rr_length);
+					it += rr_length;
+					buffer.family = AF_INET;
+					buffer.name = std::move(dns_name);
+					buf.buf.push(std::move(buffer));
+					break;
+				case RECORD_CNAME:
+					canon_name = read_dns_name(response, it);
+					buf.aliases.push(std::move(dns_name));
+					break;
+				default:
+					mlibc::infoLogger() << "lookup_name_dns: unknown rr type "
+						<< rr_type << frg::endlog;
+					break;
+			}
+		}
+		num_ans += ntohs(response_header->no_ans);
+
+		if (num_ans >= num_q)
+			break;
+	}
+
+	close(fd);
+	return buf.buf.size();
+}
+
+int lookup_addr_dns(frg::span<char> name, frg::array<uint8_t, 16> &addr, int family) {
+	frg::string<MemoryAllocator> request{getAllocator()};
+
+	int num_q = 1;
+	struct dns_header header;
+	header.identification = htons(123);
+	header.flags = htons(0x100);
+	header.no_q = htons(num_q);
+	header.no_ans = htons(0);
+	header.no_auths = htons(0);
+	header.no_additional = htons(0);
+
+	request.resize(sizeof(header));
+	memcpy(request.data(), &header, sizeof(header));
+
+	char addr_str[64];
+	if(!inet_ntop(family, addr.data(), addr_str, sizeof(addr_str))) {
+		switch(errno) {
+			case EAFNOSUPPORT:
+				return -EAI_FAMILY;
+			case ENOSPC:
+				return -EAI_OVERFLOW;
+			default:
+				return -EAI_FAIL;
+		}
+	}
+	frg::string<MemoryAllocator> req_str{getAllocator(), addr_str};
+	req_str += ".in-addr.arpa";
+
+	frg::string_view req_view{req_str.data(), req_str.size()};
+	size_t ptr = 0;
+	do {
+		size_t next = req_view.find_first('.', ptr);
+		size_t length = next != (size_t)-1 ? next - ptr : req_view.size() - ptr;
+		frg::string_view substring = req_view.sub_string(ptr, length);
+		request += char(length);
+		request += substring;
+		ptr = next + 1;
+	} while(ptr != 0);
+
+	request += char(0);
+	// set question type to fetch PTR records
+	request += 0;
+	request += 12;
+	// set CLASS to IN
+	request += 0;
+	request += 1;
+
+
+	struct sockaddr_in sin = {};
+	sin.sin_family = AF_INET;
+	// TODO(geert): we could probably make this use the service lookup
+	// for dns
+	sin.sin_port = htons(53);
+
+	auto nameserver = get_nameserver();
+	if (!inet_aton(nameserver ? nameserver->name.data() : "127.0.0.1", &sin.sin_addr)) {
+		mlibc::infoLogger() << "lookup_name_dns(): inet_aton() failed!" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	int fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		mlibc::infoLogger() << "lookup_name_dns(): socket() failed" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	size_t sent = sendto(fd, request.data(), request.size(), 0,
+			(struct sockaddr*)&sin, sizeof(sin));
+	if (sent != request.size()) {
+		mlibc::infoLogger() << "lookup_name_dns(): sendto() failed to send everything" << frg::endlog;
+		return -EAI_SYSTEM;
+	}
+
+	char response[256];
+	ssize_t rlen;
+	int num_ans = 0;
+	while ((rlen = recvfrom(fd, response, 256, 0, NULL, NULL)) >= 0) {
+		if ((size_t)rlen < sizeof(struct dns_header))
+			continue;
+		auto response_header = reinterpret_cast<struct dns_header*>(response);
+		if (response_header->identification != header.identification)
+			return -EAI_FAIL;
+
+		auto it = response + sizeof(struct dns_header);
+		for (int i = 0; i < ntohs(response_header->no_q); i++) {
+			auto dns_name = read_dns_name(response, it);
+			(void) dns_name;
+			it += 4;
+		}
+
+		for (int i = 0; i < ntohs(response_header->no_ans); i++) {
+			struct dns_addr_buf buffer;
+			auto dns_name = read_dns_name(response, it);
+
+			uint16_t rr_type = (it[0] << 8) | it[1];
+			uint16_t rr_class = (it[2] << 8) | it[3];
+			uint16_t rr_length = (it[8] << 8) | it[9];
+			it += 10;
+			(void)rr_class;
+			(void)rr_length;
+
+			(void)dns_name;
+
+			switch (rr_type) {
+				case RECORD_PTR: {
+					auto ptr_name = read_dns_name(response, it);
+					if (ptr_name.size() >= name.size())
+						return -EAI_OVERFLOW;
+					std::copy(ptr_name.begin(), ptr_name.end(), name.data());
+					name.data()[ptr_name.size()] = '\0';
+					return 1;
+				}
+				default:
+					mlibc::infoLogger() << "lookup_addr_dns: unknown rr type "
+						<< rr_type << frg::endlog;
+					break;
+			}
+			num_ans += ntohs(response_header->no_ans);
+
+			if (num_ans >= num_q)
+				break;
+		}
+	}
+
+	close(fd);
+	return 0;
+}
+
+int lookup_name_hosts(struct lookup_result &buf, const char *name,
+		frg::string<MemoryAllocator> &canon_name) {
+	auto file = fopen("/etc/hosts", "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line[128];
+	int name_length = strlen(name);
+	while (fgets(line, 128, file)) {
+		char *pos;
+		// same way to deal with comments as in services.cpp
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		for(pos = line + 1; (pos = strstr(pos, name)) &&
+				(!isspace(pos[-1]) || !isspace(pos[name_length])); pos++);
+		if (!pos)
+			continue;
+
+		for (pos = line; !isspace(*pos); pos++);
+		*pos = '\0';
+
+		// TODO(geert): we assume ipv4 for now
+		struct in_addr addr;
+		if (!inet_aton(line, &addr))
+			continue;
+
+		pos++;
+		for(; *pos && isspace(*pos); pos++);
+		char *end;
+		for(end = pos; *end && !isspace(*end); end++);
+
+		struct dns_addr_buf buffer;
+		memcpy(buffer.addr, &addr, 4);
+		buffer.family = AF_INET;
+		buffer.name = frg::string<MemoryAllocator>{pos,
+			static_cast<size_t>(end - pos), getAllocator()};
+		canon_name = buffer.name;
+
+		buf.buf.push(std::move(buffer));
+
+		pos = end;
+		while (pos[1]) {
+			for (; *pos && isspace(*pos); pos++);
+			for (end = pos; *end && !isspace(*end); end++);
+			auto name = frg::string<MemoryAllocator>{pos,
+				static_cast<size_t>(end - pos), getAllocator()};
+			buf.aliases.push(std::move(name));
+			pos = end;
+		}
+	}
+
+	fclose(file);
+	return buf.buf.size();
+}
+
+int lookup_addr_hosts(frg::span<char> name, frg::array<uint8_t, 16> &addr, int family) {
+	auto file = fopen("/etc/hosts", "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	// Buffer to hold ASCII version of address
+	char addr_str[64];
+	if(!inet_ntop(family, addr.data(), addr_str, sizeof(addr_str))) {
+		switch(errno) {
+			case EAFNOSUPPORT:
+				return -EAI_FAMILY;
+			case ENOSPC:
+				return -EAI_OVERFLOW;
+			default:
+				return -EAI_FAIL;
+		}
+	}
+	int addr_str_len = strlen(addr_str);
+
+	char line[128];
+	while (fgets(line, 128, file)) {
+		char *pos;
+		// same way to deal with comments as in services.cpp
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+		if (strncmp(line, addr_str, addr_str_len))
+			continue;
+
+		for (pos = line + addr_str_len + 1; isspace(*pos); pos++);
+		char *begin = pos;
+		for (; !isspace(*pos); pos++);
+		char *end = pos;
+
+		size_t size = end - begin;
+		if (size >= name.size())
+			return -EAI_OVERFLOW;
+		std::copy(begin, end, name.data());
+		name.data()[size] = '\0';
+		return 1;
+	}
+	return 0;
+}
+
+int lookup_name_null(struct lookup_result &buf, int flags, int family) {
+	if (flags & AI_PASSIVE) {
+		if (family != AF_INET6) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET;
+
+			in_addr_t addr = INADDR_ANY;
+			memcpy(&addr_buf.addr, &addr, 4);
+
+			buf.buf.push_back(addr_buf);
+		}
+		if (family != AF_INET) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET6;
+
+			struct in6_addr addr = IN6ADDR_ANY_INIT;
+			memcpy(&addr_buf.addr, &addr, 16);
+
+			buf.buf.push_back(addr_buf);
+		}
+	} else {
+		if (family != AF_INET6) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET;
+
+			in_addr_t addr = INADDR_LOOPBACK;
+			memcpy(&addr_buf.addr, &addr, 4);
+
+			buf.buf.push_back(addr_buf);
+		}
+		if (family != AF_INET) {
+			struct dns_addr_buf addr_buf;
+			addr_buf.family = AF_INET6;
+
+			struct in6_addr addr = IN6ADDR_LOOPBACK_INIT;
+			memcpy(&addr_buf.addr, &addr, 16);
+
+			buf.buf.push_back(addr_buf);
+		}
+	}
+	return buf.buf.size();
+}
+
+int lookup_name_ip(struct lookup_result &buf, const char *name, int family) {
+	if (family == AF_INET) {
+		in_addr_t addr = 0;
+		int res = inet_pton(AF_INET, name, &addr);
+
+		if (res <= 0)
+			return -EAI_NONAME;
+
+		struct dns_addr_buf addr_buf;
+		addr_buf.family = AF_INET;
+		memcpy(&addr_buf.addr, &addr, 4);
+
+		buf.buf.push_back(addr_buf);
+		return 1;
+	}
+
+	if (family == AF_INET6) {
+		struct in6_addr addr{0};
+		int res = inet_pton(AF_INET6, name, &addr);
+
+		if (res <= 0)
+			return -EAI_NONAME;
+
+		struct dns_addr_buf addr_buf;
+		addr_buf.family = AF_INET6;
+		memcpy(&addr_buf.addr, &addr, 16);
+
+		buf.buf.push_back(addr_buf);
+		return 1;
+	}
+
+	// If no family was specified we try ipv4 and then ipv6.
+	in_addr_t addr4 = 0;
+	int res = inet_pton(AF_INET, name, &addr4);
+
+	if (res > 0) {
+		struct dns_addr_buf addr_buf;
+		addr_buf.family = AF_INET;
+		memcpy(&addr_buf.addr, &addr4, 4);
+
+		buf.buf.push_back(addr_buf);
+		return 1;
+	}
+
+	struct in6_addr addr6{0};
+	res = inet_pton(AF_INET6, name, &addr6);
+
+	if (res <= 0)
+		return -EAI_NONAME;
+
+	struct dns_addr_buf addr_buf;
+	addr_buf.family = AF_INET6;
+	memcpy(&addr_buf.addr, &addr6, 16);
+
+	buf.buf.push_back(addr_buf);
+	return 1;
+}
+
+} // namespace mlibc
diff --git a/lib/mlibc/options/posix/generic/mqueue.cpp b/lib/mlibc/options/posix/generic/mqueue.cpp
new file mode 100644
index 0000000..d635419
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/mqueue.cpp
@@ -0,0 +1,22 @@
+#include <mqueue.h>
+#include <bits/ensure.h>
+
+int mq_getattr(mqd_t, struct mq_attr *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int mq_setattr(mqd_t, const struct mq_attr *__restrict__, struct mq_attr *__restrict__) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int mq_unlink(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+mqd_t mq_open(const char *, int, ...) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/net-if-stubs.cpp b/lib/mlibc/options/posix/generic/net-if-stubs.cpp
new file mode 100644
index 0000000..6a65a5c
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/net-if-stubs.cpp
@@ -0,0 +1,40 @@
+#include <errno.h>
+#include <net/if.h>
+#include <stdlib.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+void if_freenameindex(struct if_nameindex *) {
+	mlibc::infoLogger() << "mlibc: if_freenameindex is a no-op" << frg::endlog;
+}
+
+char *if_indextoname(unsigned int index, char *name) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_if_indextoname, NULL);
+
+	if(int e = sysdep(index, name); e) {
+		errno = e;
+		return NULL;
+	}
+
+	return name;
+}
+
+struct if_nameindex *if_nameindex(void) {
+	mlibc::infoLogger() << "mlibc: if_nameindex() is a no-op" << frg::endlog;
+	errno = ENOSYS;
+	return NULL;
+}
+
+unsigned int if_nametoindex(const char *name) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_if_nametoindex, 0);
+	unsigned int ret = 0;
+
+	if(int e = sysdep(name, &ret); e) {
+		errno = e;
+		return 0;
+	}
+
+	return ret;
+}
diff --git a/lib/mlibc/options/posix/generic/netdb-stubs.cpp b/lib/mlibc/options/posix/generic/netdb-stubs.cpp
new file mode 100644
index 0000000..455444b
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/netdb-stubs.cpp
@@ -0,0 +1,486 @@
+#include <netdb.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/lookup.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/services.hpp>
+#include <frg/vector.hpp>
+#include <frg/array.hpp>
+#include <frg/span.hpp>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <errno.h>
+
+__thread int __mlibc_h_errno;
+
+// This function is from musl
+int *__h_errno_location(void) {
+	return &__mlibc_h_errno;
+}
+
+void endhostent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endnetent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endprotoent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endservent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void freeaddrinfo(struct addrinfo *ptr) {
+	if (ptr) {
+		auto buf = (struct mlibc::ai_buf*) ptr - offsetof(struct mlibc::ai_buf, ai);
+		// this string was allocated by a frg::string
+		getAllocator().free(ptr->ai_canonname);
+		free(buf);
+	}
+}
+
+const char *gai_strerror(int code) {
+	static thread_local char buffer[128];
+	snprintf(buffer, sizeof(buffer), "Unknown error (%d)", code);
+	return buffer;
+}
+
+int getaddrinfo(const char *__restrict node, const char *__restrict service,
+		const struct addrinfo *__restrict hints, struct addrinfo **__restrict res) {
+	if (!node && !service)
+		return EAI_NONAME;
+
+	int socktype = 0, protocol = 0, family = AF_UNSPEC, flags = AI_V4MAPPED | AI_ADDRCONFIG;
+	if (hints) {
+		socktype = hints->ai_socktype;
+		protocol = hints->ai_protocol;
+		family = hints->ai_family;
+		flags = hints->ai_flags;
+
+		int mask = AI_V4MAPPED | AI_ADDRCONFIG | AI_NUMERICHOST | AI_PASSIVE |
+			AI_CANONNAME | AI_ALL | AI_NUMERICSERV;
+		if ((flags & mask) != flags)
+			return EAI_BADFLAGS;
+
+		if (family != AF_INET && family != AF_INET6 && family != AF_UNSPEC)
+			return EAI_FAMILY;
+	}
+
+	mlibc::service_result serv_buf{getAllocator()};
+	int serv_count = mlibc::lookup_serv_by_name(serv_buf, service, protocol, socktype, flags);
+	if (serv_count < 0)
+		return -serv_count;
+
+	struct mlibc::lookup_result addr_buf;
+	int addr_count = 1;
+	frg::string<MemoryAllocator> canon{getAllocator()};
+	if (node) {
+		if ((addr_count = mlibc::lookup_name_ip(addr_buf, node, family)) <= 0) {
+			if (flags & AI_NUMERICHOST)
+			       addr_count = -EAI_NONAME;
+			else if ((addr_count = mlibc::lookup_name_hosts(addr_buf, node, canon)) <= 0)
+				addr_count = mlibc::lookup_name_dns(addr_buf, node, canon);
+			else
+				addr_count = 1;
+		}
+
+		if (addr_count < 0)
+			return -addr_count;
+		if (!addr_count)
+			return EAI_NONAME;
+	} else {
+		/* There is no node specified */
+		if (flags & AI_NUMERICHOST)
+			return EAI_NONAME;
+		addr_count = lookup_name_null(addr_buf, flags, family);
+	}
+
+	auto out = (struct mlibc::ai_buf *) calloc(serv_count * addr_count,
+			sizeof(struct mlibc::ai_buf));
+
+	if (node && !canon.size())
+		canon = frg::string<MemoryAllocator>{node, getAllocator()};
+
+	for (int i = 0, k = 0; i < addr_count; i++) {
+		for (int j = 0; j < serv_count; j++, k++) {
+			out[i].ai.ai_family = addr_buf.buf[i].family;
+			out[i].ai.ai_socktype = serv_buf[j].socktype;
+			out[i].ai.ai_protocol = serv_buf[j].protocol;
+			out[i].ai.ai_flags = flags;
+			out[i].ai.ai_addr = (struct sockaddr *) &out[i].sa;
+			if (canon.size())
+				out[i].ai.ai_canonname = canon.data();
+			else
+				out[i].ai.ai_canonname = NULL;
+			out[i].ai.ai_next = NULL;
+			switch (addr_buf.buf[i].family) {
+				case AF_INET:
+					out[i].ai.ai_addrlen = sizeof(struct sockaddr_in);
+					out[i].sa.sin.sin_port = htons(serv_buf[j].port);
+					out[i].sa.sin.sin_family = AF_INET;
+					memcpy(&out[i].sa.sin.sin_addr, addr_buf.buf[i].addr, 4);
+					break;
+				case AF_INET6:
+					out[i].ai.ai_addrlen = sizeof(struct sockaddr_in6);
+					out[i].sa.sin6.sin6_family = htons(serv_buf[j].port);
+					out[i].sa.sin6.sin6_family = AF_INET6;
+					memcpy(&out[i].sa.sin6.sin6_addr, addr_buf.buf[i].addr, 16);
+					break;
+			}
+		}
+	}
+	if (canon.size())
+		canon.detach();
+
+	*res = &out[0].ai;
+	return 0;
+}
+
+struct hostent *gethostent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getnameinfo(const struct sockaddr *__restrict addr, socklen_t addr_len,
+		char *__restrict host, socklen_t host_len, char *__restrict serv,
+		socklen_t serv_len, int flags) {
+	frg::array<uint8_t, 16> addr_array;
+	int family = addr->sa_family;
+
+	switch(family) {
+		case AF_INET: {
+			if (addr_len < sizeof(struct sockaddr_in))
+				return EAI_FAMILY;
+			auto sockaddr = reinterpret_cast<const struct sockaddr_in*>(addr);
+			memcpy(addr_array.data(), reinterpret_cast<const char*>(&sockaddr->sin_addr), 4);
+			break;
+		}
+		case AF_INET6: {
+			mlibc::infoLogger() << "getnameinfo(): ipv6 is not fully supported in this function" << frg::endlog;
+			if (addr_len < sizeof(struct sockaddr_in6))
+				return EAI_FAMILY;
+			auto sockaddr = reinterpret_cast<const struct sockaddr_in6*>(addr);
+			memcpy(addr_array.data(), reinterpret_cast<const char*>(&sockaddr->sin6_addr), 16);
+			break;
+		}
+		default:
+			return EAI_FAMILY;
+	}
+
+	if (host && host_len) {
+		frg::span<char> host_span{host, host_len};
+		int res = 0;
+		if (!(flags & NI_NUMERICHOST))
+			res = mlibc::lookup_addr_hosts(host_span, addr_array, family);
+		if (!(flags & NI_NUMERICHOST) && !res)
+			res = mlibc::lookup_addr_dns(host_span, addr_array, family);
+
+		if (!res) {
+			if (flags & NI_NAMEREQD)
+				return EAI_NONAME;
+			if(!inet_ntop(family, addr_array.data(), host, host_len)) {
+				switch(errno) {
+					case EAFNOSUPPORT:
+						return EAI_FAMILY;
+					case ENOSPC:
+						return EAI_OVERFLOW;
+					default:
+						return EAI_FAIL;
+				}
+			}
+		}
+
+		if (res < 0)
+			return -res;
+	}
+
+	if (serv && serv_len) {
+		__ensure("getnameinfo(): not implemented service resolution yet!");
+		__builtin_unreachable();
+	}
+
+	return 0;
+}
+
+struct netent *getnetbyaddr(uint32_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct netent *getnetbyname(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct netent *getnetent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct hostent *gethostbyname(const char *name) {
+	if (!name) {
+		h_errno = HOST_NOT_FOUND;
+		return NULL;
+	}
+
+	struct mlibc::lookup_result buf;
+	frg::string<MemoryAllocator> canon{getAllocator()};
+	int ret = 0;
+	if ((ret = mlibc::lookup_name_hosts(buf, name, canon)) <= 0)
+		ret = mlibc::lookup_name_dns(buf, name, canon);
+	if (ret <= 0) {
+		h_errno = HOST_NOT_FOUND;
+		return NULL;
+	}
+
+	static struct hostent h;
+	if (h.h_name) {
+		getAllocator().free(h.h_name);
+		for (int i = 0; h.h_aliases[i] != NULL; i++)
+			getAllocator().free(h.h_aliases[i]);
+		free(h.h_aliases);
+
+		if (h.h_addr_list) {
+			for (int i = 0; h.h_addr_list[i] != NULL; i++)
+				free(h.h_addr_list[i]);
+			free(h.h_addr_list);
+		}
+	}
+	h = {};
+
+	if (!canon.size())
+		canon = frg::string<MemoryAllocator>{name, getAllocator()};
+
+	h.h_name = canon.data();
+
+	h.h_aliases = reinterpret_cast<char**>(malloc((buf.aliases.size() + 1)
+				* sizeof(char*)));
+	int alias_pos = 0;
+	for (auto &buf_name : buf.aliases) {
+		h.h_aliases[alias_pos] = buf_name.data();
+		buf_name.detach();
+		alias_pos++;
+	}
+	h.h_aliases[alias_pos] = NULL;
+	canon.detach();
+
+	// just pick the first family as the one for all addresses...??
+	h.h_addrtype = buf.buf[0].family;
+	if (h.h_addrtype != AF_INET && h.h_addrtype != AF_INET6) {
+		// this is not allowed per spec
+		h_errno = NO_DATA;
+		return NULL;
+	}
+
+	// can only be AF_INET or AF_INET6
+	h.h_length = h.h_addrtype == AF_INET ? 4 : 16;
+	h.h_addr_list = reinterpret_cast<char**>(malloc((ret + 1) * sizeof(char*)));
+	int addr_pos = 0;
+	for (int i = 0; i < ret; i++) {
+		if (buf.buf[i].family != h.h_addrtype)
+			continue;
+		h.h_addr_list[addr_pos] = reinterpret_cast<char*>(malloc(h.h_length));
+		memcpy(h.h_addr_list[addr_pos], buf.buf[i].addr, h.h_length);
+		addr_pos++;
+	}
+	h.h_addr_list[addr_pos] = NULL;
+
+	return &h;
+}
+
+struct hostent *gethostbyname2(const char *, int) {
+	__ensure(!"gethostbyname2() not implemented");
+	__builtin_unreachable();
+}
+
+struct hostent *gethostbyaddr(const void *, socklen_t, int) {
+	__ensure(!"gethostbyaddr() not implemented");
+	__builtin_unreachable();
+}
+
+int gethostbyaddr_r(const void *__restrict, socklen_t, int, struct hostent *__restrict,
+					char *__restrict, size_t, struct hostent **__restrict, int *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int gethostbyname_r(const char *__restrict, struct hostent *__restrict, char *__restrict, size_t,
+					struct hostent **__restrict, int *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct protoent *getprotobyname(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct protoent *getprotobynumber(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct protoent *getprotoent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct servent *getservbyname(const char *name, const char *proto) {
+	int iproto = -1;
+	if (proto &&(!strncmp(proto, "tcp", 3) || !strncmp(proto, "TCP", 3)))
+		iproto = IPPROTO_TCP;
+	else if (proto && (!strncmp(proto, "udp", 3) || !strncmp(proto, "UDP", 3)))
+		iproto = IPPROTO_UDP;
+
+	static struct servent ret;
+	if (ret.s_name) {
+		free(ret.s_name);
+		ret.s_name = nullptr;
+
+		for (char **alias = ret.s_aliases; *alias != NULL; alias++) {
+			free(*alias);
+			*alias = nullptr;
+		}
+
+		free(ret.s_proto);
+		ret.s_proto = nullptr;
+	}
+
+	mlibc::service_result serv_buf{getAllocator()};
+	int count = mlibc::lookup_serv_by_name(serv_buf, name, iproto,
+			0, 0);
+	if (count <= 0)
+		return NULL;
+
+	ret.s_name = serv_buf[0].name.data();
+	serv_buf[0].name.detach();
+	// Sanity check.
+	if (strncmp(name, serv_buf[0].name.data(), serv_buf[0].name.size()))
+		return NULL;
+
+	ret.s_aliases = reinterpret_cast<char**>(malloc((serv_buf[0].aliases.size() + 1) * sizeof(char*)));
+	int alias_pos = 0;
+	for (auto &buf_name : serv_buf[0].aliases) {
+		ret.s_aliases[alias_pos] = buf_name.data();
+		buf_name.detach();
+		alias_pos++;
+	}
+	ret.s_aliases[alias_pos] = NULL;
+
+	ret.s_port = htons(serv_buf[0].port);
+
+	auto proto_string = frg::string<MemoryAllocator>(getAllocator());
+	if (!proto) {
+		if (serv_buf[0].protocol == IPPROTO_TCP)
+			proto_string = frg::string<MemoryAllocator>("tcp", getAllocator());
+		else if (serv_buf[0].protocol == IPPROTO_UDP)
+			proto_string = frg::string<MemoryAllocator>("udp", getAllocator());
+		else
+			return NULL;
+	} else {
+		proto_string = frg::string<MemoryAllocator>(proto, getAllocator());
+	}
+	ret.s_proto = proto_string.data();
+	proto_string.detach();
+
+	return &ret;
+}
+
+struct servent *getservbyport(int port, const char *proto) {
+	int iproto = -1;
+	if (proto && (!strncmp(proto, "tcp", 3) || !strncmp(proto, "TCP", 3)))
+		iproto = IPPROTO_TCP;
+	else if (proto && (!strncmp(proto, "udp", 3) || !strncmp(proto, "UDP", 3)))
+		iproto = IPPROTO_UDP;
+
+	static struct servent ret;
+	if (ret.s_name) {
+		free(ret.s_name);
+		ret.s_name = nullptr;
+
+		for (char **alias = ret.s_aliases; *alias != NULL; alias++) {
+			free(*alias);
+			*alias = nullptr;
+		}
+
+		free(ret.s_proto);
+		ret.s_proto = nullptr;
+	}
+
+	mlibc::service_result serv_buf{getAllocator()};
+	int count = mlibc::lookup_serv_by_port(serv_buf, iproto, ntohs(port));
+	if (count <= 0)
+		return NULL;
+
+	ret.s_name = serv_buf[0].name.data();
+	serv_buf[0].name.detach();
+
+	ret.s_aliases = reinterpret_cast<char**>(malloc((serv_buf[0].aliases.size() + 1) * sizeof(char*)));
+	int alias_pos = 0;
+	for (auto &buf_name : serv_buf[0].aliases) {
+		ret.s_aliases[alias_pos] = buf_name.data();
+		buf_name.detach();
+		alias_pos++;
+	}
+	ret.s_aliases[alias_pos] = NULL;
+
+	ret.s_port = port;
+
+	auto proto_string = frg::string<MemoryAllocator>(getAllocator());
+	if (!proto) {
+		if (serv_buf[0].protocol == IPPROTO_TCP)
+			proto_string = frg::string<MemoryAllocator>("tcp", getAllocator());
+		else if (serv_buf[0].protocol == IPPROTO_UDP)
+			proto_string = frg::string<MemoryAllocator>("udp", getAllocator());
+		else
+			return NULL;
+	} else {
+		proto_string = frg::string<MemoryAllocator>(proto, getAllocator());
+	}
+	ret.s_proto = proto_string.data();
+	proto_string.detach();
+
+	return &ret;
+}
+
+struct servent *getservent(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void sethostent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setnetent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setprotoent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setservent(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+const char *hstrerror(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/poll.cpp b/lib/mlibc/options/posix/generic/poll.cpp
new file mode 100644
index 0000000..c34e25e
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/poll.cpp
@@ -0,0 +1,31 @@
+
+#include <errno.h>
+#include <poll.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int poll(struct pollfd *fds, nfds_t count, int timeout) {
+	int num_events;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_poll, -1);
+	if(int e = mlibc::sys_poll(fds, count, timeout, &num_events); e) {
+		errno = e;
+		return -1;
+	}
+	return num_events;
+}
+
+#if __MLIBC_LINUX_OPTION
+int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *timeout_ts, const sigset_t *sigmask) {
+	sigset_t origmask;
+	int timeout = (timeout_ts == NULL) ? -1 : (timeout_ts->tv_sec * 1000 + timeout_ts->tv_nsec / 1000000);
+
+	sigprocmask(SIG_SETMASK, sigmask, &origmask);
+	int ready = poll(fds, nfds, timeout);
+	sigprocmask(SIG_SETMASK, &origmask, NULL);
+
+	return ready;
+}
+#endif // __MLIBC_LINUX_OPTION
+
diff --git a/lib/mlibc/options/posix/generic/posix-file-io.cpp b/lib/mlibc/options/posix/generic/posix-file-io.cpp
new file mode 100644
index 0000000..1a4f38b
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix-file-io.cpp
@@ -0,0 +1,275 @@
+#include <mlibc/posix-file-io.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+#include <errno.h>
+
+namespace mlibc {
+
+int mem_file::reopen(const char *, const char *) {
+	mlibc::panicLogger() << "mlibc: freopen() on a mem_file stream is unimplemented!" << frg::endlog;
+	return -1;
+}
+
+int mem_file::determine_type(stream_type *type) {
+	*type = stream_type::file_like;
+	return 0;
+}
+
+int mem_file::determine_bufmode(buffer_mode *mode) {
+	*mode = buffer_mode::no_buffer;
+	return 0;
+}
+
+memstream_mem_file::memstream_mem_file(char **ptr, size_t *sizeloc, int flags, void (*do_dispose)(abstract_file *))
+: mem_file{flags, do_dispose}, _bufloc{ptr}, _sizeloc{sizeloc} { }
+
+
+int memstream_mem_file::close() {
+	_update_ptrs();
+	_buf.detach();
+
+	return 0;
+}
+
+int memstream_mem_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if ((_pos >= 0 && _pos >= _max_size) || !max_size) {
+		*actual_size = 0;
+		return 0;
+	}
+
+	size_t bytes_read = std::min(size_t(_max_size - _pos), max_size);
+	memcpy(buffer, _buffer().data() + _pos, bytes_read);
+	_pos += bytes_read;
+	*actual_size = bytes_read;
+	return 0;
+}
+
+int memstream_mem_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	if (_pos + max_size >= _buffer_size()) {
+		_buf.resize(_pos + max_size + 1, '\0');
+		_update_ptrs();
+	}
+
+	size_t bytes_write = std::min(static_cast<size_t>(_buffer_size() - _pos), max_size);
+	memcpy(_buffer().data() + _pos, buffer, bytes_write);
+	_pos += max_size;
+	*actual_size = max_size;
+
+	return 0;
+}
+
+int memstream_mem_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	switch (whence) {
+		case SEEK_SET:
+			_pos = offset;
+			if (_pos >= 0 && size_t(_pos) >= _buffer_size()) {
+				_buf.resize(_pos + 1, '\0');
+				_update_ptrs();
+			}
+			*new_offset = _pos;
+			break;
+		case SEEK_CUR:
+			_pos += offset;
+			if (_pos >= 0 && size_t(_pos) >= _buffer_size()) {
+				_buf.resize(_pos + 1, '\0');
+				_update_ptrs();
+			}
+			*new_offset = _pos;
+			break;
+		case SEEK_END:
+			_pos = _buffer_size() ? _buffer_size() - 1 + offset : _buffer_size() + offset;
+			_buf.resize(_pos + 1, '\0');
+			_update_ptrs();
+			*new_offset = _pos;
+			break;
+		default:
+			return EINVAL;
+	}
+	return 0;
+}
+
+void memstream_mem_file::_update_ptrs() {
+	*_bufloc = _buf.data();
+	*_sizeloc = _buf.size() - 1;
+}
+
+fmemopen_mem_file::fmemopen_mem_file(void *in_buf, size_t size, int flags, void (*do_dispose)(abstract_file *))
+: mem_file{flags, do_dispose}, _inBuffer{in_buf}, _inBufferSize{size} {
+	if(!_inBuffer) {
+		_inBuffer = getAllocator().allocate(size);
+		_needsDeallocation = true;
+	}
+
+	if(_flags & O_APPEND) {
+		// the initial seek-size for append is zero if buf was NULL, or the first '\0' found, or the size
+		_max_size = (_needsDeallocation) ? 0 : strnlen(reinterpret_cast<char *>(_inBuffer), _inBufferSize);
+		_pos = _max_size;
+	} else if((_flags & O_WRONLY || _flags & O_RDWR) && _flags & O_CREAT && _flags & O_TRUNC) {
+		// modes: "w", "w+"
+		_max_size = 0;
+	} else {
+		_max_size = size;
+	}
+}
+
+int fmemopen_mem_file::close() {
+	if(_needsDeallocation) {
+		getAllocator().free(_inBuffer);
+	}
+
+	return 0;
+}
+
+int fmemopen_mem_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if ((_pos >= 0 && _pos >= _max_size) || !max_size) {
+		*actual_size = 0;
+		return 0;
+	}
+
+	size_t bytes_read = std::min(size_t(_max_size - _pos), max_size);
+	memcpy(buffer, _buffer().data() + _pos, bytes_read);
+	_pos += bytes_read;
+	*actual_size = bytes_read;
+	return 0;
+}
+
+int fmemopen_mem_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	off_t bytes_write = std::min(static_cast<size_t>(_buffer_size() - _pos), max_size);
+	memcpy(_buffer().data() + _pos, buffer, bytes_write);
+	_pos += bytes_write;
+	*actual_size = bytes_write;
+
+	if(_pos > _max_size) {
+		_max_size = _pos;
+	}
+
+	// upon flushing, we need to put a null byte at the current position or at the end of the buffer
+	size_t null = _pos;
+	// a special case is if the mode is set to updating ('+'), then it always goes at the end
+	if(null >= _buffer_size() || _flags & O_RDWR) {
+		null = _buffer_size() - 1;
+	}
+
+	if(_buffer_size()) {
+		_buffer()[null] = '\0';
+	}
+
+	return 0;
+}
+
+int fmemopen_mem_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	switch (whence) {
+		case SEEK_SET:
+			if(offset < 0 || size_t(offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos = offset;
+			*new_offset = _pos;
+			break;
+		case SEEK_CUR:
+			// seeking to negative positions or positions larger than the buffer is disallowed in fmemopen(3)
+			if((_pos + offset) < 0 || size_t(_pos + offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos += offset;
+			*new_offset = _pos;
+			break;
+		case SEEK_END:
+			if((_max_size + offset) < 0 || size_t(_max_size + offset) > _buffer_size()) {
+				return EINVAL;
+			}
+			_pos = _max_size + offset;
+			*new_offset = _pos;
+			break;
+		default:
+			return EINVAL;
+	}
+	return 0;
+}
+
+int cookie_file::close() {
+	if(!_funcs.close) {
+		return 0;
+	}
+
+	return _funcs.close(_cookie);
+}
+
+int cookie_file::reopen(const char *, const char *) {
+	mlibc::panicLogger() << "mlibc: freopen() on a cookie_file stream is unimplemented!" << frg::endlog;
+	return -1;
+}
+
+int cookie_file::determine_type(stream_type *type) {
+	*type = stream_type::file_like;
+	return 0;
+}
+
+int cookie_file::determine_bufmode(buffer_mode *mode) {
+	*mode = buffer_mode::no_buffer;
+	return 0;
+}
+
+int cookie_file::io_read(char *buffer, size_t max_size, size_t *actual_size) {
+	if(!_funcs.read) {
+		return EOF;
+	}
+
+	*actual_size = _funcs.read(_cookie, buffer, max_size);
+
+	return 0;
+}
+
+int cookie_file::io_write(const char *buffer, size_t max_size, size_t *actual_size) {
+	if(!_funcs.write) {
+		return 0;
+	}
+
+	*actual_size = _funcs.write(_cookie, buffer, max_size);
+
+	return 0;
+}
+
+int cookie_file::io_seek(off_t offset, int whence, off_t *new_offset) {
+	if(!_funcs.seek) {
+		return ENOTSUP;
+	}
+
+	*new_offset = offset;
+
+	return _funcs.seek(_cookie, new_offset, whence);
+}
+
+} // namespace mlibc
+
+FILE *fdopen(int fd, const char *mode) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	flags &= ~O_TRUNC; // 'w' should not truncate the file
+
+	if (flags & O_APPEND) {
+		int cur_flags = fcntl(fd, F_GETFL, 0);
+		if (cur_flags < 0) {
+			errno = EINVAL;
+			return nullptr;
+		} else if (!(cur_flags & O_APPEND)) {
+			if (fcntl(fd, F_SETFL, cur_flags | O_APPEND)) {
+				errno = EINVAL;
+				return nullptr;
+			}
+		}
+	}
+
+	if (flags & O_CLOEXEC) {
+		if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
+			errno = EINVAL;
+			return nullptr;
+		}
+	}
+
+	// TODO: We may need to activate line buffered mode for terminals.
+
+	return frg::construct<mlibc::fd_file>(getAllocator(), fd,
+			mlibc::file_dispose_cb<mlibc::fd_file>);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_ctype.cpp b/lib/mlibc/options/posix/generic/posix_ctype.cpp
new file mode 100644
index 0000000..19f129f
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_ctype.cpp
@@ -0,0 +1,136 @@
+#include <ctype.h>
+#include <wctype.h>
+
+#include <bits/ensure.h>
+
+int isalnum_l(int c, locale_t) {
+    return isalnum(c);
+}
+
+int isalpha_l(int c, locale_t) {
+    return isalpha(c);
+}
+
+int isblank_l(int c, locale_t) {
+    return isblank(c);
+}
+
+int iscntrl_l(int c, locale_t) {
+    return iscntrl(c);
+}
+
+int isdigit_l(int c, locale_t) {
+    return isdigit(c);
+}
+
+int isgraph_l(int c, locale_t) {
+    return isgraph(c);
+}
+
+int islower_l(int c, locale_t) {
+    return islower(c);
+}
+
+int isprint_l(int c, locale_t) {
+    return isprint(c);
+}
+
+int ispunct_l(int c, locale_t) {
+    return ispunct(c);
+}
+
+int isspace_l(int c, locale_t) {
+    return isspace(c);
+}
+
+int isupper_l(int c, locale_t) {
+    return isupper(c);
+}
+
+int isxdigit_l(int c, locale_t) {
+    return isxdigit(c);
+}
+
+int isascii_l(int c, locale_t) {
+    return isascii(c);
+}
+
+int tolower_l(int c, locale_t) {
+    return tolower(c);
+}
+
+int toupper_l(int c, locale_t) {
+    return toupper(c);
+}
+
+int iswalnum_l(wint_t c, locale_t) {
+    return iswalnum(c);
+}
+
+int iswblank_l(wint_t c, locale_t) {
+    return iswblank(c);
+}
+
+int iswcntrl_l(wint_t c, locale_t) {
+    return iswcntrl(c);
+}
+
+int iswdigit_l(wint_t c, locale_t) {
+    return iswdigit(c);
+}
+
+int iswgraph_l(wint_t c, locale_t) {
+    return iswgraph(c);
+}
+
+int iswlower_l(wint_t c, locale_t) {
+    return iswlower(c);
+}
+
+int iswprint_l(wint_t c, locale_t) {
+    return iswprint(c);
+}
+
+int iswpunct_l(wint_t c, locale_t) {
+    return iswpunct(c);
+}
+
+int iswspace_l(wint_t c, locale_t) {
+    return iswspace(c);
+}
+
+int iswupper_l(wint_t c, locale_t) {
+    return iswupper(c);
+}
+
+int iswxdigit_l(wint_t c, locale_t) {
+    return iswxdigit(c);
+}
+
+int iswalpha_l(wint_t c, locale_t) {
+    return iswalpha(c);
+}
+
+wctype_t wctype_l(const char* p, locale_t) {
+    return wctype(p);
+}
+
+int iswctype_l(wint_t w, wctype_t t, locale_t) {
+    return iswctype(w, t);
+}
+
+wint_t towlower_l(wint_t c, locale_t) {
+    return towlower(c);
+}
+
+wint_t towupper_l(wint_t c, locale_t) {
+    return towupper(c);
+}
+
+wctrans_t wctrans_l(const char* c, locale_t) {
+    return wctrans(c);
+}
+
+wint_t towctrans_l(wint_t c, wctrans_t desc, locale_t) {
+    return towctrans(c, desc);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_locale.cpp b/lib/mlibc/options/posix/generic/posix_locale.cpp
new file mode 100644
index 0000000..bd8710a
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_locale.cpp
@@ -0,0 +1,37 @@
+#include <bits/posix/posix_locale.h>
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+
+namespace {
+
+bool newlocale_seen = false;
+bool uselocale_seen = false;
+
+}
+
+locale_t newlocale(int, const char *, locale_t) {
+	// Due to all of the locale functions being stubs, the locale will not be used
+	if(!newlocale_seen) {
+		mlibc::infoLogger() << "mlibc: newlocale() is a no-op" << frg::endlog;
+		newlocale_seen = true;
+	}
+	return nullptr;
+}
+
+void freelocale(locale_t) {
+	mlibc::infoLogger() << "mlibc: freelocale() is a no-op" << frg::endlog;
+	return;
+}
+
+locale_t uselocale(locale_t) {
+	if(!uselocale_seen) {
+		mlibc::infoLogger() << "mlibc: uselocale() is a no-op" << frg::endlog;
+		uselocale_seen = true;
+	}
+	return nullptr;
+}
+
+locale_t duplocale(locale_t) {
+	mlibc::infoLogger() << "mlibc: duplocale() is a no-op" << frg::endlog;
+	return nullptr;
+}
diff --git a/lib/mlibc/options/posix/generic/posix_signal.cpp b/lib/mlibc/options/posix/generic/posix_signal.cpp
new file mode 100644
index 0000000..eef3ef3
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_signal.cpp
@@ -0,0 +1,151 @@
+
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+#include <bits/ensure.h>
+
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/tcb.hpp>
+
+int sigsuspend(const sigset_t *sigmask) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigsuspend, -1);
+
+	// This is guaranteed to return an error (EINTR most probably)
+	errno = mlibc::sys_sigsuspend(sigmask);
+	return -1;
+}
+
+int pthread_sigmask(int how, const sigset_t *__restrict set, sigset_t *__restrict retrieve) {
+	if(!mlibc::sys_sigprocmask) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+	if(int e = mlibc::sys_sigprocmask(how, set, retrieve); e) {
+		return e;
+	}
+	return 0;
+}
+
+int pthread_kill(pthread_t thread, int sig) {
+	auto tcb = reinterpret_cast<Tcb *>(thread);
+	auto pid = getpid();
+
+	if(!mlibc::sys_tgkill) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+
+	if(int e = mlibc::sys_tgkill(pid, tcb->tid, sig); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int sigaction(int signum, const struct sigaction *__restrict act, struct sigaction *__restrict oldact) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigaction, -1);
+	if(int e = mlibc::sys_sigaction(signum, act, oldact); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int siginterrupt(int sig, int flag) {
+	int ret;
+	struct sigaction act;
+
+	sigaction(sig, NULL, &act);
+	if (flag)
+		act.sa_flags &= ~SA_RESTART;
+	else
+		act.sa_flags |= SA_RESTART;
+
+	ret = sigaction(sig, &act, NULL);
+	return ret;
+}
+
+int kill(pid_t pid, int number) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_kill, -1);
+	if(int e = mlibc::sys_kill(pid, number); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int killpg(pid_t pgrp, int sig) {
+	if(pgrp > 1) {
+		return kill(-pgrp, sig);
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+int sigtimedwait(const sigset_t *__restrict set, siginfo_t *__restrict info, const struct timespec *__restrict timeout) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigtimedwait, -1);
+
+	int signo;
+
+	if (int e = sysdep(set, info, timeout, &signo)) {
+		errno = e;
+		return -1;
+	}
+
+	return signo;
+}
+
+int sigwaitinfo(const sigset_t *__restrict set, siginfo_t *__restrict info) {
+	// NOTE: This assumes the sysdep behavior noted in mlibc/posix-sysdeps.hpp
+	return sigtimedwait(set, info, nullptr);
+}
+
+int sigwait(const sigset_t *__restrict set, int *__restrict sig) {
+	if (int e = sigwaitinfo(set, nullptr); e < 0) {
+		return e;
+	} else {
+		if (sig)
+			*sig = e;
+
+		return 0;
+	}
+}
+
+int sigpending(sigset_t *set) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigpending, -1);
+
+	if(int e = sysdep(set)) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int sigaltstack(const stack_t *__restrict ss, stack_t *__restrict oss) {
+	if (ss && ss->ss_size < MINSIGSTKSZ && !(ss->ss_flags & SS_DISABLE)) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sigaltstack, -1);
+	if (int e = mlibc::sys_sigaltstack(ss, oss); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+#if __MLIBC_GLIBC_OPTION
+int sigisemptyset(const sigset_t *set) {
+	return !(*set);
+}
+#endif // __MLIBC_GLIBC_OPTION
+
+int sigqueue(pid_t, int, const union sigval) {
+	__ensure(!"sigqueue() not implemented");
+	__builtin_unreachable();
+}
+
diff --git a/lib/mlibc/options/posix/generic/posix_stdio.cpp b/lib/mlibc/options/posix/generic/posix_stdio.cpp
new file mode 100644
index 0000000..fc77a54
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_stdio.cpp
@@ -0,0 +1,209 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <bits/ensure.h>
+#include <mlibc/ansi-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/file-io.hpp>
+#include <mlibc/posix-file-io.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+struct popen_file : mlibc::fd_file {
+	popen_file(int fd, void (*do_dispose)(abstract_file *) = nullptr)
+		: fd_file(fd, do_dispose) {}
+
+	pid_t get_popen_pid() {
+		return _popen_pid;
+	}
+
+	void set_popen_pid(pid_t new_pid) {
+		_popen_pid = new_pid;
+	}
+
+private:
+	// Underlying PID in case of popen()
+	pid_t _popen_pid;
+};
+
+FILE *fmemopen(void *buf, size_t size, const char *__restrict mode) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	return frg::construct<mlibc::fmemopen_mem_file>(getAllocator(), buf, size, flags,
+		mlibc::file_dispose_cb<mlibc::mem_file>);
+}
+
+int pclose(FILE *stream) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitpid, -1);
+
+	auto file = static_cast<popen_file *>(stream);
+
+	int status;
+	pid_t pid = file->get_popen_pid();
+
+	fclose(file);
+
+	if (mlibc::sys_waitpid(pid, &status, 0, NULL, &pid) != 0) {
+	    errno = ECHILD;
+	    return -1;
+	}
+
+	return status;
+}
+
+FILE *popen(const char *command, const char *typestr) {
+	bool is_write;
+	pid_t child;
+	FILE *ret = nullptr;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fork && mlibc::sys_dup2 && mlibc::sys_execve &&
+			mlibc::sys_sigprocmask && mlibc::sys_sigaction && mlibc::sys_pipe, nullptr);
+
+	if (typestr == NULL) {
+		errno = EINVAL;
+		return nullptr;
+	}
+
+	if (strstr(typestr, "w") != NULL) {
+		is_write = true;
+	} else if (strstr(typestr, "r") != NULL) {
+		is_write = false;
+	} else {
+		errno = EINVAL;
+		return nullptr;
+	}
+
+	bool cloexec = false;
+	if (strstr(typestr, "e") != NULL) {
+		// Set FD_CLOEXEC on the new file descriptor
+		cloexec = true;
+	}
+
+	int fds[2];
+	if (int e = mlibc::sys_pipe(fds, 0)) {
+		errno = e;
+		return nullptr;
+	}
+
+	struct sigaction new_sa, old_int, old_quit;
+	sigset_t new_mask, old_mask;
+
+	new_sa.sa_handler = SIG_IGN;
+	new_sa.sa_flags = 0;
+	sigemptyset(&new_sa.sa_mask);
+	mlibc::sys_sigaction(SIGINT, &new_sa, &old_int);
+	mlibc::sys_sigaction(SIGQUIT, &new_sa, &old_quit);
+
+	sigemptyset(&new_mask);
+	sigaddset(&new_mask, SIGCHLD);
+	mlibc::sys_sigprocmask(SIG_BLOCK, &new_mask, &old_mask);
+
+	int parent_end = is_write ? 1 : 0;
+	int child_end = is_write ? 0 : 1;
+
+	if (int e = mlibc::sys_fork(&child)) {
+		errno = e;
+		mlibc::sys_close(fds[0]);
+		mlibc::sys_close(fds[1]);
+	} else if (!child) {
+		// For the child
+		mlibc::sys_sigaction(SIGINT, &old_int, nullptr);
+		mlibc::sys_sigaction(SIGQUIT, &old_quit, nullptr);
+		mlibc::sys_sigprocmask(SIG_SETMASK, &old_mask, nullptr);
+
+		mlibc::sys_close(fds[parent_end]);
+
+		if (mlibc::sys_dup2(fds[child_end], 0, is_write ? 0 : 1)) {
+			__ensure(!"sys_dup2() failed in popen()");
+		}
+		mlibc::sys_close(fds[child_end]);
+
+		const char *args[] = {
+			"sh", "-c", command, nullptr
+		};
+
+		mlibc::sys_execve("/bin/sh", const_cast<char **>(args), environ);
+		_Exit(127);
+	} else {
+		// For the parent
+		mlibc::sys_close(fds[child_end]);
+
+		ret = frg::construct<popen_file>(
+			getAllocator(),
+			fds[parent_end],
+			mlibc::file_dispose_cb<popen_file>
+		);
+		__ensure(ret);
+
+		auto file = static_cast<popen_file *>(ret);
+
+		file->set_popen_pid(child);
+
+		if (cloexec == true) {
+			fcntl(file->fd(), F_SETFD, O_CLOEXEC);
+		}
+	}
+
+	mlibc::sys_sigaction(SIGINT, &old_int, nullptr);
+	mlibc::sys_sigaction(SIGQUIT, &old_quit, nullptr);
+	mlibc::sys_sigprocmask(SIG_SETMASK, &old_mask, nullptr);
+
+	return ret;
+}
+
+FILE *open_memstream(char **buf, size_t *sizeloc) {
+	return frg::construct<mlibc::memstream_mem_file>(getAllocator(), buf, sizeloc, O_RDWR,
+			mlibc::file_dispose_cb<mlibc::mem_file>);
+}
+
+int fseeko(FILE *file_base, off_t offset, int whence) {
+	auto file = static_cast<mlibc::abstract_file *>(file_base);
+	if(int e = file->seek(offset, whence); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+off_t ftello(FILE *file_base) {
+	auto file = static_cast<mlibc::abstract_file *>(file_base);
+	off_t current_offset;
+	if(int e = file->tell(&current_offset); e) {
+		errno = e;
+		return -1;
+	}
+	return current_offset;
+}
+
+int dprintf(int fd, const char *format, ...) {
+	va_list args;
+	va_start(args, format);
+	int result = vdprintf(fd, format, args);
+	va_end(args);
+	return result;
+}
+
+int vdprintf(int fd, const char *format, __builtin_va_list args) {
+	mlibc::fd_file file{fd};
+	int ret = vfprintf(&file, format, args);
+	file.flush();
+	return ret;
+}
+
+char *fgetln(FILE *, size_t *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+FILE *fopencookie(void *cookie, const char *__restrict mode, cookie_io_functions_t funcs) {
+	int flags = mlibc::fd_file::parse_modestring(mode);
+
+	return frg::construct<mlibc::cookie_file>(getAllocator(), cookie, flags, funcs,
+		mlibc::file_dispose_cb<mlibc::cookie_file>);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_stdlib.cpp b/lib/mlibc/options/posix/generic/posix_stdlib.cpp
new file mode 100644
index 0000000..4010998
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_stdlib.cpp
@@ -0,0 +1,513 @@
+
+#include <abi-bits/fcntl.h>
+#include <bits/ensure.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+
+#include <frg/small_vector.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/rtdl-config.hpp>
+
+namespace {
+	constexpr bool debugPathResolution = false;
+}
+
+// Borrowed from musl
+static uint32_t init[] = {
+0x00000000,0x5851f42d,0xc0b18ccf,0xcbb5f646,
+0xc7033129,0x30705b04,0x20fd5db4,0x9a8b7f78,
+0x502959d8,0xab894868,0x6c0356a7,0x88cdb7ff,
+0xb477d43f,0x70a3a52b,0xa8e4baf1,0xfd8341fc,
+0x8ae16fd9,0x742d2f7a,0x0d1f0796,0x76035e09,
+0x40f7702c,0x6fa72ca5,0xaaa84157,0x58a0df74,
+0xc74a0364,0xae533cc4,0x04185faf,0x6de3b115,
+0x0cab8628,0xf043bfa4,0x398150e9,0x37521657};
+
+static int n = 31;
+static int i = 3;
+static int j = 0;
+static uint32_t *x = init + 1;
+
+
+static uint32_t lcg31(uint32_t x) {
+	return (1103515245 * x + 12345) & 0x7fffffff;
+}
+
+static uint64_t lcg64(uint64_t x) {
+	return 6364136223846793005ull * x + 1;
+}
+
+static void *savestate(void) {
+	x[-1] = (n << 16) | (i << 8) | j;
+	return x - 1;
+}
+
+static void loadstate(uint32_t *state) {
+	x = state + 1;
+	n = x[-1] >> 16;
+	i = (x[-1] >> 8) & 0xff;
+	j = x[-1] & 0xff;
+}
+
+long random(void) {
+	long k;
+
+	if(n == 0) {
+		k = x[0] = lcg31(x[0]);
+		return k;
+	}
+	x[i] += x[j];
+	k = x[i] >> 1;
+	if(++i == n)
+		i = 0;
+	if(++j == n)
+		j = 0;
+
+	return k;
+}
+
+double drand48(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void srand48(long int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// Borrowed from musl
+void srandom(unsigned int seed) {
+	int k;
+	uint64_t s = seed;
+
+	if(n == 0) {
+		x[0] = s;
+		return;
+	}
+	i = n == 31 || n == 7 ? 3 : 1;
+	j = 0;
+	for(k = 0; k < n; k++) {
+		s = lcg64(s);
+		x[k] = s >> 32;
+	}
+	// Make sure x contains at least one odd number
+	x[0] |= 1;
+}
+
+char *initstate(unsigned int seed, char *state, size_t size) {
+	void *old;
+
+	if(size < 8)
+		return 0;
+	old = savestate();
+	if(size < 32)
+		n = 0;
+	else if(size < 64)
+		n = 7;
+	else if(size < 128)
+		n = 15;
+	else if(size < 256)
+		n = 31;
+	else
+		n = 63;
+	x = (uint32_t *)state + 1;
+	srandom(seed);
+	savestate();
+	return (char *)old;
+}
+
+char *setstate(char *state) {
+	void *old;
+
+	old = savestate();
+	loadstate((uint32_t *)state);
+	return (char *)old;
+}
+
+// ----------------------------------------------------------------------------
+// Path handling.
+// ----------------------------------------------------------------------------
+
+
+int mkostemps(char *pattern, int suffixlen, int flags) {
+	auto n = strlen(pattern);
+	if(n < (6 + static_cast<size_t>(suffixlen))) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	flags &= ~O_WRONLY;
+
+	for(size_t i = 0; i < 6; i++) {
+		if(pattern[n - (6 + suffixlen) + i] == 'X')
+			continue;
+		errno = EINVAL;
+		return -1;
+	}
+
+	// TODO: Do an exponential search.
+	for(size_t i = 0; i < 999999; i++) {
+		char sfx = pattern[n - suffixlen];
+		__ensure(sprintf(pattern + (n - (6 + suffixlen)), "%06zu", i) == 6);
+		pattern[n - suffixlen] = sfx;
+
+		int fd;
+		if(int e = mlibc::sys_open(pattern, O_RDWR | O_CREAT | O_EXCL | flags, S_IRUSR | S_IWUSR, &fd); !e) {
+			return fd;
+		}else if(e != EEXIST) {
+			errno = e;
+			return -1;
+		}
+	}
+
+	errno = EEXIST;
+	return -1;
+}
+
+int mkostemp(char *pattern, int flags) {
+	return mkostemps(pattern, flags, 0);
+}
+
+int mkstemp(char *path) {
+	return mkostemp(path, 0);
+}
+
+int mkstemps(char *pattern, int suffixlen) {
+	return mkostemps(pattern, suffixlen, 0);
+}
+
+char *mkdtemp(char *pattern) {
+	mlibc::infoLogger() << "mlibc mkdtemp(" << pattern << ") called" << frg::endlog;
+	auto n = strlen(pattern);
+	__ensure(n >= 6);
+	if(n < 6) {
+		errno = EINVAL;
+		return NULL;
+	}
+	for(size_t i = 0; i < 6; i++) {
+		if(pattern[n - 6 + i] == 'X')
+			continue;
+		errno = EINVAL;
+		return NULL;
+	}
+
+	// TODO: Do an exponential search.
+	for(size_t i = 0; i < 999999; i++) {
+		__ensure(sprintf(pattern + (n - 6), "%06zu", i) == 6);
+		if(int e = mlibc::sys_mkdir(pattern, S_IRWXU); !e) {
+			return pattern;
+		}else if(e != EEXIST) {
+			errno = e;
+			return NULL;
+		}
+	}
+
+	errno = EEXIST;
+	return NULL;
+}
+
+char *realpath(const char *path, char *out) {
+	if(debugPathResolution)
+		mlibc::infoLogger() << "mlibc realpath(): Called on '" << path << "'" << frg::endlog;
+	frg::string_view path_view{path};
+
+	// In case of the root, the string only contains the null-terminator.
+	frg::small_vector<char, PATH_MAX, MemoryAllocator> resolv{getAllocator()};
+	size_t ps;
+
+	// If the path is relative, we have to preprend the working directory.
+	if(path[0] == '/') {
+		resolv.push_back(0);
+		ps = 1;
+	}else{
+		MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getcwd, nullptr);
+
+		// Try to getcwd() until the buffer is large enough.
+		resolv.resize(128);
+		while(true) {
+			int e = mlibc::sys_getcwd(resolv.data(), resolv.size());
+			if(e == ERANGE) {
+				resolv.resize(2 * resolv.size());
+			}else if(!e) {
+				break;
+			}else{
+				errno = e;
+				return nullptr;
+			}
+		}
+		frg::string_view cwd_view{resolv.data()};
+		if(cwd_view == "/") {
+			// Restore our invariant that we only store the null-terminator for the root.
+			resolv.resize(1);
+			resolv[0] = 0;
+		}else{
+			resolv.resize(cwd_view.size() + 1);
+		}
+		ps = 0;
+	}
+
+	// Contains unresolved links as a relative path compared to resolv.
+	frg::small_vector<char, PATH_MAX, MemoryAllocator> lnk{getAllocator()};
+	size_t ls = 0;
+
+	auto process_segment = [&] (frg::string_view s_view) -> int {
+		if(debugPathResolution)
+			mlibc::infoLogger() << "mlibc realpath(): resolv is '" << resolv.data() << "'"
+					<< ", segment is " << s_view.data()
+					<< ", size: " << s_view.size() << frg::endlog;
+
+		if(!s_view.size() || s_view == ".") {
+			// Keep resolv invariant.
+			return 0;
+		}else if(s_view == "..") {
+			// Remove a single segment from resolv.
+			if(resolv.size() > 1) {
+				auto slash = strrchr(resolv.data(), '/');
+				__ensure(slash); // We never remove the leading sla.
+				resolv.resize((slash - resolv.data()) + 1);
+				*slash = 0; // Replace the slash by a null-terminator.
+			}
+			return 0;
+		}
+
+		// Append the segment to resolv.
+		auto rsz = resolv.size();
+		resolv[rsz - 1] = '/'; // Replace null-terminator by a slash.
+		resolv.resize(rsz + s_view.size() + 1);
+		memcpy(resolv.data() + rsz, s_view.data(), s_view.size());
+		resolv[rsz + s_view.size()] = 0;
+
+		// stat() the path to (1) see if it exists and (2) see if it is a link.
+		if(!mlibc::sys_stat) {
+			MLIBC_MISSING_SYSDEP();
+			return ENOSYS;
+		}
+		if(debugPathResolution)
+			mlibc::infoLogger() << "mlibc realpath(): stat()ing '"
+					<< resolv.data() << "'" << frg::endlog;
+		struct stat st;
+		if(int e = mlibc::sys_stat(mlibc::fsfd_target::path,
+				-1, resolv.data(), AT_SYMLINK_NOFOLLOW, &st); e)
+			return e;
+
+		if(S_ISLNK(st.st_mode)) {
+			if(debugPathResolution) {
+				mlibc::infoLogger() << "mlibc realpath(): Encountered symlink '"
+					<< resolv.data() << "'" << frg::endlog;
+			}
+
+			if(!mlibc::sys_readlink) {
+				MLIBC_MISSING_SYSDEP();
+				return ENOSYS;
+			}
+
+			ssize_t sz = 0;
+			char path[512];
+
+			if (int e = mlibc::sys_readlink(resolv.data(), path, 512, &sz); e)
+				return e;
+
+			if(debugPathResolution) {
+				mlibc::infoLogger() << "mlibc realpath(): Symlink resolves to '"
+					<< frg::string_view{path, static_cast<size_t>(sz)} << "'" << frg::endlog;
+			}
+
+			if (path[0] == '/') {
+				// Absolute path, replace resolv
+				resolv.resize(sz);
+				strncpy(resolv.data(), path, sz - 1);
+				resolv.data()[sz - 1] = 0;
+
+				if(debugPathResolution) {
+					mlibc::infoLogger() << "mlibc realpath(): Symlink is absolute, resolv: '"
+						<< resolv.data() << "'" << frg::endlog;
+				}
+			} else {
+				// Relative path, revert changes to resolv, prepend to lnk
+				resolv.resize(rsz);
+				resolv[rsz - 1] = 0;
+
+				auto lsz = lnk.size();
+				lnk.resize((lsz - ls) + sz + 1);
+				memmove(lnk.data() + sz, lnk.data() + ls, lsz - ls);
+				memcpy(lnk.data(), path, sz);
+				lnk[(lsz - ls) + sz] = 0;
+
+				ls = 0;
+
+				if(debugPathResolution) {
+					mlibc::infoLogger() << "mlibc realpath(): Symlink is relative, resolv: '"
+						<< resolv.data() << "' lnk: '"
+						<< frg::string_view{lnk.data(), lnk.size()} << "'" << frg::endlog;
+				}
+			}
+		}
+
+		return 0;
+	};
+
+	// Each iteration of this outer loop consumes segment of the input path.
+	// This design avoids copying the input path into lnk;
+	// the latter could often involve additional allocations.
+	while(ps < path_view.size()) {
+		frg::string_view ps_view;
+		if(auto slash = strchr(path + ps, '/'); slash) {
+			ps_view = frg::string_view{path + ps, static_cast<size_t>(slash - (path + ps))};
+		}else{
+			ps_view = frg::string_view{path + ps, strlen(path) - ps};
+		}
+		ps += ps_view.size() + 1;
+
+		// Handle one segment from the input path.
+		if(int e = process_segment(ps_view); e) {
+			errno = e;
+			return nullptr;
+		}
+
+		// This inner loop consumes segments of lnk.
+		while(ls < lnk.size()) {
+			frg::string_view ls_view;
+			if(auto slash = strchr(lnk.data() + ls, '/'); slash) {
+				ls_view = frg::string_view{lnk.data() + ls, static_cast<size_t>(slash - (lnk.data() + ls))};
+			}else{
+				ls_view = frg::string_view{lnk.data() + ls, strlen(lnk.data()) - ls};
+			}
+			ls += ls_view.size() + 1;
+
+			// Handle one segment from the link
+			if(int e = process_segment(ls_view); e) {
+				errno = e;
+				return nullptr;
+			}
+		}
+
+		// All of lnk was consumed, reset it
+		lnk.resize(0);
+		ls = 0;
+	}
+
+	if(resolv.size() == 1) {
+		resolv.resize(0);
+		resolv.push_back('/');
+		resolv.push_back(0);
+	}
+
+	if(debugPathResolution)
+		mlibc::infoLogger() << "mlibc realpath(): Returns '" << resolv.data() << "'" << frg::endlog;
+
+	if(resolv.size() > PATH_MAX) {
+		errno = ENAMETOOLONG;
+		return nullptr;
+	}
+
+	if(!out)
+		out = reinterpret_cast<char *>(getAllocator().allocate(resolv.size()));
+	strcpy(out, resolv.data());
+	return out;
+}
+
+// ----------------------------------------------------------------------------
+// Pseudoterminals
+// ----------------------------------------------------------------------------
+
+int ptsname_r(int fd, char *buffer, size_t length) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ptsname, ENOSYS);
+
+	if(int e = sysdep(fd, buffer, length); e)
+		return e;
+
+	return 0;
+}
+
+char *ptsname(int fd) {
+	static char buffer[128];
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ptsname, NULL);
+
+	if(int e = sysdep(fd, buffer, 128); e) {
+		errno = e;
+		return NULL;
+	}
+
+	return buffer;
+}
+
+int posix_openpt(int flags) {
+	int fd;
+	if(int e = mlibc::sys_open("/dev/ptmx", flags, 0, &fd); e) {
+		errno = e;
+		return -1;
+	}
+
+	return fd;
+}
+
+int unlockpt(int fd) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_unlockpt, -1);
+
+	if(int e = sysdep(fd); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int grantpt(int) {
+	return 0;
+}
+
+double strtod_l(const char *__restrict__ nptr, char ** __restrict__ endptr, locale_t) {
+	mlibc::infoLogger() << "mlibc: strtod_l ignores locale!" << frg::endlog;
+	return strtod(nptr, endptr);
+}
+
+long double strtold_l(const char *__restrict__, char ** __restrict__, locale_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+float strtof_l(const char *__restrict__ nptr, char **__restrict__ endptr, locale_t) {
+	mlibc::infoLogger() << "mlibc: strtof_l ignores locales" << frg::endlog;
+	return strtof(nptr, endptr);
+}
+
+int strcoll_l(const char *, const char *, locale_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getloadavg(double *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+char *secure_getenv(const char *name) {
+	if (mlibc::rtdlConfig().secureRequired)
+		return NULL;
+	else
+		return getenv(name);
+}
+
+void *reallocarray(void *ptr, size_t m, size_t n) {
+	if(n && m > -1 / n) {
+		errno = ENOMEM;
+		return 0;
+	}
+
+	return realloc(ptr, m * n);
+}
+
+char *canonicalize_file_name(const char *name) {
+	return realpath(name, NULL);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_string.cpp b/lib/mlibc/options/posix/generic/posix_string.cpp
new file mode 100644
index 0000000..d0bc7b5
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_string.cpp
@@ -0,0 +1,174 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <bits/ensure.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <signal.h>
+
+#include <mlibc/debug.hpp>
+
+char *strdup(const char *string) {
+	auto num_bytes = strlen(string);
+
+	char *new_string = (char *)malloc(num_bytes + 1);
+	if(!new_string) // TODO: set errno
+		return nullptr;
+
+	memcpy(new_string, string, num_bytes);
+	new_string[num_bytes] = 0;
+	return new_string;
+}
+
+char *strndup(const char *string, size_t max_size) {
+	auto num_bytes = strnlen(string, max_size);
+	char *new_string = (char *)malloc(num_bytes + 1);
+	if(!new_string) // TODO: set errno
+		return nullptr;
+
+	memcpy(new_string, string, num_bytes);
+	new_string[num_bytes] = 0;
+	return new_string;
+}
+
+char *stpcpy(char *__restrict dest, const char *__restrict src) {
+	auto n = strlen(src);
+	memcpy(dest, src, n + 1);
+	return dest + n;
+}
+
+char *stpncpy(char *__restrict dest, const char *__restrict src, size_t n) {
+	size_t nulls, copied, srcLen = strlen(src);
+	if (n >= srcLen) {
+		nulls = n - srcLen;
+		copied = srcLen;
+	} else {
+		nulls = 0;
+		copied = n;
+	}
+
+	memcpy(dest, src, copied);
+	memset(dest + srcLen, 0, nulls);
+	return dest + n - nulls;
+}
+
+size_t strnlen(const char *s, size_t n) {
+	size_t len = 0;
+	while(len < n && s[len])
+		++len;
+	return len;
+}
+
+char *strsep(char **m, const char *del) {
+	__ensure(m);
+
+	auto tok = *m;
+	if(!tok)
+		return nullptr;
+
+	// Replace the following delimiter by a null-terminator.
+	// After this loop: *p is null iff we reached the end of the string.
+	auto p = tok;
+	while(*p && !strchr(del, *p))
+		p++;
+
+	if(*p) {
+		*p = 0;
+		*m = p + 1;
+	}else{
+		*m = nullptr;
+	}
+	return tok;
+}
+
+char *strsignal(int sig) {
+	#define CASE_FOR(sigconst) case sigconst: s = #sigconst; break;
+	const char *s;
+	switch(sig) {
+	CASE_FOR(SIGABRT)
+	CASE_FOR(SIGFPE)
+	CASE_FOR(SIGILL)
+	CASE_FOR(SIGINT)
+	CASE_FOR(SIGSEGV)
+	CASE_FOR(SIGTERM)
+	CASE_FOR(SIGPROF)
+	CASE_FOR(SIGIO)
+	CASE_FOR(SIGPWR)
+	CASE_FOR(SIGALRM)
+	CASE_FOR(SIGBUS)
+	CASE_FOR(SIGCHLD)
+	CASE_FOR(SIGCONT)
+	CASE_FOR(SIGHUP)
+	CASE_FOR(SIGKILL)
+	CASE_FOR(SIGPIPE)
+	CASE_FOR(SIGQUIT)
+	CASE_FOR(SIGSTOP)
+	CASE_FOR(SIGTSTP)
+	CASE_FOR(SIGTTIN)
+	CASE_FOR(SIGTTOU)
+	CASE_FOR(SIGUSR1)
+	CASE_FOR(SIGUSR2)
+	CASE_FOR(SIGSYS)
+	CASE_FOR(SIGTRAP)
+	CASE_FOR(SIGURG)
+	CASE_FOR(SIGVTALRM)
+	CASE_FOR(SIGXCPU)
+	CASE_FOR(SIGXFSZ)
+	CASE_FOR(SIGWINCH)
+	default:
+		mlibc::infoLogger() << "mlibc: Unknown signal number " << sig << frg::endlog;
+		s = "Unknown signal number";
+	}
+	return const_cast<char *>(s);
+}
+
+char *strcasestr(const char *s, const char *pattern) {
+	size_t plen = strlen(pattern);
+	const char *p = s;
+	while(*p) {
+		// Need strncasecmp() to avoid checking past the end of a successful match.
+		if(!strncasecmp(p, pattern, plen))
+			return const_cast<char *>(p);
+		++p;
+	}
+	return nullptr;
+}
+
+void *memccpy(void *__restrict, const void *__restrict, int, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// This implementation was taken from musl
+void *memrchr(const void *m, int c, size_t n) {
+	const unsigned char *s = (const unsigned char *)m;
+	c = (unsigned char)c;
+	while(n--) {
+		if(s[n] == c)
+			return (void *)(s + n);
+	}
+	return 0;
+}
+
+// BSD extensions.
+// Taken from musl
+size_t strlcpy(char *d, const char *s, size_t n) {
+	char *d0 = d;
+
+	if(!n--)
+		goto finish;
+	for(; n && (*d=*s); n--, s++, d++);
+	*d = 0;
+finish:
+	return d-d0 + strlen(s);
+}
+
+size_t strlcat(char *d, const char *s, size_t n) {
+	size_t l = strnlen(d, n);
+	if(l == n) {
+		return l + strlen(s);
+	}
+	return l + strlcpy(d + l, s, n - l);
+}
diff --git a/lib/mlibc/options/posix/generic/posix_time.cpp b/lib/mlibc/options/posix/generic/posix_time.cpp
new file mode 100644
index 0000000..d93ebbc
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/posix_time.cpp
@@ -0,0 +1,32 @@
+#include <bits/posix/posix_time.h>
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+#include <errno.h>
+
+int utimes(const char *filename, const struct timeval times[2]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	struct timespec time[2];
+	if(times == nullptr) {
+		time[0].tv_sec = UTIME_NOW;
+		time[0].tv_nsec = UTIME_NOW;
+		time[1].tv_sec = UTIME_NOW;
+		time[1].tv_nsec = UTIME_NOW;
+	} else {
+		time[0].tv_sec = times[0].tv_sec;
+		time[0].tv_nsec = times[0].tv_usec * 1000;
+		time[1].tv_sec = times[1].tv_sec;
+		time[1].tv_nsec = times[1].tv_usec * 1000;
+	}
+
+	if (int e = mlibc::sys_utimensat(AT_FDCWD, filename, time, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int futimes(int, const struct timeval[2]) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/pthread-stubs.cpp b/lib/mlibc/options/posix/generic/pthread-stubs.cpp
new file mode 100644
index 0000000..9720bc2
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/pthread-stubs.cpp
@@ -0,0 +1,1426 @@
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include <bits/ensure.h>
+#include <frg/allocation.hpp>
+#include <frg/array.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/thread.hpp>
+#include <mlibc/tcb.hpp>
+#include <mlibc/tid.hpp>
+#include <mlibc/threads.hpp>
+
+static bool enableTrace = false;
+
+struct ScopeTrace {
+	ScopeTrace(const char *file, int line, const char *function)
+	: _file(file), _line(line), _function(function) {
+		if(!enableTrace)
+			return;
+		mlibc::infoLogger() << "trace: Enter scope "
+				<< _file << ":" << _line << " (in function "
+				<< _function << ")" << frg::endlog;
+	}
+
+	~ScopeTrace() {
+		if(!enableTrace)
+			return;
+		mlibc::infoLogger() << "trace: Exit scope" << frg::endlog;
+	}
+
+private:
+	const char *_file;
+	int _line;
+	const char *_function;
+};
+
+#define SCOPE_TRACE() ScopeTrace(__FILE__, __LINE__, __FUNCTION__)
+
+static constexpr unsigned int mutexRecursive = 1;
+static constexpr unsigned int mutexErrorCheck = 2;
+
+// TODO: either use uint32_t or determine the bit based on sizeof(int).
+static constexpr unsigned int mutex_owner_mask = (static_cast<uint32_t>(1) << 30) - 1;
+static constexpr unsigned int mutex_waiters_bit = static_cast<uint32_t>(1) << 31;
+
+// Only valid for the internal __mlibc_m mutex of wrlocks.
+static constexpr unsigned int mutex_excl_bit = static_cast<uint32_t>(1) << 30;
+
+static constexpr unsigned int rc_count_mask = (static_cast<uint32_t>(1) << 31) - 1;
+static constexpr unsigned int rc_waiters_bit = static_cast<uint32_t>(1) << 31;
+
+static constexpr size_t default_stacksize = 0x200000;
+static constexpr size_t default_guardsize = 4096;
+
+// ----------------------------------------------------------------------------
+// pthread_attr and pthread functions.
+// ----------------------------------------------------------------------------
+
+// pthread_attr functions.
+int pthread_attr_init(pthread_attr_t *attr) {
+	*attr = pthread_attr_t{};
+	attr->__mlibc_stacksize = default_stacksize;
+	attr->__mlibc_guardsize = default_guardsize;
+	attr->__mlibc_detachstate = PTHREAD_CREATE_JOINABLE;
+	return 0;
+}
+
+int pthread_attr_destroy(pthread_attr_t *) {
+	return 0;
+}
+
+int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate) {
+	*detachstate = attr->__mlibc_detachstate;
+	return 0;
+}
+int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate) {
+	if (detachstate != PTHREAD_CREATE_DETACHED &&
+			detachstate != PTHREAD_CREATE_JOINABLE)
+		return EINVAL;
+
+	attr->__mlibc_detachstate = detachstate;
+	return 0;
+}
+
+int pthread_attr_getstacksize(const pthread_attr_t *__restrict attr, size_t *__restrict stacksize) {
+	*stacksize = attr->__mlibc_stacksize;
+	return 0;
+}
+
+int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize) {
+	if (stacksize < PTHREAD_STACK_MIN)
+		return EINVAL;
+	attr->__mlibc_stacksize = stacksize;
+	return 0;
+}
+
+int pthread_attr_getstackaddr(const pthread_attr_t *attr, void **stackaddr) {
+	*stackaddr = attr->__mlibc_stackaddr;
+	return 0;
+}
+int pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr) {
+	attr->__mlibc_stackaddr = stackaddr;
+	return 0;
+}
+
+int pthread_attr_getstack(const pthread_attr_t *attr, void **stackaddr, size_t *stacksize) {
+	*stackaddr = attr->__mlibc_stackaddr;
+	*stacksize = attr->__mlibc_stacksize;
+	return 0;
+}
+int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr, size_t stacksize) {
+	if (stacksize < PTHREAD_STACK_MIN)
+		return EINVAL;
+	attr->__mlibc_stacksize = stacksize;
+	attr->__mlibc_stackaddr = stackaddr;
+	return 0;
+}
+
+int pthread_attr_getguardsize(const pthread_attr_t *__restrict attr, size_t *__restrict guardsize) {
+	*guardsize = attr->__mlibc_guardsize;
+	return 0;
+}
+int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize) {
+	attr->__mlibc_guardsize = guardsize;
+	return 0;
+}
+
+int pthread_attr_getscope(const pthread_attr_t *attr, int *scope) {
+	*scope = attr->__mlibc_scope;
+	return 0;
+}
+int pthread_attr_setscope(pthread_attr_t *attr, int scope) {
+	if (scope != PTHREAD_SCOPE_SYSTEM &&
+			scope != PTHREAD_SCOPE_PROCESS)
+		return EINVAL;
+	if (scope == PTHREAD_SCOPE_PROCESS)
+		return ENOTSUP;
+	attr->__mlibc_scope = scope;
+	return 0;
+}
+
+int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inheritsched) {
+	*inheritsched = attr->__mlibc_inheritsched;
+	return 0;
+}
+int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched) {
+	if (inheritsched != PTHREAD_INHERIT_SCHED &&
+			inheritsched != PTHREAD_EXPLICIT_SCHED)
+		return EINVAL;
+	attr->__mlibc_inheritsched = inheritsched;
+	return 0;
+}
+
+int pthread_attr_getschedparam(const pthread_attr_t *__restrict attr, struct sched_param *__restrict schedparam) {
+	*schedparam = attr->__mlibc_schedparam;
+	return 0;
+}
+int pthread_attr_setschedparam(pthread_attr_t *__restrict attr, const struct sched_param *__restrict schedparam) {
+	// TODO: this is supposed to return EINVAL for when the schedparam doesn't make sense
+	// for the given schedpolicy.
+	attr->__mlibc_schedparam = *schedparam;
+	return 0;
+}
+
+int pthread_attr_getschedpolicy(const pthread_attr_t *__restrict attr, int *__restrict policy) {
+	*policy = attr->__mlibc_schedpolicy;
+	return 0;
+}
+int pthread_attr_setschedpolicy(pthread_attr_t *__restrict attr, int policy) {
+	if (policy != SCHED_FIFO && policy != SCHED_RR &&
+			policy != SCHED_OTHER)
+		return EINVAL;
+	attr->__mlibc_schedpolicy = policy;
+	return 0;
+}
+
+#if __MLIBC_LINUX_OPTION
+int pthread_attr_getaffinity_np(const pthread_attr_t *__restrict attr,
+		size_t cpusetsize, cpu_set_t *__restrict cpusetp) {
+	if (!attr)
+		return EINVAL;
+
+	if (!attr->__mlibc_cpuset) {
+		memset(cpusetp, -1, cpusetsize);
+		return 0;
+	}
+
+	for (size_t cnt = cpusetsize; cnt < attr->__mlibc_cpusetsize; cnt++)
+		if (reinterpret_cast<char*>(attr->__mlibc_cpuset)[cnt] != '\0')
+			return ERANGE;
+
+	auto p = memcpy(cpusetp, attr->__mlibc_cpuset,
+			std::min(cpusetsize, attr->__mlibc_cpusetsize));
+	if (cpusetsize > attr->__mlibc_cpusetsize)
+		memset(p, '\0', cpusetsize - attr->__mlibc_cpusetsize);
+
+	return 0;
+}
+
+int pthread_attr_setaffinity_np(pthread_attr_t *__restrict attr,
+		size_t cpusetsize, const cpu_set_t *__restrict cpusetp) {
+	if (!attr)
+		return EINVAL;
+
+	if (!cpusetp || !cpusetsize) {
+		attr->__mlibc_cpuset = NULL;
+		attr->__mlibc_cpusetsize = 0;
+		return 0;
+	}
+
+	if (attr->__mlibc_cpusetsize != cpusetsize) {
+		auto newp = realloc(attr->__mlibc_cpuset, cpusetsize);
+		if (!newp)
+			return ENOMEM;
+
+		attr->__mlibc_cpuset = static_cast<cpu_set_t*>(newp);
+		attr->__mlibc_cpusetsize = cpusetsize;
+	}
+
+	memcpy(attr->__mlibc_cpuset, cpusetp, cpusetsize);
+	return 0;
+}
+
+int pthread_attr_getsigmask_np(const pthread_attr_t *__restrict attr,
+		sigset_t *__restrict sigmask) {
+	if (!attr)
+		return EINVAL;
+
+	if (!attr->__mlibc_sigmaskset) {
+		sigemptyset(sigmask);
+		return PTHREAD_ATTR_NO_SIGMASK_NP;
+	}
+
+	*sigmask = attr->__mlibc_sigmask;
+
+	return 0;
+}
+int pthread_attr_setsigmask_np(pthread_attr_t *__restrict attr,
+		const sigset_t *__restrict sigmask) {
+	if (!attr)
+		return EINVAL;
+
+	if (!sigmask) {
+		attr->__mlibc_sigmaskset = 0;
+		return 0;
+	}
+
+	attr->__mlibc_sigmask = *sigmask;
+	attr->__mlibc_sigmaskset = 1;
+
+	// Filter out internally used signals.
+	sigdelset(&attr->__mlibc_sigmask, SIGCANCEL);
+
+	return 0;
+}
+
+namespace {
+	void get_own_stackinfo(void **stack_addr, size_t *stack_size) {
+		auto fp = fopen("/proc/self/maps", "r");
+		if (!fp) {
+			mlibc::infoLogger() << "mlibc pthreads: /proc/self/maps does not exist! Producing incorrect"
+				" stack results!" << frg::endlog;
+			return;
+		}
+
+		char line[256];
+		auto sp = mlibc::get_sp();
+		while (fgets(line, 256, fp)) {
+			uintptr_t from, to;
+			if(sscanf(line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) != 2)
+				continue;
+			if (sp < to && sp > from) {
+				// We need to return the lowest byte of the stack.
+				*stack_addr = reinterpret_cast<void*>(from);
+				*stack_size = to - from;
+				fclose(fp);
+				return;
+			}
+		}
+
+		fclose(fp);
+	}
+}
+
+int pthread_getattr_np(pthread_t thread, pthread_attr_t *attr) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+	*attr = pthread_attr_t{};
+
+	if (!tcb->stackAddr || !tcb->stackSize) {
+		get_own_stackinfo(&attr->__mlibc_stackaddr, &attr->__mlibc_stacksize);
+	} else {
+		attr->__mlibc_stacksize = tcb->stackSize;
+		attr->__mlibc_stackaddr = tcb->stackAddr;
+	}
+
+	attr->__mlibc_guardsize = tcb->guardSize;
+	attr->__mlibc_detachstate = tcb->isJoinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED;
+	mlibc::infoLogger() << "pthread_getattr_np(): Implementation is incomplete!" << frg::endlog;
+	return 0;
+}
+
+int pthread_getaffinity_np(pthread_t thread, size_t cpusetsize, cpu_set_t *mask) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getthreadaffinity, ENOSYS);
+	return mlibc::sys_getthreadaffinity(reinterpret_cast<Tcb*>(thread)->tid, cpusetsize, mask);
+}
+
+int pthread_setaffinity_np(pthread_t thread, size_t cpusetsize, const cpu_set_t *mask) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setthreadaffinity, ENOSYS);
+	return mlibc::sys_setthreadaffinity(reinterpret_cast<Tcb*>(thread)->tid, cpusetsize, mask);
+}
+#endif // __MLIBC_LINUX_OPTION
+
+extern "C" Tcb *__rtdl_allocateTcb();
+
+// pthread functions.
+int pthread_create(pthread_t *__restrict thread, const pthread_attr_t *__restrict attrp,
+		void *(*entry) (void *), void *__restrict user_arg) {
+	return mlibc::thread_create(thread, attrp, reinterpret_cast<void *>(entry), user_arg, false);
+}
+
+pthread_t pthread_self(void) {
+	return reinterpret_cast<pthread_t>(mlibc::get_current_tcb());
+}
+
+int pthread_equal(pthread_t t1, pthread_t t2) {
+	if(t1 == t2)
+		return 1;
+	return 0;
+}
+
+namespace {
+	struct key_global_info {
+		bool in_use;
+
+		void (*dtor)(void *);
+		uint64_t generation;
+	};
+
+	constinit frg::array<
+		key_global_info,
+		PTHREAD_KEYS_MAX
+	> key_globals_{};
+
+	FutexLock key_mutex_;
+}
+
+namespace mlibc {
+	__attribute__ ((__noreturn__)) void do_exit() {
+		sys_thread_exit();
+		__builtin_unreachable();
+	}
+}
+
+__attribute__ ((__noreturn__)) void pthread_exit(void *ret_val) {
+	auto self = mlibc::get_current_tcb();
+
+	if (__atomic_load_n(&self->cancelBits, __ATOMIC_RELAXED) & tcbExitingBit)
+		mlibc::do_exit();
+
+	__atomic_fetch_or(&self->cancelBits, tcbExitingBit, __ATOMIC_RELAXED);
+
+	auto hand = self->cleanupEnd;
+	while (hand) {
+		auto old = hand;
+		hand->func(hand->arg);
+		hand = hand->prev;
+		frg::destruct(getAllocator(), old);
+	}
+
+	for (size_t j = 0; j < PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
+		for (size_t i = 0; i < PTHREAD_KEYS_MAX; i++) {
+			if (auto v = pthread_getspecific(i)) {
+				key_mutex_.lock();
+				auto dtor = key_globals_[i].dtor;
+				key_mutex_.unlock();
+
+				if (dtor) {
+					dtor(v);
+					(*self->localKeys)[i].value = nullptr;
+				}
+			}
+		}
+	}
+
+	self->returnValue.voidPtr = ret_val;
+	__atomic_store_n(&self->didExit, 1, __ATOMIC_RELEASE);
+	mlibc::sys_futex_wake(&self->didExit);
+
+	// TODO: clean up thread resources when we are detached.
+
+	// TODO: do exit(0) when we're the only thread instead
+	mlibc::do_exit();
+}
+
+int pthread_join(pthread_t thread, void **ret) {
+	return mlibc::thread_join(thread, ret);
+}
+
+int pthread_detach(pthread_t thread) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+	if (!__atomic_load_n(&tcb->isJoinable, __ATOMIC_RELAXED))
+		return EINVAL;
+
+	int expected = 1;
+	if(!__atomic_compare_exchange_n(&tcb->isJoinable, &expected, 0, false, __ATOMIC_RELEASE,
+				__ATOMIC_RELAXED))
+		return EINVAL;
+
+	return 0;
+}
+
+void pthread_cleanup_push(void (*func) (void *), void *arg) {
+	auto self = mlibc::get_current_tcb();
+
+	auto hand = frg::construct<Tcb::CleanupHandler>(getAllocator());
+	hand->func = func;
+	hand->arg = arg;
+	hand->next = nullptr;
+	hand->prev = self->cleanupEnd;
+
+	if (self->cleanupEnd)
+		self->cleanupEnd->next = hand;
+
+	self->cleanupEnd = hand;
+
+	if (!self->cleanupBegin)
+		self->cleanupBegin = self->cleanupEnd;
+}
+
+void pthread_cleanup_pop(int execute) {
+	auto self = mlibc::get_current_tcb();
+
+	auto hand = self->cleanupEnd;
+
+	if (self->cleanupEnd)
+		self->cleanupEnd = self->cleanupEnd->prev;
+	if (self->cleanupEnd)
+		self->cleanupEnd->next = nullptr;
+
+	if (execute)
+		hand->func(hand->arg);
+
+	frg::destruct(getAllocator(), hand);
+}
+
+int pthread_setname_np(pthread_t thread, const char *name) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_thread_setname, ENOSYS);
+	if(int e = sysdep(tcb, name); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int pthread_getname_np(pthread_t thread, char *name, size_t size) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_thread_getname, ENOSYS);
+	if(int e = sysdep(tcb, name, size); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int pthread_setschedparam(pthread_t thread, int policy, const struct sched_param *param) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setschedparam, ENOSYS);
+	if(int e = mlibc::sys_setschedparam(tcb, policy, param); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+int pthread_getschedparam(pthread_t thread, int *policy, struct sched_param *param) {
+	auto tcb = reinterpret_cast<Tcb*>(thread);
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getschedparam, ENOSYS);
+	if(int e = mlibc::sys_getschedparam(tcb, policy, param); e) {
+		return e;
+	}
+
+	return 0;
+}
+
+//pthread cancel functions
+
+extern "C" void __mlibc_do_cancel() {
+	//TODO(geert): for now the same as pthread_exit()
+	pthread_exit(PTHREAD_CANCELED);
+}
+
+namespace {
+
+	void sigcancel_handler(int signal, siginfo_t *info, void *ucontext) {
+		ucontext_t *uctx = static_cast<ucontext_t*>(ucontext);
+		// The function could be called from other signals, or from another
+		// process, in which case we should do nothing.
+		if (signal != SIGCANCEL || info->si_pid != getpid() ||
+				info->si_code != SI_TKILL)
+			return;
+
+		auto tcb = reinterpret_cast<Tcb*>(mlibc::get_current_tcb());
+		int old_value = tcb->cancelBits;
+
+		/*
+		 * When a thread is marked with deferred cancellation and performs a blocking syscall,
+		 * the spec mandates that the syscall can get interrupted before it has caused any side
+		 * effects (e.g. before a read() has read any bytes from disk). If the syscall has
+		 * already caused side effects it should return its partial work, and set the program
+		 * counter just after the syscall. If the syscall hasn't caused any side effects, it
+		 * should fail with EINTR and set the program counter to the syscall instruction.
+		 *
+		 *	cancellable_syscall:
+		 *		test whether_a_cancel_is_queued
+		 *		je cancel
+		 *		syscall
+		 *	end_cancellable_syscall
+		 *
+		 * The mlibc::sys_before_cancellable_syscall sysdep should return 1 when the
+		 * program counter is between the 'canellable_syscall' and 'end_cancellable_syscall' label.
+		 */
+		if (!(old_value & tcbCancelAsyncBit) &&
+				mlibc::sys_before_cancellable_syscall && !mlibc::sys_before_cancellable_syscall(uctx))
+			return;
+
+		int bitmask = tcbCancelTriggerBit | tcbCancelingBit;
+		while (1) {
+			int new_value = old_value | bitmask;
+
+			// Check if we are already cancelled or exiting
+			if (old_value == new_value || old_value & tcbExitingBit)
+				return;
+
+			int current_value = old_value;
+			if (__atomic_compare_exchange_n(&tcb->cancelBits, &current_value,
+						new_value, true,__ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+				tcb->returnValue.voidPtr = PTHREAD_CANCELED;
+
+				// Perform cancellation
+				__mlibc_do_cancel();
+
+				break;
+			}
+
+			old_value = current_value;
+		}
+	}
+}
+
+namespace mlibc {
+namespace {
+
+struct PthreadSignalInstaller {
+	PthreadSignalInstaller() {
+		struct sigaction sa;
+		sa.sa_sigaction = sigcancel_handler;
+		sa.sa_flags = SA_SIGINFO;
+		auto e = ENOSYS;
+		if(sys_sigaction)
+			e = sys_sigaction(SIGCANCEL, &sa, NULL);
+		// Opt-out of cancellation support.
+		if(e == ENOSYS)
+			return;
+		__ensure(!e);
+	}
+};
+
+PthreadSignalInstaller pthread_signal_installer;
+
+} // anonymous namespace
+} // namespace mlibc
+
+int pthread_setcanceltype(int type, int *oldtype) {
+	if (type != PTHREAD_CANCEL_DEFERRED && type != PTHREAD_CANCEL_ASYNCHRONOUS)
+		return EINVAL;
+
+	auto self = reinterpret_cast<Tcb *>(mlibc::get_current_tcb());
+	int old_value = self->cancelBits;
+	while (1) {
+		int new_value = old_value & ~tcbCancelAsyncBit;
+		if (type == PTHREAD_CANCEL_ASYNCHRONOUS)
+			new_value |= tcbCancelAsyncBit;
+
+		if (oldtype)
+			*oldtype = ((old_value & tcbCancelAsyncBit)
+					? PTHREAD_CANCEL_ASYNCHRONOUS
+					: PTHREAD_CANCEL_DEFERRED);
+
+		// Avoid unecessary atomic op.
+		if (old_value == new_value)
+			break;
+
+		int current_value = old_value;
+		if (__atomic_compare_exchange_n(&self->cancelBits, &current_value,
+					new_value, true, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+
+			if (mlibc::tcb_async_cancelled(new_value))
+				__mlibc_do_cancel();
+
+			break;
+		}
+
+		old_value = current_value;
+	}
+
+	return 0;
+}
+int pthread_setcancelstate(int state, int *oldstate) {
+	if (state != PTHREAD_CANCEL_ENABLE && state != PTHREAD_CANCEL_DISABLE)
+		return EINVAL;
+
+	auto self = reinterpret_cast<Tcb *>(mlibc::get_current_tcb());
+	int old_value = self->cancelBits;
+	while (1) {
+		int new_value = old_value & ~tcbCancelEnableBit;
+		if (state == PTHREAD_CANCEL_ENABLE)
+			new_value |= tcbCancelEnableBit;
+
+		if (oldstate)
+			*oldstate = ((old_value & tcbCancelEnableBit)
+					? PTHREAD_CANCEL_ENABLE
+					: PTHREAD_CANCEL_DISABLE);
+
+		// Avoid unecessary atomic op.
+		if (old_value == new_value)
+			break;
+
+		int current_value = old_value;
+		if (__atomic_compare_exchange_n(&self->cancelBits, &current_value,
+					new_value, true, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+
+			if (mlibc::tcb_async_cancelled(new_value))
+				__mlibc_do_cancel();
+
+			sigset_t set = {};
+			sigaddset(&set, SIGCANCEL);
+			if (new_value & PTHREAD_CANCEL_ENABLE)
+				sigprocmask(SIG_UNBLOCK, &set, NULL);
+			else
+				sigprocmask(SIG_BLOCK, &set, NULL);
+			break;
+		}
+
+		old_value = current_value;
+	}
+
+	return 0;
+}
+void pthread_testcancel(void) {
+	auto self = reinterpret_cast<Tcb *>(mlibc::get_current_tcb());
+	int value = self->cancelBits;
+	if ((value & tcbCancelEnableBit) && (value & tcbCancelTriggerBit)) {
+		__mlibc_do_cancel();
+		__builtin_unreachable();
+	}
+}
+int pthread_cancel(pthread_t thread) {
+	if (!mlibc::sys_tgkill) {
+		MLIBC_MISSING_SYSDEP();
+		return ENOSYS;
+	}
+
+	auto tcb = reinterpret_cast<Tcb *>(thread);
+	// Check if the TCB is valid, somewhat..
+	if (tcb->selfPointer != tcb)
+		return ESRCH;
+
+	int old_value = __atomic_load_n(&tcb->cancelBits, __ATOMIC_RELAXED);
+	while (1) {
+		int bitmask = tcbCancelTriggerBit;
+
+		int new_value = old_value | bitmask;
+		if (old_value == new_value)
+			break;
+
+		int current_value = old_value;
+		if (__atomic_compare_exchange_n(&tcb->cancelBits, &current_value,
+					new_value, true, __ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
+			if (mlibc::tcb_cancel_enabled(new_value)) {
+				pid_t pid = getpid();
+
+				int res = mlibc::sys_tgkill(pid, tcb->tid, SIGCANCEL);
+
+				current_value = __atomic_load_n(&tcb->cancelBits, __ATOMIC_RELAXED);
+
+				// If we can't find the thread anymore, it's possible that it exited between
+				// us setting the cancel trigger bit, and us sending the signal. Check the
+				// cancelBits for tcbExitingBit to confirm that.
+				// XXX(qookie): This will be an use-after-free once we start freeing TCBs on
+				//              exit. Perhaps the TCB should be refcounted.
+				if (!(res == ESRCH && (current_value & tcbExitingBit)))
+					return res;
+			}
+
+			break;
+		}
+
+		old_value = current_value;
+	}
+
+	return 0;
+}
+
+int pthread_atfork(void (*prepare) (void), void (*parent) (void), void (*child) (void)) {
+	auto self = mlibc::get_current_tcb();
+
+	auto hand = frg::construct<Tcb::AtforkHandler>(getAllocator());
+	if (!hand)
+		return -1;
+
+	hand->prepare = prepare;
+	hand->parent = parent;
+	hand->child = child;
+	hand->next = nullptr;
+	hand->prev = self->atforkEnd;
+
+	if (self->atforkEnd)
+		self->atforkEnd->next = hand;
+
+	self->atforkEnd = hand;
+
+	if (!self->atforkBegin)
+		self->atforkBegin = self->atforkEnd;
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+// pthread_key functions.
+// ----------------------------------------------------------------------------
+
+int pthread_key_create(pthread_key_t *out, void (*destructor)(void *)) {
+	SCOPE_TRACE();
+
+	auto g = frg::guard(&key_mutex_);
+
+	pthread_key_t key = PTHREAD_KEYS_MAX;
+	for (size_t i = 0; i < PTHREAD_KEYS_MAX; i++) {
+		if (!key_globals_[i].in_use) {
+			key = i;
+			break;
+		}
+	}
+
+	if (key == PTHREAD_KEYS_MAX)
+		return EAGAIN;
+
+	key_globals_[key].in_use = true;
+	key_globals_[key].dtor = destructor;
+
+	*out = key;
+
+	return 0;
+}
+
+int pthread_key_delete(pthread_key_t key) {
+	SCOPE_TRACE();
+
+	auto g = frg::guard(&key_mutex_);
+
+	if (key >= PTHREAD_KEYS_MAX || !key_globals_[key].in_use)
+		return EINVAL;
+
+	key_globals_[key].in_use = false;
+	key_globals_[key].dtor = nullptr;
+	key_globals_[key].generation++;
+
+	return 0;
+}
+
+void *pthread_getspecific(pthread_key_t key) {
+	SCOPE_TRACE();
+
+	auto self = mlibc::get_current_tcb();
+	auto g = frg::guard(&key_mutex_);
+
+	if (key >= PTHREAD_KEYS_MAX || !key_globals_[key].in_use)
+		return nullptr;
+
+	if (key_globals_[key].generation > (*self->localKeys)[key].generation) {
+		(*self->localKeys)[key].value = nullptr;
+		(*self->localKeys)[key].generation = key_globals_[key].generation;
+	}
+
+	return (*self->localKeys)[key].value;
+}
+
+int pthread_setspecific(pthread_key_t key, const void *value) {
+	SCOPE_TRACE();
+
+	auto self = mlibc::get_current_tcb();
+	auto g = frg::guard(&key_mutex_);
+
+	if (key >= PTHREAD_KEYS_MAX || !key_globals_[key].in_use)
+		return EINVAL;
+
+	(*self->localKeys)[key].value = const_cast<void *>(value);
+	(*self->localKeys)[key].generation = key_globals_[key].generation;
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+// pthread_once functions.
+// ----------------------------------------------------------------------------
+
+static constexpr unsigned int onceComplete = 1;
+static constexpr unsigned int onceLocked = 2;
+
+int pthread_once(pthread_once_t *once, void (*function) (void)) {
+	SCOPE_TRACE();
+
+	auto expected = __atomic_load_n(&once->__mlibc_done, __ATOMIC_ACQUIRE);
+
+	// fast path: the function was already run.
+	while(!(expected & onceComplete)) {
+		if(!expected) {
+			// try to acquire the mutex.
+			if(!__atomic_compare_exchange_n(&once->__mlibc_done,
+					&expected, onceLocked, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE))
+				continue;
+
+			function();
+
+			// unlock the mutex.
+			__atomic_exchange_n(&once->__mlibc_done, onceComplete, __ATOMIC_RELEASE);
+			if(int e = mlibc::sys_futex_wake((int *)&once->__mlibc_done); e)
+				__ensure(!"sys_futex_wake() failed");
+			return 0;
+		}else{
+			// a different thread is currently running the initializer.
+			__ensure(expected == onceLocked);
+			if(int e = mlibc::sys_futex_wait((int *)&once->__mlibc_done, onceLocked, nullptr); e)
+				__ensure(!"sys_futex_wait() failed");
+			expected =  __atomic_load_n(&once->__mlibc_done, __ATOMIC_ACQUIRE);
+		}
+	}
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+// pthread_mutexattr and pthread_mutex functions.
+// ----------------------------------------------------------------------------
+
+// pthread_mutexattr functions
+int pthread_mutexattr_init(pthread_mutexattr_t *attr) {
+	SCOPE_TRACE();
+	return mlibc::thread_mutexattr_init(attr);
+}
+
+int pthread_mutexattr_destroy(pthread_mutexattr_t *attr) {
+	SCOPE_TRACE();
+	return mlibc::thread_mutexattr_destroy(attr);
+}
+
+int pthread_mutexattr_gettype(const pthread_mutexattr_t *__restrict attr, int *__restrict type) {
+	return mlibc::thread_mutexattr_gettype(attr, type);
+}
+
+int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type) {
+	return mlibc::thread_mutexattr_settype(attr, type);
+}
+
+int pthread_mutexattr_getrobust(const pthread_mutexattr_t *__restrict attr,
+		int *__restrict robust) {
+	*robust = attr->__mlibc_robust;
+	return 0;
+}
+int pthread_mutexattr_setrobust(pthread_mutexattr_t *attr, int robust) {
+	if (robust != PTHREAD_MUTEX_STALLED && robust != PTHREAD_MUTEX_ROBUST)
+		return EINVAL;
+
+	attr->__mlibc_robust = robust;
+	return 0;
+}
+
+int pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr, int *pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *__restrict attr,
+		int *__restrict protocol) {
+	*protocol = attr->__mlibc_protocol;
+	return 0;
+}
+
+int pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol) {
+	if (protocol != PTHREAD_PRIO_NONE && protocol != PTHREAD_PRIO_INHERIT
+			&& protocol != PTHREAD_PRIO_PROTECT)
+		return EINVAL;
+
+	attr->__mlibc_protocol = protocol;
+	return 0;
+}
+
+int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *__restrict attr,
+		int *__restrict prioceiling) {
+	(void)attr;
+	(void)prioceiling;
+	return EINVAL;
+}
+
+int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int prioceiling) {
+	(void)attr;
+	(void)prioceiling;
+	return EINVAL;
+}
+
+// pthread_mutex functions
+int pthread_mutex_init(pthread_mutex_t *__restrict mutex,
+		const pthread_mutexattr_t *__restrict attr) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_mutex_init(mutex, attr);
+}
+
+int pthread_mutex_destroy(pthread_mutex_t *mutex) {
+	return mlibc::thread_mutex_destroy(mutex);
+}
+
+int pthread_mutex_lock(pthread_mutex_t *mutex) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_mutex_lock(mutex);
+}
+
+int pthread_mutex_trylock(pthread_mutex_t *mutex) {
+	SCOPE_TRACE();
+
+	unsigned int this_tid = mlibc::this_tid();
+	unsigned int expected = __atomic_load_n(&mutex->__mlibc_state, __ATOMIC_RELAXED);
+	if(!expected) {
+		// Try to take the mutex here.
+		if(__atomic_compare_exchange_n(&mutex->__mlibc_state,
+						&expected, this_tid, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) {
+			__ensure(!mutex->__mlibc_recursion);
+			mutex->__mlibc_recursion = 1;
+			return 0;
+		}
+	} else {
+		// If this (recursive) mutex is already owned by us, increment the recursion level.
+		if((expected & mutex_owner_mask) == this_tid) {
+			if(!(mutex->__mlibc_flags & mutexRecursive)) {
+				return EBUSY;
+			}
+			++mutex->__mlibc_recursion;
+			return 0;
+		}
+	}
+
+	return EBUSY;
+}
+
+int pthread_mutex_timedlock(pthread_mutex_t *__restrict,
+		const struct timespec *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int pthread_mutex_unlock(pthread_mutex_t *mutex) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_mutex_unlock(mutex);
+}
+
+int pthread_mutex_consistent(pthread_mutex_t *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// ----------------------------------------------------------------------------
+// pthread_condattr and pthread_cond functions.
+// ----------------------------------------------------------------------------
+
+int pthread_condattr_init(pthread_condattr_t *attr) {
+	attr->__mlibc_pshared = PTHREAD_PROCESS_PRIVATE;
+	attr->__mlibc_clock = CLOCK_REALTIME;
+	return 0;
+}
+
+int pthread_condattr_destroy(pthread_condattr_t *attr) {
+	memset(attr, 0, sizeof(*attr));
+	return 0;
+}
+
+int pthread_condattr_getclock(const pthread_condattr_t *__restrict attr,
+		clockid_t *__restrict clock) {
+	*clock = attr->__mlibc_clock;
+	return 0;
+}
+
+int pthread_condattr_setclock(pthread_condattr_t *attr, clockid_t clock) {
+	if (clock != CLOCK_REALTIME && clock != CLOCK_MONOTONIC
+			&& clock != CLOCK_MONOTONIC_RAW && clock != CLOCK_REALTIME_COARSE
+			&& clock != CLOCK_MONOTONIC_COARSE && clock != CLOCK_BOOTTIME)
+		return EINVAL;
+
+	attr->__mlibc_clock = clock;
+	return 0;
+}
+
+int pthread_condattr_getpshared(const pthread_condattr_t *__restrict attr,
+		int *__restrict pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+
+int pthread_condattr_setpshared(pthread_condattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_cond_init(pthread_cond_t *__restrict cond, const pthread_condattr_t *__restrict attr) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_cond_init(cond, attr);
+}
+
+int pthread_cond_destroy(pthread_cond_t *cond) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_cond_destroy(cond);
+}
+
+int pthread_cond_wait(pthread_cond_t *__restrict cond, pthread_mutex_t *__restrict mutex) {
+	return pthread_cond_timedwait(cond, mutex, nullptr);
+}
+
+int pthread_cond_timedwait(pthread_cond_t *__restrict cond, pthread_mutex_t *__restrict mutex,
+		const struct timespec *__restrict abstime) {
+	return mlibc::thread_cond_timedwait(cond, mutex, abstime);
+}
+
+int pthread_cond_signal(pthread_cond_t *cond) {
+	SCOPE_TRACE();
+
+	return pthread_cond_broadcast(cond);
+}
+
+int pthread_cond_broadcast(pthread_cond_t *cond) {
+	SCOPE_TRACE();
+
+	return mlibc::thread_cond_broadcast(cond);
+}
+
+// ----------------------------------------------------------------------------
+// pthread_barrierattr and pthread_barrier functions.
+// ----------------------------------------------------------------------------
+
+int pthread_barrierattr_init(pthread_barrierattr_t *attr) {
+	attr->__mlibc_pshared = PTHREAD_PROCESS_PRIVATE;
+	return 0;
+}
+
+int pthread_barrierattr_getpshared(const pthread_barrierattr_t *__restrict attr,
+		int *__restrict pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+
+int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_barrierattr_destroy(pthread_barrierattr_t *) {
+	return 0;
+}
+
+int pthread_barrier_init(pthread_barrier_t *__restrict barrier,
+		const pthread_barrierattr_t *__restrict attr, unsigned count) {
+	if (count == 0)
+		return EINVAL;
+
+	barrier->__mlibc_waiting = 0;
+	barrier->__mlibc_inside = 0;
+	barrier->__mlibc_seq = 0;
+	barrier->__mlibc_count = count;
+
+	// Since we don't implement these yet, set a flag to error later.
+	auto pshared = attr ? attr->__mlibc_pshared : PTHREAD_PROCESS_PRIVATE;
+	barrier->__mlibc_flags = pshared;
+
+	return 0;
+}
+
+int pthread_barrier_destroy(pthread_barrier_t *barrier) {
+	// Wait until there are no threads still using the barrier.
+	unsigned inside = 0;
+	do {
+		unsigned expected = __atomic_load_n(&barrier->__mlibc_inside, __ATOMIC_RELAXED);
+		if (expected == 0)
+			break;
+
+		int e = mlibc::sys_futex_wait((int *)&barrier->__mlibc_inside, expected, nullptr);
+		if (e != 0 && e != EAGAIN && e != EINTR)
+			mlibc::panicLogger() << "mlibc: sys_futex_wait() returned error " << e << frg::endlog;
+	} while (inside > 0);
+
+	memset(barrier, 0, sizeof *barrier);
+	return 0;
+}
+
+int pthread_barrier_wait(pthread_barrier_t *barrier) {
+	if (barrier->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_barrier_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// inside is incremented on entry and decremented on exit.
+	// This is used to synchronise with pthread_barrier_destroy, to ensure that a thread doesn't pass
+	// the barrier and immediately destroy its state while other threads still rely on it.
+
+	__atomic_fetch_add(&barrier->__mlibc_inside, 1, __ATOMIC_ACQUIRE);
+
+	auto leave = [&](){
+		unsigned inside = __atomic_sub_fetch(&barrier->__mlibc_inside, 1, __ATOMIC_RELEASE);
+		if (inside == 0)
+			mlibc::sys_futex_wake((int *)&barrier->__mlibc_inside);
+	};
+
+	unsigned seq = __atomic_load_n(&barrier->__mlibc_seq, __ATOMIC_ACQUIRE);
+
+	while (true) {
+		unsigned expected = __atomic_load_n(&barrier->__mlibc_waiting, __ATOMIC_RELAXED);
+		bool swapped = __atomic_compare_exchange_n(&barrier->__mlibc_waiting, &expected, expected + 1, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
+
+		if (swapped) {
+			if (expected + 1 == barrier->__mlibc_count) {
+				// We were the last thread to hit the barrier. Reset waiters and wake the others.
+				__atomic_fetch_add(&barrier->__mlibc_seq, 1, __ATOMIC_ACQUIRE);
+				__atomic_store_n(&barrier->__mlibc_waiting, 0, __ATOMIC_RELEASE);
+
+				mlibc::sys_futex_wake((int *)&barrier->__mlibc_seq);
+
+				leave();
+				return PTHREAD_BARRIER_SERIAL_THREAD;
+			}
+
+			while (true) {
+				int e = mlibc::sys_futex_wait((int *)&barrier->__mlibc_seq, seq, nullptr);
+				if (e != 0 && e != EAGAIN && e != EINTR)
+					mlibc::panicLogger() << "mlibc: sys_futex_wait() returned error " << e << frg::endlog;
+
+				unsigned newSeq = __atomic_load_n(&barrier->__mlibc_seq, __ATOMIC_ACQUIRE);
+				if (newSeq > seq) {
+					leave();
+					return 0;
+				}
+			}
+		}
+	}
+}
+
+// ----------------------------------------------------------------------------
+// pthread_rwlock functions.
+// ----------------------------------------------------------------------------
+
+namespace {
+	void rwlock_m_lock(pthread_rwlock_t *rw, bool excl) {
+		unsigned int m_expected = __atomic_load_n(&rw->__mlibc_m, __ATOMIC_RELAXED);
+		while(true) {
+			if(m_expected) {
+				__ensure(m_expected & mutex_owner_mask);
+
+				// Try to set the waiters bit.
+				if(!(m_expected & mutex_waiters_bit)) {
+					unsigned int desired = m_expected | mutex_waiters_bit;
+					if(!__atomic_compare_exchange_n(&rw->__mlibc_m,
+							&m_expected, desired, false, __ATOMIC_RELAXED, __ATOMIC_RELAXED))
+						continue;
+				}
+
+				// Wait on the futex.
+				mlibc::sys_futex_wait((int *)&rw->__mlibc_m, m_expected | mutex_waiters_bit, nullptr);
+
+				// Opportunistically try to take the lock after we wake up.
+				m_expected = 0;
+			}else{
+				// Try to lock the mutex.
+				unsigned int desired = 1;
+				if(excl)
+					desired |= mutex_excl_bit;
+				if(__atomic_compare_exchange_n(&rw->__mlibc_m,
+						&m_expected, desired, false, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+					break;
+			}
+		}
+	}
+
+	int rwlock_m_trylock(pthread_rwlock_t *rw, bool excl) {
+		unsigned int m_expected = __atomic_load_n(&rw->__mlibc_m, __ATOMIC_RELAXED);
+		if(!m_expected) {
+			// Try to lock the mutex.
+			unsigned int desired = 1;
+			if(excl)
+				desired |= mutex_excl_bit;
+			if(__atomic_compare_exchange_n(&rw->__mlibc_m,
+					&m_expected, desired, false, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+				return 0;
+		}
+
+		__ensure(m_expected & mutex_owner_mask);
+
+		// POSIX says that this function should never block but also that
+		// readers should not be blocked by readers. We implement this by returning EAGAIN
+		// (and not EBUSY) if a reader would block a reader.
+		if(!excl && !(m_expected & mutex_excl_bit))
+			return EAGAIN;
+
+		return EBUSY;
+	}
+
+	void rwlock_m_unlock(pthread_rwlock_t *rw) {
+		auto m = __atomic_exchange_n(&rw->__mlibc_m, 0, __ATOMIC_RELEASE);
+		if(m & mutex_waiters_bit)
+			mlibc::sys_futex_wake((int *)&rw->__mlibc_m);
+	}
+}
+
+int pthread_rwlockattr_init(pthread_rwlockattr_t *attr) {
+	attr->__mlibc_pshared = PTHREAD_PROCESS_PRIVATE;
+	return 0;
+}
+
+int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *__restrict attr,
+		int *__restrict pshared) {
+	*pshared = attr->__mlibc_pshared;
+	return 0;
+}
+
+int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared) {
+	if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE)
+		return EINVAL;
+
+	attr->__mlibc_pshared = pshared;
+	return 0;
+}
+
+int pthread_rwlockattr_destroy(pthread_rwlockattr_t *) {
+	return 0;
+}
+
+int pthread_rwlock_init(pthread_rwlock_t *__restrict rw, const pthread_rwlockattr_t *__restrict attr) {
+	SCOPE_TRACE();
+	rw->__mlibc_m = 0;
+	rw->__mlibc_rc = 0;
+
+	// Since we don't implement this yet, set a flag to error later.
+	auto pshared = attr ? attr->__mlibc_pshared : PTHREAD_PROCESS_PRIVATE;
+	rw->__mlibc_flags = pshared;
+	return 0;
+}
+
+int pthread_rwlock_destroy(pthread_rwlock_t *rw) {
+	__ensure(!rw->__mlibc_m);
+	__ensure(!rw->__mlibc_rc);
+	return 0;
+}
+
+int pthread_rwlock_trywrlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Take the __mlibc_m mutex.
+	// Will be released in pthread_rwlock_unlock().
+	if(int e = rwlock_m_trylock(rw, true))
+		return e;
+
+	// Check that there are no readers.
+	unsigned int rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_ACQUIRE);
+	if(rc_expected) {
+		rwlock_m_unlock(rw);
+		return EBUSY;
+	}
+
+	return 0;
+}
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Take the __mlibc_m mutex.
+	// Will be released in pthread_rwlock_unlock().
+	rwlock_m_lock(rw, true);
+
+	// Now wait until there are no more readers.
+	unsigned int rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_ACQUIRE);
+	while(true) {
+		if(!rc_expected)
+			break;
+
+		__ensure(rc_expected & rc_count_mask);
+
+		// Try to set the waiters bit.
+		if(!(rc_expected & rc_waiters_bit)) {
+			unsigned int desired = rc_expected | rc_count_mask;
+			if(!__atomic_compare_exchange_n(&rw->__mlibc_rc,
+					&rc_expected, desired, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE))
+				continue;
+		}
+
+		// Wait on the futex.
+		mlibc::sys_futex_wait((int *)&rw->__mlibc_rc, rc_expected | rc_waiters_bit, nullptr);
+
+		// Re-check the reader counter.
+		rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_ACQUIRE);
+	}
+
+	return 0;
+}
+
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Increment the reader count while holding the __mlibc_m mutex.
+	if(int e = rwlock_m_trylock(rw, false); e)
+		return e;
+	__atomic_fetch_add(&rw->__mlibc_rc, 1, __ATOMIC_ACQUIRE);
+	rwlock_m_unlock(rw);
+
+	return 0;
+}
+
+int pthread_rwlock_rdlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	if (rw->__mlibc_flags != 0) {
+		mlibc::panicLogger() << "mlibc: pthread_rwlock_t flags were non-zero"
+			<< frg::endlog;
+	}
+
+	// Increment the reader count while holding the __mlibc_m mutex.
+	rwlock_m_lock(rw, false);
+	__atomic_fetch_add(&rw->__mlibc_rc, 1, __ATOMIC_ACQUIRE);
+	rwlock_m_unlock(rw);
+
+	return 0;
+}
+
+int pthread_rwlock_unlock(pthread_rwlock_t *rw) {
+	SCOPE_TRACE();
+
+	unsigned int rc_expected = __atomic_load_n(&rw->__mlibc_rc, __ATOMIC_RELAXED);
+	if(!rc_expected) {
+		// We are doing a write-unlock.
+		rwlock_m_unlock(rw);
+		return 0;
+	}else{
+		// We are doing a read-unlock.
+		while(true) {
+			unsigned int count = rc_expected & rc_count_mask;
+			__ensure(count);
+
+			// Try to decrement the count.
+			if(count == 1 && (rc_expected & rc_waiters_bit)) {
+				unsigned int desired = 0;
+				if(!__atomic_compare_exchange_n(&rw->__mlibc_rc,
+						&rc_expected, desired, false, __ATOMIC_RELEASE, __ATOMIC_RELAXED))
+					continue;
+
+				// Wake the futex.
+				mlibc::sys_futex_wake((int *)&rw->__mlibc_rc);
+				break;
+			}else{
+				unsigned int desired = (rc_expected & ~rc_count_mask) | (count - 1);
+				if(!__atomic_compare_exchange_n(&rw->__mlibc_rc,
+						&rc_expected, desired, false, __ATOMIC_RELEASE, __ATOMIC_RELAXED))
+					continue;
+				break;
+			}
+		}
+
+		return 0;
+	}
+}
+
+int pthread_getcpuclockid(pthread_t, clockid_t *) {
+	mlibc::infoLogger() << "mlibc: pthread_getcpuclockid() always returns ENOENT"
+			<< frg::endlog;
+	return ENOENT;
+}
diff --git a/lib/mlibc/options/posix/generic/pwd-stubs.cpp b/lib/mlibc/options/posix/generic/pwd-stubs.cpp
new file mode 100644
index 0000000..5d8f618
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/pwd-stubs.cpp
@@ -0,0 +1,284 @@
+
+#include <errno.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+
+namespace {
+	FILE *global_file; // Used by setpwent/getpwent/endpwent.
+
+	bool open_global_file() {
+		if(!global_file) {
+			global_file = fopen("/etc/passwd", "r");
+			if(!global_file) {
+				errno = EIO;
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	void close_global_file() {
+		if(global_file) {
+			fclose(global_file);
+			global_file = nullptr;
+		}
+	}
+
+	bool extract_entry(frg::string_view line, passwd *entry) {
+		frg::string_view segments[8];
+
+		// Parse the line into 7 or 8 segments.
+		size_t s = 0;
+		int n;
+		for(n = 0; n < 7; n++) {
+			size_t d = line.find_first(':', s);
+			if(d == size_t(-1))
+				break;
+			segments[n] = line.sub_string(s, d - s);
+			s = d + 1;
+		}
+		if(line.find_first(':', s) != size_t(-1))
+			return false;
+		segments[n] = line.sub_string(s, line.size() - s);
+		n++;
+
+		if(n < 7)
+			return false;
+
+		// TODO: Handle strndup() failure.
+		auto name = strndup(segments[0].data(), segments[0].size());
+		__ensure(name);
+
+		auto passwd = strndup(segments[1].data(), segments[1].size());
+		__ensure(passwd);
+
+		auto uid = segments[2].to_number<int>();
+		if(!uid)
+			return false;
+		auto gid = segments[3].to_number<int>();
+		if(!gid)
+			return false;
+
+		auto real_name = strndup(segments[4].data(), segments[4].size());
+		__ensure(real_name);
+		auto dir = strndup(segments[5].data(), segments[5].size());
+		__ensure(dir);
+		auto shell = strndup(segments[6].data(), segments[6].size());
+		__ensure(shell);
+
+		// Chop the newline off the end of shell
+		__ensure(strlen(shell) > 0);
+		shell[strlen(shell) - 1] = '\0';
+
+		entry->pw_name = name;
+		entry->pw_passwd = passwd;
+		entry->pw_uid = *uid;
+		entry->pw_gid = *gid;
+		entry->pw_dir = dir;
+		entry->pw_shell = shell;
+		entry->pw_gecos = real_name;
+		return true;
+	}
+
+	void copy_to_buffer(passwd *pwd, char *buffer, size_t size) {
+		char *pw_dir = stpcpy(buffer, pwd->pw_name) + 1;
+		free(pwd->pw_name);
+		pwd->pw_name = buffer;
+
+		char *pw_shell = stpcpy(pw_dir, pwd->pw_dir) + 1;
+		free(pwd->pw_dir);
+		pwd->pw_dir = pw_dir;
+
+		char *pw_passwd = stpcpy(pw_shell, pwd->pw_shell) + 1;
+		free(pwd->pw_shell);
+		pwd->pw_shell = pw_shell;
+
+		char *end = stpcpy(pw_passwd, pwd->pw_passwd);
+		__ensure(end <= buffer + size);
+		free(pwd->pw_passwd);
+		pwd->pw_passwd = pw_passwd;
+	}
+
+	void clear_entry(passwd *entry) {
+		free(entry->pw_name);
+		free(entry->pw_dir);
+		free(entry->pw_passwd);
+		free(entry->pw_shell);
+		entry->pw_name = nullptr;
+		entry->pw_dir = nullptr;
+		entry->pw_passwd = nullptr;
+		entry->pw_shell = nullptr;
+	}
+}
+
+struct passwd *getpwent(void) {
+	static passwd entry;
+	char line[NSS_BUFLEN_PASSWD];
+
+	if(!open_global_file()) {
+		return nullptr;
+	}
+
+	if (fgets(line, NSS_BUFLEN_PASSWD, global_file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry)) {
+			errno = EINVAL;	// I suppose this can be a valid errno?
+			return nullptr;
+		}
+		return &entry;
+	}
+
+	if(ferror(global_file)) {
+		errno = EIO;
+	}
+
+	return nullptr;
+}
+
+struct passwd *getpwnam(const char *name) {
+	static passwd entry;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file)
+		return nullptr;
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry))
+			continue;
+		if(!strcmp(entry.pw_name, name)) {
+			fclose(file);
+			return &entry;
+		}
+	}
+
+	int err = errno;
+	if(ferror(file)) {
+		err = EIO;
+	}
+
+	fclose(file);
+	errno = err;
+	return nullptr;
+}
+
+int getpwnam_r(const char *name, struct passwd *pwd, char *buffer, size_t size, struct passwd **result) {
+	*result = nullptr;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file) {
+		return EIO;
+	}
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		if(!extract_entry(line, pwd))
+			continue;
+		if(!strcmp(pwd->pw_name, name)) {
+			fclose(file);
+
+			size_t required_size = strlen(pwd->pw_name) + strlen(pwd->pw_dir)
+				+ strlen(pwd->pw_shell) + strlen(pwd->pw_passwd) + 4;
+			if (size < required_size)
+				return ERANGE;
+
+			copy_to_buffer(pwd, buffer, size);
+			*result = pwd;
+			return 0;
+		}
+	}
+
+	int ret = 0;
+	if(ferror(file)) {
+		ret = EIO;
+	}
+
+	fclose(file);
+	return ret;
+}
+
+struct passwd *getpwuid(uid_t uid) {
+	static passwd entry;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file)
+		return nullptr;
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		clear_entry(&entry);
+		if(!extract_entry(line, &entry))
+			continue;
+		if(entry.pw_uid == uid) {
+			fclose(file);
+			return &entry;
+		}
+	}
+
+	int err = ESRCH;
+	if(ferror(file)) {
+		err = EIO;
+	}
+
+	fclose(file);
+	errno = err;
+	return nullptr;
+}
+
+int getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer, size_t size, struct passwd **result) {
+	*result = nullptr;
+	auto file = fopen("/etc/passwd", "r");
+	if(!file) {
+		return EIO;
+	}
+
+	char line[NSS_BUFLEN_PASSWD];
+	while(fgets(line, NSS_BUFLEN_PASSWD, file)) {
+		if(!extract_entry(line, pwd))
+			continue;
+		if(pwd->pw_uid == uid) {
+			fclose(file);
+
+			size_t required_size = strlen(pwd->pw_name) + strlen(pwd->pw_dir)
+				+ strlen(pwd->pw_shell) + + strlen(pwd->pw_passwd) + 4;
+			if (size < required_size)
+				return ERANGE;
+
+			copy_to_buffer(pwd, buffer, size);
+			*result = pwd;
+			return 0;
+		}
+	}
+
+	int ret = 0;
+	if(ferror(file)) {
+		ret = EIO;
+	}
+
+	fclose(file);
+	return ret;
+}
+
+void setpwent(void) {
+	if(!open_global_file()) {
+		return;
+	}
+	rewind(global_file);
+}
+
+void endpwent(void) {
+	close_global_file();
+}
+
+int putpwent(const struct passwd *, FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+struct passwd *fgetpwent(FILE *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/resolv_conf.cpp b/lib/mlibc/options/posix/generic/resolv_conf.cpp
new file mode 100644
index 0000000..a5c3aa7
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/resolv_conf.cpp
@@ -0,0 +1,42 @@
+#include <mlibc/resolv_conf.hpp>
+#include <mlibc/allocator.hpp>
+#include <stdio.h>
+#include <ctype.h>
+
+namespace mlibc {
+
+frg::optional<struct nameserver_data> get_nameserver() {
+	auto file = fopen("/etc/resolv.conf", "r");
+	if (!file)
+		return frg::null_opt;
+
+	char line[128];
+	struct nameserver_data ret;
+	while (fgets(line, 128, file)) {
+		char *pos;
+		if (!strchr(line, '\n') && !feof(file)) {
+			// skip truncated lines
+			for (int c = getc(file); c != '\n' && c != EOF; c = getc(file));
+			continue;
+		}
+
+		// TODO(geert): resolv.conf can actually have multiple nameservers
+		// but we just pick the first one for now
+		if (!strncmp(line, "nameserver", 10) && isspace(line[10])) {
+			char *end;
+			for (pos = line + 11; isspace(*pos); pos++);
+			for (end = pos; *end && !isspace(*end); end++);
+			*end = '\0';
+			ret.name = frg::string<MemoryAllocator>(
+					pos, end - pos, getAllocator());
+			break;
+		}
+	}
+
+	fclose(file);
+	if(ret.name.empty())
+		return frg::null_opt;
+	return ret;
+}
+
+} // namespace mlibc
diff --git a/lib/mlibc/options/posix/generic/sched-stubs.cpp b/lib/mlibc/options/posix/generic/sched-stubs.cpp
new file mode 100644
index 0000000..9d75d50
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sched-stubs.cpp
@@ -0,0 +1,50 @@
+
+#include <bits/ensure.h>
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int sched_yield(void) {
+	if(mlibc::sys_yield) {
+		mlibc::sys_yield();
+	}else{
+		// Missing sched_yield() is not an error.
+		MLIBC_MISSING_SYSDEP();
+	}
+	return 0;
+}
+
+int sched_get_priority_max(int policy) {
+	int res = 0;
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_get_max_priority, -1);
+	if(int e = sysdep(policy, &res); e) {
+		errno = e;
+		return -1;
+	}
+	return res;
+}
+
+int sched_get_priority_min(int policy) {
+	int res = 0;
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_get_min_priority, -1);
+	if(int e = sysdep(policy, &res); e) {
+		errno = e;
+		return -1;
+	}
+	return res;
+}
+
+int sched_setscheduler(pid_t, int, const struct sched_param *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sched_getparam(pid_t, struct sched_param *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/search.cpp b/lib/mlibc/options/posix/generic/search.cpp
new file mode 100644
index 0000000..e6f8c1d
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/search.cpp
@@ -0,0 +1,151 @@
+
+#include <bits/ensure.h>
+#include <search.h>
+#include <stddef.h>
+#include <new>
+#include <mlibc/allocator.hpp>
+#include <frg/stack.hpp>
+#include <stdlib.h>
+
+struct node {
+	const void *key;
+	void *a[2];
+	int h;
+};
+
+namespace {
+	int height(struct node *node) {
+		return node ? node->h : 0;
+	}
+
+	int rotate(struct node **nodep, int side) {
+		struct node *node = *nodep;
+		struct node *x = static_cast<struct node *>(node->a[side]);
+		struct node *y = static_cast<struct node *>(x->a[!side]);
+		struct node *z = static_cast<struct node *>(x->a[side]);
+
+		int height_node = node->h;
+		int height_y = height(y);
+		if (height_y > height(z)) {
+			// Perform double rotation
+			node->a[side] = y->a[!side];
+			x->a[!side] = y->a[side];
+			y->a[!side] = node;
+			y->a[side] = x;
+			node->h = height_y;
+			x->h = height_y;
+			y->h = height_y + 1;
+		} else {
+			// Perform single rotation
+			node->a[side] = y;
+			x->a[!side] = node;
+			node->h = height_y + 1;
+			x->h = height_y + 2;
+			y = x;
+
+		}
+		*nodep = y;
+		return y->h - height_node;
+	}
+
+	int balance_tree(struct node **nodep) {
+		struct node *node = *nodep;
+		int height_a = height(static_cast<struct node *>(node->a[0]));
+		int height_b = height(static_cast<struct node *>(node->a[1]));
+		if (height_a - height_b < 2) {
+			int old = node->h;
+			node->h = height_a < height_b ? height_b + 1 : height_a + 1;
+			return node->h - old;
+		}
+
+		return rotate(nodep, height_a < height_b);
+	}
+}
+
+void *tsearch(const void *key, void **rootp, int(*compar)(const void *, const void *)) {
+	if (!rootp)
+		return NULL;
+
+	struct node *n = static_cast<struct node *>(*rootp);
+	frg::stack<struct node **, MemoryAllocator> nodes(getAllocator());
+	nodes.push(reinterpret_cast<struct node **>(rootp));
+	int c = 0;
+	for (;;) {
+		if (!n)
+			break;
+		c = compar(key, n->key);
+		if (!c)
+			return n;
+		nodes.push(reinterpret_cast<struct node **>(&n->a[c > 0]));
+		n = static_cast<struct node *>(n->a[c > 0]);
+	}
+
+	struct node *insert = static_cast<struct node*>(malloc(sizeof(struct node)));
+	if (!insert)
+		return NULL;
+	insert->key = key;
+	insert->a[0] = insert->a[1] = NULL;
+	insert->h = 1;
+
+	(*nodes.top()) = insert;
+	nodes.pop();
+	while(nodes.size() && balance_tree(nodes.top())) nodes.pop();
+	return insert;
+}
+
+// This implementation is taken from musl
+void *tfind(const void *key, void *const *rootp, int (*compar)(const void *, const void *)) {
+	if(!rootp)
+		return 0;
+
+	struct node *n = (struct node *)*rootp;
+	for(;;) {
+		if(!n)
+			break;
+		int c = compar(key, n->key);
+		if(!c)
+			break;
+		n = (struct node *)n->a[c > 0];
+	}
+	return n;
+}
+
+void *tdelete(const void *, void **, int(*compar)(const void *, const void *)) {
+	(void)compar;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void twalk(const void *, void (*action)(const void *, VISIT, int)) {
+	(void)action;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void tdestroy(void *, void (*free_node)(void *)) {
+	(void)free_node;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void *lsearch(const void *key, void *base, size_t *nelp, size_t width,
+		int (*compar)(const void *, const void *)) {
+	(void)key;
+	(void)base;
+	(void)nelp;
+	(void)width;
+	(void)compar;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void *lfind(const void *key, const void *base, size_t *nelp,
+		size_t width, int (*compar)(const void *, const void *)) {
+	(void)key;
+	(void)base;
+	(void)nelp;
+	(void)width;
+	(void)compar;
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/semaphore-stubs.cpp b/lib/mlibc/options/posix/generic/semaphore-stubs.cpp
new file mode 100644
index 0000000..d41eccb
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/semaphore-stubs.cpp
@@ -0,0 +1,114 @@
+#include <semaphore.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/ansi-sysdeps.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+static constexpr unsigned int semaphoreHasWaiters = static_cast<uint32_t>(1 << 31);
+static constexpr unsigned int semaphoreCountMask = static_cast<uint32_t>(1 << 31) - 1;
+
+int sem_init(sem_t *sem, int pshared, unsigned int initial_count) {
+	if (pshared) {
+		mlibc::infoLogger() << "mlibc: shared semaphores are unsuppored" << frg::endlog;
+		errno = ENOSYS;
+		return -1;
+	}
+
+	if (initial_count > SEM_VALUE_MAX) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	sem->__mlibc_count = initial_count;
+
+	return 0;
+}
+
+int sem_destroy(sem_t *) {
+	return 0;
+}
+
+int sem_wait(sem_t *sem) {
+	unsigned int state = 0;
+
+	while (1) {
+		if (!(state & semaphoreCountMask)) {
+			if (__atomic_compare_exchange_n(&sem->__mlibc_count, &state, semaphoreHasWaiters,
+						false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE)) {
+				int e = mlibc::sys_futex_wait((int *)&sem->__mlibc_count, state, nullptr);
+				if (e == 0 || e == EAGAIN) {
+					continue;
+				} else if (e == EINTR) {
+					errno = EINTR;
+					return -1;
+				} else {
+					mlibc::panicLogger() << "sys_futex_wait() failed with error code " << e << frg::endlog;
+				}
+			}
+		} else {
+			unsigned int desired = (state - 1);
+			if (__atomic_compare_exchange_n(&sem->__mlibc_count, &state, desired, false,
+						__ATOMIC_RELAXED, __ATOMIC_RELAXED))
+				return 0;
+		}
+	}
+}
+
+int sem_timedwait(sem_t *sem, const struct timespec *) {
+	mlibc::infoLogger() << "\e[31mmlibc: sem_timedwait is implemented as sem_wait\e[0m" << frg::endlog;
+	return sem_wait(sem);
+}
+
+int sem_post(sem_t *sem) {
+	auto old_count = __atomic_load_n(&sem->__mlibc_count, __ATOMIC_RELAXED) & semaphoreCountMask;
+
+	if (old_count + 1 > SEM_VALUE_MAX) {
+		errno = EOVERFLOW;
+		return -1;
+	}
+
+	auto state = __atomic_exchange_n(&sem->__mlibc_count, old_count + 1, __ATOMIC_RELEASE);
+
+	if (state & semaphoreHasWaiters)
+		if (int e = mlibc::sys_futex_wake((int *)&sem->__mlibc_count); e)
+			__ensure(!"sys_futex_wake() failed");
+
+	return 0;
+}
+
+sem_t *sem_open(const char *, int, ...) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_close(sem_t *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_getvalue(sem_t *, int *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_unlink(const char *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int sem_trywait(sem_t *sem) {
+	while (true) {
+		auto state = __atomic_load_n(&sem->__mlibc_count, __ATOMIC_ACQUIRE);
+
+		if (state & semaphoreHasWaiters) {
+			return EAGAIN;
+		}
+
+		auto desired = state - 1;
+		if (__atomic_compare_exchange_n(&sem->__mlibc_count, &state, desired, false, __ATOMIC_RELEASE, __ATOMIC_RELAXED)) {
+			return 0;
+		}
+	}
+}
diff --git a/lib/mlibc/options/posix/generic/services.cpp b/lib/mlibc/options/posix/generic/services.cpp
new file mode 100644
index 0000000..8ae0656
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/services.cpp
@@ -0,0 +1,222 @@
+#include <mlibc/services.hpp>
+#include <netdb.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <mlibc/debug.hpp>
+
+namespace mlibc {
+
+static int parse_rest(service_buf &buf, char *end, int proto) {
+	if (!strncmp(end, "/udp", 4)) {
+		if (proto == IPPROTO_TCP && proto != -1)
+			return 0;
+		buf.protocol = IPPROTO_UDP;
+		buf.socktype = SOCK_DGRAM;
+	} else if (!strncmp(end, "/tcp", 4)) {
+		if (proto == IPPROTO_UDP && proto != -1)
+			return 0;
+		buf.protocol = IPPROTO_TCP;
+		buf.socktype = SOCK_STREAM;
+	} else {
+		return 0;
+	}
+
+	//TODO(geert): also parse aliases.
+
+	return 1;
+}
+
+static int lookup_serv_file_port(service_result &buf, int proto, int port) {
+	auto file = fopen(_PATH_SERVICES, "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line_buf[129] = {0};
+	char *line = line_buf + 1;
+	while(fgets(line, 128, file)) {
+		int name_length = 0;
+		char *pos;
+		// easy way to handle comments, just move the end of the line
+		// to the beginning of the comment
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		char *end = NULL;
+		for (pos = line; *pos; pos++) {
+			for (; isalpha(*pos); pos++);
+			int rport = strtoul(pos, &end, 10);
+			if (rport != port || rport > 65535) {
+				pos = end;
+				continue;
+			}
+
+			// We have found the port, time to rewind to the start
+			// of the line.
+			for (; pos[-1]; pos--)
+				if(!isspace(pos[-1]))
+					name_length++;
+			break;
+		}
+
+		if (!pos)
+			continue;
+
+		if (!name_length)
+			continue;
+
+		auto name = frg::string<MemoryAllocator>(pos, name_length,
+				getAllocator());
+
+		struct service_buf sbuf = {};
+		sbuf.port = port;
+		sbuf.name = std::move(name);
+		if (!parse_rest(sbuf, end, proto))
+			continue;
+		buf.push_back(std::move(sbuf));
+	}
+
+	fclose(file);
+	return buf.size();
+}
+
+static int lookup_serv_file_name(service_result &buf, const char *name,
+		int proto) {
+	auto file = fopen(_PATH_SERVICES, "r");
+	if (!file) {
+		switch (errno) {
+			case ENOENT:
+			case ENOTDIR:
+			case EACCES:
+				return -EAI_SERVICE;
+			default:
+				return -EAI_SYSTEM;
+		}
+	}
+
+	char line[128];
+	int name_length = strlen(name);
+	while(fgets(line, 128, file)) {
+		char *pos;
+		// easy way to handle comments, just move the end of the line
+		// to the beginning of the comment
+		if ((pos = strchr(line, '#'))) {
+			*pos++ = '\n';
+			*pos = '\0';
+		}
+
+		for (pos = line; (pos = strstr(pos, name)); pos++) {
+			// the name must start and end with a space
+			if (pos > line && !isspace(pos[-1]))
+				continue;
+			if (pos[name_length] && !isspace(pos[name_length]))
+				continue;
+			break;
+		}
+		if (!pos)
+			continue;
+
+		// Skip the name at the beginning of the line.
+		for(pos = line; *pos && !isspace(*pos); pos++)
+			;
+
+		char *end = NULL;
+		int port = strtoul(pos, &end, 10);
+		if (port > 65535 || end == pos)
+			continue;
+
+		struct service_buf sbuf;
+		sbuf.port = port;
+		sbuf.name = frg::string<MemoryAllocator>(name, getAllocator());
+		if (!parse_rest(sbuf, end, proto))
+			continue;
+
+		buf.push_back(sbuf);
+
+	}
+
+	fclose(file);
+	return buf.size();
+}
+
+
+// This function returns a negative error code, since a positive
+// return code means success.
+int lookup_serv_by_name(service_result &buf, const char *name, int proto,
+		int socktype, int flags) {
+	switch(socktype) {
+		case SOCK_STREAM:
+			if (!proto)
+				proto = IPPROTO_TCP;
+			else if (proto != IPPROTO_TCP)
+				return -EAI_SERVICE;
+			break;
+		case SOCK_DGRAM:
+			if (!proto)
+				proto = IPPROTO_UDP;
+			else if (proto != IPPROTO_UDP)
+				return -EAI_SERVICE;
+			break;
+		case 0:
+			break;
+		default:
+			if (name)
+				return -EAI_SERVICE;
+			buf[0].port = 0;
+			buf[0].socktype = socktype;
+			buf[0].protocol = proto;
+			return 1;
+	}
+
+	char *end = nullptr;
+	unsigned int port = 0;
+	int count = 0;
+
+	if (name) {
+		if (!*name)
+			return -EAI_SERVICE;
+		port = strtoul(name, &end, 10);
+	}
+	// The end pointer is a null pointer so the name was a port
+	// or the name was not specified.
+	if (!end || !*end) {
+		if (proto != IPPROTO_UDP) {
+			buf[count].port = port;
+			buf[count].protocol = IPPROTO_TCP;
+			buf[count].socktype = SOCK_STREAM;
+			count++;
+		}
+		if (proto != IPPROTO_TCP) {
+			buf[count].port = port;
+			buf[count].protocol = IPPROTO_UDP;
+			buf[count].socktype = SOCK_DGRAM;
+			count++;
+		}
+		return count;
+	}
+
+	if (flags & AI_NUMERICSERV)
+		return -EAI_NONAME;
+
+	return lookup_serv_file_name(buf, name, proto);
+}
+
+int lookup_serv_by_port(service_result &buf, int proto, int port) {
+	return lookup_serv_file_port(buf, proto, port);
+}
+
+} // namespace mlibc
diff --git a/lib/mlibc/options/posix/generic/spawn-stubs.cpp b/lib/mlibc/options/posix/generic/spawn-stubs.cpp
new file mode 100644
index 0000000..cf7edfc
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/spawn-stubs.cpp
@@ -0,0 +1,376 @@
+
+#include <spawn.h>
+#include <errno.h>
+#include <pthread.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+
+/*
+ * Musl places this in a seperate header called fdop.h
+ * This header isn't present in glibc, or on my host, so I
+ * include it's contents here
+ */
+
+#define FDOP_CLOSE 1
+#define FDOP_DUP2 2
+#define FDOP_OPEN 3
+#define FDOP_CHDIR 4
+#define FDOP_FCHDIR 5
+
+struct fdop {
+	struct fdop *next, *prev;
+	int cmd, fd, srcfd, oflag;
+	mode_t mode;
+	char path[];
+};
+
+/*
+ * This posix_spawn implementation is taken from musl
+ */
+
+static unsigned long handler_set[NSIG / (8 * sizeof(long))];
+
+static void __get_handler_set(sigset_t *set) {
+	memcpy(set, handler_set, sizeof handler_set);
+}
+
+struct args {
+	int p[2];
+	sigset_t oldmask;
+	const char *path;
+	const posix_spawn_file_actions_t *fa;
+	const posix_spawnattr_t *__restrict attr;
+	char *const *argv, *const *envp;
+};
+
+static int child(void *args_vp) {
+	int i, ret;
+	struct sigaction sa = {};
+	struct args *args = (struct args *)args_vp;
+	int p = args->p[1];
+	const posix_spawn_file_actions_t *fa = args->fa;
+	const posix_spawnattr_t *__restrict attr = args->attr;
+	sigset_t hset;
+	bool use_execvpe = false;
+
+	if(attr->__fn)
+		use_execvpe = true;
+
+	close(args->p[0]);
+
+	/* All signal dispositions must be either SIG_DFL or SIG_IGN
+	 * before signals are unblocked. Otherwise a signal handler
+	 * from the parent might get run in the child while sharing
+	 * memory, with unpredictable and dangerous results. To
+	 * reduce overhead, sigaction has tracked for us which signals
+	 * potentially have a signal handler. */
+	__get_handler_set(&hset);
+	for(i = 1; i < NSIG; i++) {
+		if((attr->__flags & POSIX_SPAWN_SETSIGDEF) && sigismember(&attr->__def, i)) {
+			sa.sa_handler = SIG_DFL;
+		} else if(sigismember(&hset, i)) {
+			if (i - 32 < 3) {
+				sa.sa_handler = SIG_IGN;
+			} else {;
+				sigaction(i, 0, &sa);
+				if(sa.sa_handler == SIG_IGN)
+					continue;
+				sa.sa_handler = SIG_DFL;
+			}
+		} else {
+			continue;
+		}
+		sigaction(i, &sa, 0);
+	}
+
+	if(attr->__flags & POSIX_SPAWN_SETSID) {
+		if((ret = setsid()) < 0)
+			goto fail;
+	}
+
+	if(attr->__flags & POSIX_SPAWN_SETPGROUP) {
+		mlibc::infoLogger() << "mlibc: posix_spawn: ignoring SETPGROUP" << frg::endlog;
+		//if((ret = setpgid(0, attr->__pgrp)))
+		//	goto fail;
+	}
+
+	if(attr->__flags & POSIX_SPAWN_RESETIDS) {
+		if((ret = setgid(getgid())) || (ret = setuid(getuid())) )
+			goto fail;
+	}
+
+	if(fa && fa->__actions) {
+		struct fdop *op;
+		int fd;
+		for(op = (struct fdop *)fa->__actions; op->next; op = op->next);
+		for(; op; op = op->prev) {
+			/* It's possible that a file operation would clobber
+			 * the pipe fd used for synchronizing with the
+			 * parent. To avoid that, we dup the pipe onto
+			 * an unoccupied fd. */
+			if(op->fd == p) {
+				ret = dup(p);
+				if(ret < 0)
+					goto fail;
+				close(p);
+				p = ret;
+			}
+			switch(op->cmd) {
+			case FDOP_CLOSE:
+				close(op->fd);
+				break;
+			case FDOP_DUP2:
+				fd = op->srcfd;
+				if(fd == p) {
+					ret = -EBADF;
+					goto fail;
+				}
+				if(fd != op->fd) {
+					if((ret = dup2(fd, op->fd)) < 0)
+						goto fail;
+				} else {
+					ret = fcntl(fd, F_GETFD);
+					ret = fcntl(fd, F_SETFD, ret & ~FD_CLOEXEC);
+					if(ret < 0)
+						goto fail;
+				}
+				break;
+			case FDOP_OPEN:
+				fd = open(op->path, op->oflag, op->mode);
+				if((ret = fd) < 0)
+					goto fail;
+				if(fd != op->fd) {
+					if((ret = dup2(fd, op->fd)) < 0)
+						goto fail;
+					close(fd);
+				}
+				break;
+			case FDOP_CHDIR:
+				ret = chdir(op->path);
+				if(ret < 0)
+					goto fail;
+				break;
+			case FDOP_FCHDIR:
+				ret = fchdir(op->fd);
+				if(ret < 0)
+					goto fail;
+				break;
+			}
+		}
+	}
+
+	/* Close-on-exec flag may have been lost if we moved the pipe
+	 * to a different fd. */
+	fcntl(p, F_SETFD, FD_CLOEXEC);
+
+	pthread_sigmask(SIG_SETMASK, (attr->__flags & POSIX_SPAWN_SETSIGMASK)
+		? &attr->__mask : &args->oldmask, 0);
+
+	if(use_execvpe)
+		execvpe(args->path, args->argv, args->envp);
+	else
+		execve(args->path, args->argv, args->envp);
+	ret = -errno;
+
+fail:
+	/* Since sizeof errno < PIPE_BUF, the write is atomic. */
+	ret = -ret;
+	if(ret)
+		while(write(p, &ret, sizeof ret) < 0);
+	_exit(127);
+}
+
+int posix_spawn(pid_t *__restrict res, const char *__restrict path,
+		const posix_spawn_file_actions_t *file_actions,
+		const posix_spawnattr_t *__restrict attrs,
+		char *const argv[], char *const envp[]) {
+	pid_t pid;
+	int ec = 0, cs;
+	struct args args;
+	const posix_spawnattr_t empty_attr = {};
+	sigset_t full_sigset;
+	sigfillset(&full_sigset);
+
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
+	args.path = path;
+	args.fa = file_actions;
+	args.attr = attrs ? attrs : &empty_attr;
+	args.argv = argv;
+	args.envp = envp;
+	pthread_sigmask(SIG_BLOCK, &full_sigset, &args.oldmask);
+
+	/* The lock guards both against seeing a SIGABRT disposition change
+	 * by abort and against leaking the pipe fd to fork-without-exec. */
+	//LOCK(__abort_lock);
+
+	if(pipe2(args.p, O_CLOEXEC)) {
+		//UNLOCK(__abort_lock);
+		ec = errno;
+		goto fail;
+	}
+
+	/* Mlibc change: We use fork + execve, as clone is not implemented.
+	 * This yields the same result in the end. */
+	//pid = clone(child, stack + sizeof stack, CLONE_VM | CLONE_VFORK | SIGCHLD, &args);
+	pid = fork();
+	if(!pid) {
+		child(&args);
+	}
+	close(args.p[1]);
+	//UNLOCK(__abort_lock);
+
+	if(pid > 0) {
+		if(read(args.p[0], &ec, sizeof ec) != sizeof ec)
+			ec = 0;
+		else
+			waitpid(pid, 0, 0);
+	} else {
+		ec = -pid;
+	}
+
+	close(args.p[0]);
+
+	if(!ec && res)
+		*res = pid;
+
+fail:
+	pthread_sigmask(SIG_SETMASK, &args.oldmask, 0);
+	pthread_setcancelstate(cs, 0);
+
+	return ec;
+}
+
+int posix_spawnattr_init(posix_spawnattr_t *attr) {
+	*attr = (posix_spawnattr_t){};
+	return 0;
+}
+
+int posix_spawnattr_destroy(posix_spawnattr_t *) {
+	return 0;
+}
+
+int posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags) {
+	const unsigned all_flags = 
+			POSIX_SPAWN_RESETIDS |
+			POSIX_SPAWN_SETPGROUP |
+			POSIX_SPAWN_SETSIGDEF |
+			POSIX_SPAWN_SETSIGMASK |
+			POSIX_SPAWN_SETSCHEDPARAM |
+			POSIX_SPAWN_SETSCHEDULER |
+			POSIX_SPAWN_USEVFORK |
+			POSIX_SPAWN_SETSID;
+	if(flags & ~all_flags)
+		return EINVAL;
+	attr->__flags = flags;
+	return 0;
+}
+
+int posix_spawnattr_setsigdefault(posix_spawnattr_t *__restrict attr,
+		const sigset_t *__restrict sigdefault) {
+	attr->__def = *sigdefault;
+	return 0;
+}
+
+int posix_spawnattr_setschedparam(posix_spawnattr_t *__restrict,
+		const struct sched_param *__restrict) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int posix_spawnattr_setschedpolicy(posix_spawnattr_t *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int posix_spawnattr_setsigmask(posix_spawnattr_t *__restrict attr,
+		const sigset_t *__restrict sigmask) {
+	attr->__mask = *sigmask;
+	return 0;
+}
+
+int posix_spawnattr_setpgroup(posix_spawnattr_t *attr, pid_t pgroup) {
+	attr->__pgrp = pgroup;
+	return 0;
+}
+
+int posix_spawn_file_actions_init(posix_spawn_file_actions_t *file_actions) {
+	file_actions->__actions = 0;
+	return 0;
+}
+
+int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *file_actions) {
+	struct fdop *op = (struct fdop *)file_actions->__actions, *next;
+	while(op) {
+		next = op->next;
+		free(op);
+		op = next;
+	}
+	return 0;
+}
+
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions,
+		int fildes, int newfildes) {
+	struct fdop *op = (struct fdop *)malloc(sizeof *op);
+	if(!op)
+		return ENOMEM;
+	op->cmd = FDOP_DUP2;
+	op->srcfd = fildes;
+	op->fd = newfildes;
+	if((op->next = (struct fdop *)file_actions->__actions))
+		op->next->prev = op;
+	op->prev = 0;
+	file_actions->__actions = op;
+	return 0;
+}
+
+int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
+		int fildes) {
+	struct fdop *op = (struct fdop *)malloc(sizeof *op);
+	if(!op)
+		return ENOMEM;
+	op->cmd = FDOP_CLOSE;
+	op->fd = fildes;
+	if((op->next = (struct fdop *)file_actions->__actions))
+		op->next->prev = op;
+	op->prev = 0;
+	file_actions->__actions = op;
+	return 0;
+}
+
+int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *__restrict file_actions,
+		int fildes, const char *__restrict path, int oflag, mode_t mode) {
+	struct fdop *op = (struct fdop *)malloc(sizeof *op + strlen(path) + 1);
+	if(!op)
+		return ENOMEM;
+	op->cmd = FDOP_OPEN;
+	op->fd = fildes;
+	op->oflag = oflag;
+	op->mode = mode;
+	strcpy(op->path, path);
+	if((op->next = (struct fdop *)file_actions->__actions))
+		op->next->prev = op;
+	op->prev = 0;
+	file_actions->__actions = op;
+	return 0;
+}
+
+int posix_spawnp(pid_t *__restrict pid, const char *__restrict file,
+		const posix_spawn_file_actions_t *file_actions,
+		const posix_spawnattr_t *__restrict attrp,
+		char *const argv[], char *const envp[]) {
+	posix_spawnattr_t spawnp_attr = {};
+	if(attrp)
+		spawnp_attr = *attrp;
+	spawnp_attr.__fn = (void *)execvpe;	
+	return posix_spawn(pid, file, file_actions, &spawnp_attr, argv, envp);
+}
+
diff --git a/lib/mlibc/options/posix/generic/strings-stubs.cpp b/lib/mlibc/options/posix/generic/strings-stubs.cpp
new file mode 100644
index 0000000..524c424
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/strings-stubs.cpp
@@ -0,0 +1,107 @@
+
+#include <strings.h>
+#include <string.h>
+
+#include <ctype.h>
+#include <bits/ensure.h>
+#include <mlibc/strings.hpp>
+
+char *index (const char *s, int c) {
+	return strchr(s, c);
+}
+
+char *rindex(const char *s, int c) {
+	return strrchr(s, c);
+}
+
+namespace {
+
+	template<typename T>
+	int ffs_generic(T i) {
+		//Non-portably assume a byte has 8 bits; fine in all plausible cases.
+		for(size_t b = 0; b < sizeof(T) * 8;)
+			if(i & (static_cast<T>(0x1) << b++))
+				return b;
+
+		return 0;
+	}
+
+}
+
+// On RISC-V, __builtin_ffs just calls into ffs, so we can't use it here.
+#if defined(__has_builtin) && !defined(__riscv)
+#	if __has_builtin(__builtin_ffs)
+#		define __mlibc_ffs __builtin_ffs
+#	endif
+#	if __has_builtin(__builtin_ffsl)
+#		define __mlibc_ffsl __builtin_ffsl
+#	endif
+#	if __has_builtin(__builtin_ffsll)
+#		define __mlibc_ffsll __builtin_ffsll
+#	endif
+#endif
+
+int ffs(int i) {
+#ifdef __mlibc_ffs
+	return __mlibc_ffs(i);
+#else
+	return ffs_generic<int>(i);
+#endif
+}
+
+/*
+	Both ffsl() and ffsll() are glibc extensions
+	defined in string.h. They are however implemented
+	here because of similarity in logic and
+	shared code.
+*/
+
+int ffsl(long i) {
+#ifdef __mlibc_ffsl
+	return __mlibc_ffsl(i);
+#else
+	return ffs_generic<long>(i);
+#endif
+}
+
+int ffsll(long long i) {
+#ifdef __mlibc_ffsll
+	return __mlibc_ffsll(i);
+#else
+	return ffs_generic<long long>(i);
+#endif
+}
+
+int strcasecmp(const char *a, const char *b) {
+	size_t i = 0;
+	while(true) {
+		unsigned char a_byte = tolower(a[i]);
+		unsigned char b_byte = tolower(b[i]);
+		if(!a_byte && !b_byte)
+			return 0;
+		// If only one char is null, one of the following cases applies.
+		if(a_byte < b_byte)
+			return -1;
+		if(a_byte > b_byte)
+			return 1;
+		i++;
+	}
+}
+
+int strncasecmp(const char *a, const char *b, size_t size) {
+	return mlibc::strncasecmp(a, b, size);
+}
+
+// Marked as obsolete in posix 2008 but used by at least tracker
+int bcmp(const void *s1, const void *s2, size_t n) {
+	return memcmp(s1, s2, n);
+}
+
+void bcopy(const void *s1, void *s2, size_t n) {
+	memmove(s2, s1, n);
+}
+
+void bzero(void *s, size_t n) {
+	memset(s, 0, n);
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-file-stubs.cpp b/lib/mlibc/options/posix/generic/sys-file-stubs.cpp
new file mode 100644
index 0000000..e1cc9ab
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-file-stubs.cpp
@@ -0,0 +1,16 @@
+
+#include <sys/file.h>
+#include <mlibc/posix-sysdeps.hpp>
+#include <errno.h>
+
+#include <bits/ensure.h>
+
+int flock(int fd, int opt) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_flock, -1);
+	if(int e = mlibc::sys_flock(fd, opt); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-ipc.cpp b/lib/mlibc/options/posix/generic/sys-ipc.cpp
new file mode 100644
index 0000000..b9e0d3d
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-ipc.cpp
@@ -0,0 +1,8 @@
+#include <sys/ipc.h>
+
+#include <bits/ensure.h>
+
+key_t ftok(const char *, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-mman-stubs.cpp b/lib/mlibc/options/posix/generic/sys-mman-stubs.cpp
new file mode 100644
index 0000000..9383976
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-mman-stubs.cpp
@@ -0,0 +1,177 @@
+
+#include <errno.h>
+#include <limits.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <bits/ensure.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int mprotect(void *pointer, size_t size, int prot) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_vm_protect, -1);
+	if(int e = mlibc::sys_vm_protect(pointer, size, prot); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mlock(const void *addr, size_t len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mlock, -1);
+	if(int e = mlibc::sys_mlock(addr, len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mlockall(int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mlockall, -1);
+	if(int e = mlibc::sys_mlockall(flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int munlock(const void *addr, size_t len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_munlock, -1);
+	if(int e = mlibc::sys_munlock(addr, len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int munlockall(void) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_munlockall, -1);
+	if(int e = mlibc::sys_munlockall(); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+
+int posix_madvise(void *, size_t, int) {
+	mlibc::infoLogger() << "\e[31m" "mlibc: posix_madvise() fails unconditionally" "\e[39m"
+			<< frg::endlog;
+	return ENOSYS;
+}
+
+int msync(void *addr, size_t length, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_msync, -1);
+	if(int e = mlibc::sys_msync(addr, length, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+void *mremap(void *pointer, size_t size, size_t new_size, int flags, ...) {
+	__ensure(flags == MREMAP_MAYMOVE);
+
+	void *window;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_vm_remap, (void *)-1);
+	if(int e = mlibc::sys_vm_remap(pointer, size, new_size, &window); e) {
+		errno = e;
+		return (void *)-1;
+	}
+	return window;
+}
+
+int remap_file_pages(void *, size_t, int, size_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void *mmap(void *hint, size_t size, int prot, int flags, int fd, off_t offset) {
+	void *window;
+	if(int e = mlibc::sys_vm_map(hint, size, prot, flags, fd, offset, &window); e) {
+		errno = e;
+		return (void *)-1;
+	}
+	return window;
+}
+
+int munmap(void *pointer, size_t size) {
+	if(int e = mlibc::sys_vm_unmap(pointer, size); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// The implementation of shm_open and shm_unlink is taken from musl.
+namespace {
+	char *shm_mapname(const char *name, char *buf) {
+		char *p;
+		while(*name == '/')
+			name++;
+		if(*(p = strchrnul(name, '/')) || p == name ||
+			(p - name <= 2 && name[0] == '.' && p[-1] == '.')) {
+			errno = EINVAL;
+			return 0;
+		}
+		if(p - name > NAME_MAX) {
+			errno = ENAMETOOLONG;
+			return 0;
+		}
+		memcpy(buf, "/dev/shm/", 9);
+		memcpy(buf + 9, name, p - name + 1);
+		return buf;
+	}
+}
+
+int shm_open(const char *name, int flags, mode_t mode) {
+	int cs;
+	char buf[NAME_MAX + 10];
+	if(!(name = shm_mapname(name, buf)))
+		return -1;
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	int fd = open(name, flags | O_NOFOLLOW | O_CLOEXEC | O_NONBLOCK, mode);
+	pthread_setcancelstate(cs, 0);
+	return fd;
+}
+
+int shm_unlink(const char *name) {
+	char buf[NAME_MAX + 10];
+	if(!(name = shm_mapname(name, buf)))
+		return -1;
+	return unlink(name);
+}
+
+#if __MLIBC_LINUX_OPTION
+int memfd_create(const char *name, unsigned int flags) {
+	int ret = -1;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_memfd_create, -1);
+	if(int e = mlibc::sys_memfd_create(name, flags, &ret)) {
+		errno = e;
+		return -1;
+	}
+
+	return ret;
+}
+
+int madvise(void *addr, size_t length, int advice) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_madvise, -1);
+	if(int e = mlibc::sys_madvise(addr, length, advice)) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int mincore(void *addr, size_t length, unsigned char *vec) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_munlockall, -1);
+	if(int e = mlibc::sys_mincore(addr, length, vec); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+#endif /* __MLIBC_LINUX_OPTION */
diff --git a/lib/mlibc/options/posix/generic/sys-msg.cpp b/lib/mlibc/options/posix/generic/sys-msg.cpp
new file mode 100644
index 0000000..95f067e
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-msg.cpp
@@ -0,0 +1,23 @@
+
+#include <bits/ensure.h>
+#include <sys/msg.h>
+
+int msgget(key_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int msgctl(int, int, struct msqid_ds *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t msgrcv(int, void *, size_t, long, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int msgsnd(int, const void *, size_t, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-resource-stubs.cpp b/lib/mlibc/options/posix/generic/sys-resource-stubs.cpp
new file mode 100644
index 0000000..597de4d
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-resource-stubs.cpp
@@ -0,0 +1,57 @@
+
+#include <errno.h>
+#include <sys/resource.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int getpriority(int which, id_t who) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getpriority, -1);
+	int value = 0;
+	if(int e = mlibc::sys_getpriority(which, who, &value); e) {
+		errno = e;
+	}
+	return value;
+}
+
+int setpriority(int which, id_t who, int prio) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setpriority, -1);
+	if(int e = mlibc::sys_setpriority(which, who, prio); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getrusage(int scope, struct rusage *usage) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getrusage, -1);
+	if(int e = mlibc::sys_getrusage(scope, usage); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getrlimit(int resource, struct rlimit *limit) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getrlimit, -1);
+	if(int e = mlibc::sys_getrlimit(resource, limit); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setrlimit(int resource, const struct rlimit *limit) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setrlimit, -1);
+	if(int e = mlibc::sys_setrlimit(resource, limit); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int prlimit(pid_t, int, const struct rlimit *, struct rlimit *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-select-stubs.cpp b/lib/mlibc/options/posix/generic/sys-select-stubs.cpp
new file mode 100644
index 0000000..e8ff927
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-select-stubs.cpp
@@ -0,0 +1,58 @@
+
+#include <string.h>
+#include <sys/select.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc-config.h>
+
+#include <mlibc/posix-sysdeps.hpp>
+
+void __FD_CLR(int fd, fd_set *set) {
+	__ensure(fd < FD_SETSIZE);
+	set->__mlibc_elems[fd / 8] &= ~(1 << (fd % 8));
+}
+int __FD_ISSET(int fd, fd_set *set) {
+	__ensure(fd < FD_SETSIZE);
+	return set->__mlibc_elems[fd / 8] & (1 << (fd % 8));
+}
+void __FD_SET(int fd, fd_set *set) {
+	__ensure(fd < FD_SETSIZE);
+	set->__mlibc_elems[fd / 8] |= 1 << (fd % 8);
+}
+void __FD_ZERO(fd_set *set) {
+	memset(set->__mlibc_elems, 0, sizeof(fd_set));
+}
+
+int select(int num_fds, fd_set *__restrict read_set, fd_set *__restrict write_set,
+		fd_set *__restrict except_set, struct timeval *__restrict timeout) {
+	int num_events = 0;
+	struct timespec timeouts = {};
+	struct timespec *timeout_ptr = NULL;
+	if (timeout) {
+		timeouts.tv_sec = timeout->tv_sec;
+		timeouts.tv_nsec = timeout->tv_usec * 1000;
+		timeout_ptr = &timeouts;
+	}
+
+    MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pselect, -1);
+	if(int e = mlibc::sys_pselect(num_fds, read_set, write_set, except_set,
+				timeout_ptr, NULL, &num_events); e) {
+		errno = e;
+		return -1;
+	}
+	return num_events;
+}
+
+int pselect(int num_fds, fd_set *read_set, fd_set *write_set, fd_set *except_set,
+		const struct timespec *timeout,	const sigset_t *sigmask) {
+	int num_events = 0;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pselect, -1);
+	if(int e = mlibc::sys_pselect(num_fds, read_set, write_set, except_set,
+				timeout, sigmask, &num_events); e) {
+		errno = e;
+		return -1;
+	}
+	return num_events;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-sem.cpp b/lib/mlibc/options/posix/generic/sys-sem.cpp
new file mode 100644
index 0000000..ac3df69
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-sem.cpp
@@ -0,0 +1,51 @@
+
+#include <bits/ensure.h>
+#include <errno.h>
+#include <limits.h>
+#include <sys/sem.h>
+
+#include <mlibc/posix-sysdeps.hpp>
+
+int semget(key_t key, int n, int fl) {
+	if(n > USHRT_MAX) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	int id = 0;
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_semget, -1);
+	if(int e = sysdep(key, n, fl, &id); e) {
+		errno = e;
+		return -1;
+	}
+	return id;
+}
+
+int semop(int, struct sembuf *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+union semun {
+	int val;
+	struct semid_ds *buf;
+	unsigned short *array;
+};
+
+int semctl(int id, int num, int cmd, ...) {
+	union semun semun;
+	int ret = 0;
+
+	va_list ap;
+	va_start(ap, cmd);
+	semun = va_arg(ap, union semun);
+	va_end(ap);
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_semctl, -1);
+	if(int e = sysdep(id, num, cmd, semun.buf, &ret); e) {
+		errno = e;
+		return -1;
+	}
+
+	return ret;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-shm.cpp b/lib/mlibc/options/posix/generic/sys-shm.cpp
new file mode 100644
index 0000000..3af7e90
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-shm.cpp
@@ -0,0 +1,24 @@
+#include <sys/shm.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+
+void *shmat(int, const void *, int) {
+	__ensure(!"Function is not implemented");
+	__builtin_unreachable();
+}
+
+int shmctl(int, int, struct shmid_ds *) {
+	__ensure(!"Function is not implemented");
+	__builtin_unreachable();
+}
+
+int shmdt(const void *) {
+	__ensure(!"Function is not implemented");
+	__builtin_unreachable();
+}
+
+int shmget(key_t, size_t, int) {
+	mlibc::infoLogger() << "mlibc: shmget() is a no-op!" << frg::endlog;
+	return -1;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-socket-stubs.cpp b/lib/mlibc/options/posix/generic/sys-socket-stubs.cpp
new file mode 100644
index 0000000..037a994
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-socket-stubs.cpp
@@ -0,0 +1,225 @@
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/socket.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int accept(int fd, struct sockaddr *__restrict addr_ptr, socklen_t *__restrict addr_length) {
+	int newfd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_accept, -1);
+	if(int e = mlibc::sys_accept(fd, &newfd, addr_ptr, addr_length, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return newfd;
+}
+
+int accept4(int fd, struct sockaddr *__restrict addr_ptr, socklen_t *__restrict addr_length, int flags) {
+	int newfd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_accept, -1);
+	if(int e = mlibc::sys_accept(fd, &newfd, addr_ptr, addr_length, flags); e) {
+		errno = e;
+		return -1;
+	}
+
+	return newfd;
+}
+
+int bind(int fd, const struct sockaddr *addr_ptr, socklen_t addr_len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_bind, -1);
+	if(int e = mlibc::sys_bind(fd, addr_ptr, addr_len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int connect(int fd, const struct sockaddr *addr_ptr, socklen_t addr_len) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_connect, -1);
+	if(int e = mlibc::sys_connect(fd, addr_ptr, addr_len); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getpeername(int fd, struct sockaddr *addr_ptr, socklen_t *__restrict addr_length) {
+	socklen_t actual_length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_peername, -1);
+	if(int e = mlibc::sys_peername(fd, addr_ptr, *addr_length, &actual_length); e) {
+		errno = e;
+		return -1;
+	}
+	*addr_length = actual_length;
+	return 0;
+}
+
+int getsockname(int fd, struct sockaddr *__restrict addr_ptr, socklen_t *__restrict addr_length) {
+	socklen_t actual_length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sockname, -1);
+	if(int e = mlibc::sys_sockname(fd, addr_ptr, *addr_length, &actual_length); e) {
+		errno = e;
+		return -1;
+	}
+	*addr_length = actual_length;
+	return 0;
+}
+
+int getsockopt(int fd, int layer, int number,
+		void *__restrict buffer, socklen_t *__restrict size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getsockopt, -1);
+	return mlibc::sys_getsockopt(fd, layer, number, buffer, size);
+}
+
+int listen(int fd, int backlog) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_listen, -1);
+	if(int e = mlibc::sys_listen(fd, backlog); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t recv(int sockfd, void *__restrict buf, size_t len, int flags) {
+	return recvfrom(sockfd, buf, len, flags, NULL, NULL);
+}
+
+ssize_t recvfrom(int sockfd, void *__restrict buf, size_t len, int flags,
+		struct sockaddr *__restrict src_addr, socklen_t *__restrict addrlen) {
+	if(mlibc::sys_recvfrom) {
+		ssize_t length;
+		if(int e = mlibc::sys_recvfrom(sockfd, buf, len, flags, src_addr, addrlen, &length); e) {
+			errno = e;
+			return -1;
+		}
+		return length;
+	}
+
+	struct iovec iov = {};
+	iov.iov_base = buf;
+	iov.iov_len = len;
+
+	struct msghdr hdr = {};
+	hdr.msg_name = src_addr;
+	if (addrlen) {
+		hdr.msg_namelen = *addrlen;
+	}
+	hdr.msg_iov = &iov;
+	hdr.msg_iovlen = 1;
+
+	int ret = recvmsg(sockfd, &hdr, flags);
+	if (ret < 0)
+		return ret;
+
+	if(addrlen)
+		*addrlen = hdr.msg_namelen;
+	return ret;
+}
+
+ssize_t recvmsg(int fd, struct msghdr *hdr, int flags) {
+	ssize_t length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_msg_recv, -1);
+	if(int e = mlibc::sys_msg_recv(fd, hdr, flags, &length); e) {
+		errno = e;
+		return -1;
+	}
+	return length;
+}
+
+int recvmmsg(int, struct mmsghdr *, unsigned int, int, struct timespec *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t send(int fd, const void *buffer, size_t size, int flags) {
+	return sendto(fd, buffer, size, flags, nullptr, 0);
+}
+
+ssize_t sendto(int fd, const void *buffer, size_t size, int flags,
+		const struct sockaddr *sock_addr, socklen_t addr_length) {
+	if(mlibc::sys_sendto) {
+		ssize_t length;
+		if(int e = mlibc::sys_sendto(fd, buffer, size, flags, sock_addr, addr_length, &length); e) {
+			errno = e;
+			return -1;
+		}
+		return length;
+	}
+
+	struct iovec iov = {};
+	iov.iov_base = const_cast<void *>(buffer);
+	iov.iov_len = size;
+
+	struct msghdr hdr = {};
+	hdr.msg_name = const_cast<struct sockaddr *>(sock_addr);
+	hdr.msg_namelen = addr_length;
+	hdr.msg_iov = &iov;
+	hdr.msg_iovlen = 1;
+
+	return sendmsg(fd, &hdr, flags);
+}
+
+ssize_t sendmsg(int fd, const struct msghdr *hdr, int flags) {
+	if(hdr->msg_iovlen > IOV_MAX)
+		return EMSGSIZE;
+
+	ssize_t length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_msg_send, -1);
+	if(int e = mlibc::sys_msg_send(fd, hdr, flags, &length); e) {
+		errno = e;
+		return -1;
+	}
+	return length;
+}
+
+int sendmmsg(int, struct mmsghdr *, unsigned int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int setsockopt(int fd, int layer, int number,
+		const void *buffer, socklen_t size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setsockopt, -1);
+	return mlibc::sys_setsockopt(fd, layer, number, buffer, size);
+}
+
+int shutdown(int sockfd, int how) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_shutdown, -1);
+	if(int e = sysdep(sockfd, how); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int sockatmark(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int socket(int family, int type, int protocol) {
+	int fd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_socket, -1);
+	if(int e = mlibc::sys_socket(family, type, protocol, &fd); e) {
+		errno = e;
+		return -1;
+	}
+	return fd;
+}
+
+int socketpair(int domain, int type, int protocol, int sv[2]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_socketpair, -1);
+	if(int e = mlibc::sys_socketpair(domain, type, protocol, sv); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// connectpair() is provided by the platform
+
diff --git a/lib/mlibc/options/posix/generic/sys-stat-stubs.cpp b/lib/mlibc/options/posix/generic/sys-stat-stubs.cpp
new file mode 100644
index 0000000..2eca445
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-stat-stubs.cpp
@@ -0,0 +1,155 @@
+
+#include <errno.h>
+#include <bits/ensure.h>
+#include <sys/stat.h>
+
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int chmod(const char *pathname, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_chmod, -1);
+	if(int e = mlibc::sys_chmod(pathname, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchmod(int fd, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchmod, -1);
+	if(int e = mlibc::sys_fchmod(fd, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchmodat, -1);
+	if(int e = mlibc::sys_fchmodat(dirfd, pathname, mode, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstatat(int dirfd, const char *path, struct stat *result, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::fd_path, dirfd, path, flags, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int futimens(int fd, const struct timespec times[2]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+
+	if (int e = mlibc::sys_utimensat(fd, nullptr, times, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int mkdir(const char *path, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mkdir, -1);
+	if(int e = mlibc::sys_mkdir(path, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mkdirat(int dirfd, const char *path, mode_t mode) {
+	mlibc::infoLogger() << "\e[31mmlibc: mkdirat() ignores its mode\e[39m" << frg::endlog;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mkdirat, -1);
+	if(int e = mlibc::sys_mkdirat(dirfd, path, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int mkfifo(const char *path, mode_t mode) {
+	return mkfifoat(AT_FDCWD, path, mode);
+}
+
+int mkfifoat(int dirfd, const char *path, mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mkfifoat, -1);
+	if (int e = mlibc::sys_mkfifoat(dirfd, path, mode); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int mknod(const char *path, mode_t mode, dev_t dev) {
+	return mknodat(AT_FDCWD, path, mode, dev);
+}
+
+int mknodat(int dirfd, const char *path, mode_t mode, dev_t dev) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_mknodat, -1);
+	if (int e = mlibc::sys_mknodat(dirfd, path, mode, dev); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+mode_t umask(mode_t mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_umask, -1);
+	mode_t old;
+	if (int e = mlibc::sys_umask(mode, &old); e) {
+		errno = e;
+		return -1;
+	}
+	return old;
+}
+
+int utimensat(int dirfd, const char *pathname, const struct timespec times[2], int flags) {
+	if(pathname == nullptr) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	if (int e = mlibc::sys_utimensat(dirfd, pathname, times, flags); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
+int stat(const char *path, struct stat *result) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::path, -1, path, 0, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int lstat(const char *path, struct stat *result) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::path,
+			-1, path, AT_SYMLINK_NOFOLLOW, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstat(int fd, struct stat *result) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_stat, -1);
+	if(int e = mlibc::sys_stat(mlibc::fsfd_target::fd, fd, "", 0, result); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-statvfs-stubs.cpp b/lib/mlibc/options/posix/generic/sys-statvfs-stubs.cpp
new file mode 100644
index 0000000..c02cc39
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-statvfs-stubs.cpp
@@ -0,0 +1,24 @@
+#include <errno.h>
+#include <sys/statvfs.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int statvfs(const char *path, struct statvfs *out) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_statvfs, -1);
+	if(int e = mlibc::sys_statvfs(path, out); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fstatvfs(int fd, struct statvfs *out) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fstatvfs, -1);
+	if(int e = mlibc::sys_fstatvfs(fd, out); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-time-stubs.cpp b/lib/mlibc/options/posix/generic/sys-time-stubs.cpp
new file mode 100644
index 0000000..5cc0fe5
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-time-stubs.cpp
@@ -0,0 +1,107 @@
+
+#include <errno.h>
+#include <sys/time.h>
+#include <time.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+
+int gettimeofday(struct timeval *__restrict result, void *__restrict unused) {
+	(void)unused; // Linux just ignores gettimeofday().
+
+	if(result) {
+		long nanos;
+		if(int e = mlibc::sys_clock_get(CLOCK_REALTIME, &result->tv_sec, &nanos); e) {
+			errno = e;
+			return -1;
+		}
+		result->tv_usec = nanos / 1000;
+	}
+	return 0;
+}
+
+int settimeofday(const struct timeval *, const struct timezone *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void timeradd(const struct timeval *a, const struct timeval *b, struct timeval *res) {
+	res->tv_sec = a->tv_sec + b->tv_sec;
+	res->tv_usec = a->tv_usec + b->tv_usec;
+	while(res->tv_usec > 999999) {
+		res->tv_usec -= 1000000;
+		res->tv_sec += 1;
+	}
+}
+
+void timersub(const struct timeval *a, const struct timeval *b, struct timeval *res) {
+	res->tv_sec = a->tv_sec - b->tv_sec;
+	res->tv_usec = a->tv_usec - b->tv_usec;
+	while(res->tv_usec < 0) {
+		res->tv_usec += 1000000;
+		res->tv_sec -= 1;
+	}
+}
+
+void timerclear(struct timeval *tvp) {
+	tvp->tv_sec = 0;
+	tvp->tv_usec = 0;
+}
+
+int timerisset(struct timeval *tvp) {
+	if(tvp->tv_sec != 0 || tvp->tv_usec != 0) {
+		return 1;
+	}
+	return 0;
+}
+
+int getitimer(int which, struct itimerval *curr_value) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getitimer, -1);
+	if(int e = mlibc::sys_getitimer(which, curr_value); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setitimer(int which, const struct itimerval *new_value, struct itimerval *old_value) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setitimer, -1);
+	if(int e = mlibc::sys_setitimer(which, new_value, old_value); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int timer_create(clockid_t clk, struct sigevent *__restrict evp, timer_t *__restrict res) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_timer_create, -1);
+	if(int e = mlibc::sys_timer_create(clk, evp, res); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int timer_settime(timer_t t, int flags, const struct itimerspec *__restrict val, struct itimerspec *__restrict old) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_timer_settime, -1);
+	if(int e = mlibc::sys_timer_settime(t, flags, val, old); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int timer_gettime(timer_t, struct itimerspec *) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int timer_delete(timer_t t) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_timer_delete, -1);
+	if(int e = mlibc::sys_timer_delete(t); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
diff --git a/lib/mlibc/options/posix/generic/sys-times.cpp b/lib/mlibc/options/posix/generic/sys-times.cpp
new file mode 100644
index 0000000..61b6e25
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-times.cpp
@@ -0,0 +1,19 @@
+
+#include <errno.h>
+#include <sys/times.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <internal-config.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+clock_t times(struct tms *tms) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_times, -1);
+	clock_t ret;
+	if(int e = mlibc::sys_times(tms, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	return ret;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-uio.cpp b/lib/mlibc/options/posix/generic/sys-uio.cpp
new file mode 100644
index 0000000..0f14bc0
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-uio.cpp
@@ -0,0 +1,67 @@
+
+#include <sys/uio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#include <frg/vector.hpp>
+#include <mlibc/allocator.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <bits/ensure.h>
+
+ssize_t readv(int fd, const struct iovec *iovs, int iovc) {
+	ssize_t read_bytes = 0;
+
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_readv, -1);
+
+	if (int e = sysdep(fd, iovs, iovc, &read_bytes); e) {
+		errno = e;
+		return -1;
+	}
+
+	return read_bytes;
+}
+
+ssize_t writev(int fd, const struct iovec *iovs, int iovc) {
+	__ensure(iovc);
+
+	ssize_t written = 0;
+	size_t bytes = 0;
+	for(int i = 0; i < iovc; i++) {
+		if(SSIZE_MAX - bytes < iovs[i].iov_len) {
+			errno = EINVAL;
+			return -1;
+		}
+		bytes += iovs[i].iov_len;
+	}
+	frg::vector<char, MemoryAllocator> buffer{getAllocator()};
+	buffer.resize(bytes);
+
+	size_t to_copy = bytes;
+	char *bp = buffer.data();
+	for(int i = 0; i < iovc; i++) {
+		size_t copy = frg::min(iovs[i].iov_len, to_copy);
+
+		bp = (char *)mempcpy((void *)bp, (void *)iovs[i].iov_base, copy);
+
+		to_copy -= copy;
+		if(to_copy == 0)
+			break;
+	}
+
+	written = write(fd, buffer.data(), bytes);
+	return written;
+}
+
+ssize_t preadv(int, const struct iovec *, int, off_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+ssize_t pwritev(int, const struct iovec *, int, off_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/sys-utsname.cpp b/lib/mlibc/options/posix/generic/sys-utsname.cpp
new file mode 100644
index 0000000..3176574
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-utsname.cpp
@@ -0,0 +1,24 @@
+
+#include <string.h>
+#include <sys/utsname.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/debug.hpp>
+#include <internal-config.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int uname(struct utsname *p) {
+	if (p == NULL) {
+		errno = EFAULT;
+		return -1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_uname, -1);
+	if(int e = mlibc::sys_uname(p); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/sys-wait-stubs.cpp b/lib/mlibc/options/posix/generic/sys-wait-stubs.cpp
new file mode 100644
index 0000000..6e7cc78
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/sys-wait-stubs.cpp
@@ -0,0 +1,52 @@
+
+#include <errno.h>
+#include <sys/wait.h>
+#include <bits/ensure.h>
+
+#include <mlibc/ansi-sysdeps.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/debug.hpp>
+
+int waitid(idtype_t idtype, id_t id, siginfo_t *info, int options) {
+	auto sysdep = MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitid, -1);
+	if(int e = sysdep(idtype, id, info, options); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t waitpid(pid_t pid, int *status, int flags) {
+	pid_t ret;
+	int tmp_status = 0;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitpid, -1);
+	if(int e = mlibc::sys_waitpid(pid, &tmp_status, flags, NULL, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	if(status) {
+		*status = tmp_status;
+	}
+	return ret;
+}
+
+pid_t wait(int *status) {
+	return waitpid(-1, status, 0);
+}
+
+pid_t wait3(int *status, int options, struct rusage *rusage) {
+	(void) rusage;
+	mlibc::infoLogger() << "\e[31mmlibc: wait3() is not implemented correctly\e[39m"
+		<< frg::endlog;
+	return waitpid(-1, status, options);
+}
+
+pid_t wait4(pid_t pid, int *status, int options, struct rusage *ru) {
+	pid_t ret;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_waitpid, -1);
+	if(int e = mlibc::sys_waitpid(pid, status, options, ru, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	return ret;
+}
diff --git a/lib/mlibc/options/posix/generic/syslog-stubs.cpp b/lib/mlibc/options/posix/generic/syslog-stubs.cpp
new file mode 100644
index 0000000..6a80ff9
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/syslog-stubs.cpp
@@ -0,0 +1,152 @@
+
+#include <syslog.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <time.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <bits/ensure.h>
+
+#include <frg/mutex.hpp>
+#include <mlibc/lock.hpp>
+#include <mlibc/debug.hpp>
+
+// This syslog implementation is largely taken from musl
+
+static char log_ident[32];
+static int log_options;
+static int log_facility = LOG_USER;
+static int log_fd = -1;
+static int log_opt;
+static int log_mask = 0xff;
+
+static int use_mlibc_logger = 0;
+static FutexLock __syslog_lock;
+
+static const struct sockaddr_un log_addr {AF_UNIX, "/dev/log"};
+
+void closelog(void) {
+	frg::unique_lock<FutexLock> holder { __syslog_lock };
+	close(log_fd);
+	log_fd = -1;
+}
+
+static void __openlog() {
+	log_fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+	if(log_fd >= 0) {
+		int ret = connect(log_fd, (const sockaddr *)&log_addr, sizeof log_addr);
+		if(ret) {
+			mlibc::infoLogger() << "\e[31mmlibc: syslog: connect returned an error, falling back to infoLogger\e[39m" << frg::endlog;
+			use_mlibc_logger = 1;
+		}
+	}
+}
+
+void openlog(const char *ident, int options, int facility) {
+	frg::unique_lock<FutexLock> holder { __syslog_lock };
+	if(ident) {
+		size_t n = strnlen(ident, sizeof log_ident - 1);
+		memcpy(log_ident, ident, n);
+		log_ident[n] = 0;
+	} else {
+		log_ident[0] = 0;
+	}
+	log_options = options;
+	log_facility = facility;
+
+	if((options & LOG_NDELAY) && log_fd < 0)
+		__openlog();
+}
+
+int setlogmask(int mask) {
+	int old_mask = log_mask;
+
+	log_mask = mask;
+
+	return old_mask;
+}
+
+static void _vsyslog(int priority, const char *message, va_list ap) {
+	auto is_lost_conn = [] (int e) {
+		return e == ECONNREFUSED || e == ECONNRESET || e == ENOTCONN || e == EPIPE;
+	};
+
+	if(!(priority & log_mask)) {
+		return;
+	}
+
+	char timebuf[16];
+	time_t now;
+	struct tm tm;
+	char buf[1024];
+	int errno_save = errno;
+	int pid;
+	int l, l2;
+	int hlen;
+	int fd;
+
+	if(log_fd < 0)
+		__openlog();
+
+	if(use_mlibc_logger) {
+		vsnprintf(buf, sizeof buf, message, ap);
+		mlibc::infoLogger() << "mlibc: syslog: " << buf << frg::endlog;
+		return;
+	}
+
+	if(!(priority & LOG_FACMASK))
+		priority |= log_facility;
+
+	now = time(NULL);
+	gmtime_r(&now, &tm);
+	strftime(timebuf, sizeof timebuf, "%b %e %T", &tm);
+
+	pid = (log_opt & LOG_PID) ? getpid() : 0;
+	l = snprintf(buf, sizeof buf, "<%d>%s %n%s%s%.0d%s: ",
+		priority, timebuf, &hlen, log_ident, "[" + !pid, pid, "]" + !pid);
+	errno = errno_save;
+	l2 = vsnprintf(buf + l, sizeof buf - l, message, ap);
+	if(l2 >= 0) {
+		if(l2 >= (long int)(sizeof buf - l))
+			l = sizeof buf - 1;
+		else
+			l += l2;
+		if(buf[l - 1] != '\n')
+			buf[l++] = '\n';
+		if(send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno)
+		    || connect(log_fd, (const sockaddr *)&log_addr, sizeof log_addr) < 0
+		    || send(log_fd, buf, l, 0) < 0)
+		    && (log_opt & LOG_CONS)) {
+			fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
+			if(fd >= 0) {
+				dprintf(fd, "%.*s", l - hlen, buf + hlen);
+				close(fd);
+			}
+		}
+		if(log_opt & LOG_PERROR)
+			dprintf(STDERR_FILENO, "%.*s", l - hlen, buf + hlen);
+	}
+}
+
+void syslog(int priority, const char *format, ...) {
+	va_list ap;
+	va_start(ap, format);
+	vsyslog(priority, format, ap);
+	va_end(ap);
+}
+
+void vsyslog(int priority, const char *message, va_list ap) {
+	int cs;
+	if(!(log_mask & LOG_MASK(priority & 7)) || (priority & ~0x3ff)) {
+		mlibc::infoLogger() << "\e[31mmlibc: syslog: log_mask or priority out of range, not printing anything\e[39m" << frg::endlog;
+		return;
+	}
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	frg::unique_lock<FutexLock> lock(__syslog_lock);
+	_vsyslog(priority, message, ap);
+	pthread_setcancelstate(cs, 0);
+}
diff --git a/lib/mlibc/options/posix/generic/termios-stubs.cpp b/lib/mlibc/options/posix/generic/termios-stubs.cpp
new file mode 100644
index 0000000..631456a
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/termios-stubs.cpp
@@ -0,0 +1,103 @@
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+
+#include <errno.h>
+#include <termios.h>
+#include <sys/ioctl.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+speed_t cfgetispeed(const struct termios *tios) {
+	return tios->c_cflag & CBAUD;
+}
+
+speed_t cfgetospeed(const struct termios *tios) {
+	return tios->c_cflag & CBAUD;
+}
+
+int cfsetispeed(struct termios *termios, speed_t speed) {
+	return speed ? cfsetospeed(termios, speed) : 0;
+}
+
+int cfsetospeed(struct termios *termios, speed_t speed) {
+	if(speed & ~CBAUD) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	termios->c_cflag &= ~CBAUD;
+	termios->c_cflag |= speed;
+
+	return 0;
+}
+
+void cfmakeraw(struct termios *t) {
+	t->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+	t->c_oflag &= ~OPOST;
+	t->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+	t->c_cflag &= ~(CSIZE | PARENB);
+	t->c_cflag |= CS8;
+	t->c_cc[VMIN] = 1;
+	t->c_cc[VTIME] = 0;
+}
+
+int tcdrain(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcdrain, -1);
+	if(int e = mlibc::sys_tcdrain(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int tcflow(int fd, int action) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcflow, -1);
+	if(int e = mlibc::sys_tcflow(fd, action); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int tcflush(int fd, int queue_selector) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcflush, -1);
+	if(int e = mlibc::sys_tcflush(fd, queue_selector); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int tcgetattr(int fd, struct termios *attr) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcgetattr, -1);
+	if(int e = mlibc::sys_tcgetattr(fd, attr); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t tcgetsid(int fd) {
+	int sid;
+	if(ioctl(fd, TIOCGSID, &sid) < 0) {
+		return -1;
+	}
+	return sid;
+}
+
+int tcsendbreak(int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int tcsetattr(int fd, int opts, const struct termios *attr) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_tcsetattr, -1);
+	if(int e = mlibc::sys_tcsetattr(fd, opts, attr); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/time.cpp b/lib/mlibc/options/posix/generic/time.cpp
new file mode 100644
index 0000000..14193af
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/time.cpp
@@ -0,0 +1,505 @@
+#include <ctype.h>
+#include <langinfo.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include <bits/ensure.h>
+#include <mlibc/strings.hpp>
+
+namespace {
+
+int month_to_day(int month) {
+	switch(month){
+		case  0: return 0;
+		case  1: return 31;
+		case  2: return 59;
+		case  3: return 90;
+		case  4: return 120;
+		case  5: return 151;
+		case  6: return 181;
+		case  7: return 212;
+		case  8: return 243;
+		case  9: return 273;
+		case 10: return 304;
+		case 11: return 334;
+	}
+	return -1;
+}
+
+int is_leapyear(int year) {
+	return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
+}
+
+int month_and_year_to_day_in_year(int month, int year){
+	int day = month_to_day(month);
+	if(is_leapyear(year) && month < 2)
+		return day + 1;
+
+	return day;
+}
+
+int target_determination(int month) {
+	switch(month){
+		case 0: return 3;
+		case 1: return 14;
+		case 2: return 14;
+		case 3: return 4;
+		case 4: return 9;
+		case 5: return 6;
+		case 6: return 11;
+		case 7: return 8;
+		case 8: return 5;
+		case 9: return 10;
+		case 10: return 7;
+		case 11: return 12;
+	}
+
+	return -1;
+}
+
+int doom_determination(int full_year) {
+	int century = full_year / 100;
+	int anchor = 2 + 5 * (century % 4) % 7;
+
+	int year = full_year % 100;
+
+	if(year % 2)
+		year += 11;
+
+	year /= 2;
+
+	if(year % 2)
+		year += 11;
+
+	return 7 - (year % 7) + anchor;
+}
+
+//Determine day of week through the doomsday algorithm.
+int day_determination(int day, int month, int year) {
+	int doom = doom_determination(year);
+	bool leap = is_leapyear(year);
+
+	int target = target_determination(month);
+	if(leap && month < 2)
+		target++;
+
+	int doom_dif = (day - target) % 7;
+	return (doom + doom_dif) % 7;
+}
+
+struct strptime_internal_state {
+	bool has_century;
+	bool has_year;
+	bool has_month;
+	bool has_day_of_month;
+	bool has_day_of_year;
+	bool has_day_of_week;
+
+	bool full_year_given;
+
+	int century;
+
+	size_t format_index;
+	size_t input_index;
+};
+
+char *strptime_internal(const char *__restrict input, const char *__restrict format,
+	struct tm *__restrict tm, struct strptime_internal_state *__restrict state) {
+	auto matchLanginfoItem = [&] (int start, size_t num, int &dest, bool &flag) -> bool {
+		for(size_t i = start; i < (start + num); i++) {
+			const char *mon = nl_langinfo(i);
+			size_t len = strlen(mon);
+			if(mlibc::strncasecmp(&input[state->input_index], mon, len))
+				continue;
+			state->input_index += len;
+			dest = i - start;
+			flag = true;
+			return true;
+		}
+		return false;
+	};
+
+	auto matchNumericRange = [&] (int start, int end, int &dest, bool *flag) -> bool {
+		int product = 0, n = 0;
+		sscanf(&input[state->input_index], "%d%n", &product, &n);
+		if(n == 0 || 2 < n)
+			return false;
+		if(product < start || product > end)
+			return false;
+		state->input_index += n;
+		dest = product;
+		if(flag) *flag = true;
+		return true;
+	};
+
+	while(isspace(input[state->input_index]))
+		state->input_index++;
+
+	if(input[state->input_index] == '\0')
+		return NULL;
+
+	while(format[state->format_index] != '\0'){
+		if(format[state->format_index] != '%'){
+			if(isspace(format[state->format_index])){
+				while(isspace(input[state->input_index++]));
+				state->input_index--;
+			}
+			else {
+				if(format[state->format_index] != input[state->input_index++])
+					return NULL;
+			}
+			state->format_index++;
+			continue;
+		}
+		state->format_index++;
+		switch(format[state->format_index]){
+			case '%':
+				if(input[state->input_index++] != '%')
+					return NULL;
+				break;
+			case 'a':
+			case 'A': {
+				if (!matchLanginfoItem(DAY_1, 7, tm->tm_wday, state->has_day_of_week) && \
+					!matchLanginfoItem(ABDAY_1, 7, tm->tm_wday, state->has_day_of_week))
+					return NULL;
+				break;
+			}
+			case 'b':
+			case 'B':
+			case 'h': {
+				if (!matchLanginfoItem(MON_1, 12, tm->tm_mon, state->has_month) && \
+					!matchLanginfoItem(ABMON_1, 12, tm->tm_mon, state->has_month))
+					return NULL;
+				break;
+			}
+			case 'c':
+				__ensure(!"strptime() %c directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'C': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 2 < n)
+					return NULL;
+				state->input_index += n;
+				state->century = product;
+				state->has_century = true;
+				break;
+			}
+			case 'd': //`%d` and `%e` are equivalent
+			case 'e': {
+				if(!matchNumericRange(1, 31, tm->tm_mday, &state->has_day_of_month))
+					return NULL;
+				break;
+			}
+			case 'D': { //equivalent to `%m/%d/%y`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%m/%d/%y", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'H': {
+				if(!matchNumericRange(0, 23, tm->tm_hour, nullptr))
+					return NULL;
+				break;
+			}
+			case 'I': {
+				if(!matchNumericRange(1, 12, tm->tm_hour, nullptr))
+					return NULL;
+				break;
+			}
+			case 'j': {
+				if(!matchNumericRange(1, 366, tm->tm_yday, &state->has_day_of_year))
+					return NULL;
+				tm->tm_yday--;
+				break;
+			}
+			case 'm': {
+				if(!matchNumericRange(1, 12, tm->tm_mon, &state->has_month))
+					return NULL;
+				tm->tm_mon--;
+				break;
+			}
+			case 'M': {
+				if(!matchNumericRange(0, 59, tm->tm_min, nullptr))
+					return NULL;
+				break;
+			}
+			case 'n':
+			case 't': {
+				size_t n = 0;
+				while(isspace(input[state->input_index++]))
+					n++;
+				if(n == 0)
+					return NULL;
+				state->input_index--;
+				break;
+			}
+			case 'p': {
+				const char *meridian_str = nl_langinfo(AM_STR);
+				size_t len = strlen(meridian_str);
+				if (!mlibc::strncasecmp(&input[state->input_index], meridian_str, len)) {
+					tm->tm_hour %= 12;
+					state->input_index += len;
+					break;
+				}
+				meridian_str = nl_langinfo(PM_STR);
+				len = strlen(meridian_str);
+				if (!mlibc::strncasecmp(&input[state->input_index], meridian_str, len)) {
+					tm->tm_hour %= 12;
+					tm->tm_hour += 12;
+					state->input_index += len;
+					break;
+				}
+				break;
+			}
+			case 'r': {  //equivalent to `%I:%M:%S %p`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%I:%M:%S %p", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'R': { //equivalent to `%H:%M`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%H:%M", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'S': {
+				if(!matchNumericRange(0, 60, tm->tm_sec, nullptr))
+					return NULL;
+				break;
+			}
+			case 'T': { //equivalent to `%H:%M:%S`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%H:%M:%S", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'U':
+				__ensure(!"strptime() %U directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'w': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 1 < n)
+					return NULL;
+				state->input_index += n;
+				tm->tm_wday = product;
+				state->has_day_of_week = true;
+				break;
+			}
+			case 'W':
+				__ensure(!"strptime() %W directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'x':
+				__ensure(!"strptime() %x directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'X':
+				__ensure(!"strptime() %X directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'y': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 2 < n)
+					return NULL;
+				if(product < 69)
+					product += 100;
+				state->input_index += n;
+				tm->tm_year = product;
+				state->has_year = true;
+				break;
+			}
+			case 'Y': {
+				int product = 0, n = 0;
+				sscanf(&input[state->input_index], "%d%n", &product, &n);
+				if(n == 0 || 4 < n)
+					return NULL;
+				state->input_index += n;
+				tm->tm_year = product - 1900;
+				state->has_year = true;
+				state->has_century = true;
+				state->full_year_given = true;
+				state->century = product / 100;
+				break;
+			}
+			case 'F': { //GNU extensions
+				//equivalent to `%Y-%m-%d`
+				size_t pre_fi = state->format_index;
+				state->format_index = 0;
+
+				char *result = strptime_internal(input, "%Y-%m-%d", tm, state);
+				if(result == NULL)
+					return NULL;
+
+				state->format_index = pre_fi;
+				break;
+			}
+			case 'g':
+				__ensure(!"strptime() %g directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'G':
+				__ensure(!"strptime() %G directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'u': {
+				if(!matchNumericRange(1, 7, tm->tm_wday, nullptr))
+					return NULL;
+				tm->tm_wday--;
+				break;
+			}
+			case 'V':
+				__ensure(!"strptime() %V directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'z':
+				__ensure(!"strptime() %z directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'Z':
+				__ensure(!"strptime() %Z directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 's': //end of GNU extensions
+				__ensure(!"strptime() %s directive unimplemented.");
+				__builtin_unreachable();
+				break;
+			case 'E': { //locale-dependent date & time representation
+				__ensure(!"strptime() %E* directives unimplemented.");
+				__builtin_unreachable();
+				/*
+				state->format_index++;
+				switch(format[state->format_index]){
+					case 'c':
+						break;
+					case 'C':
+						break;
+					case 'x':
+						break;
+					case 'X':
+						break;
+					case 'y':
+						break;
+					case 'Y':
+						break;
+					default:
+						return NULL;
+				}
+				*/
+			}
+			case 'O': { //locale-dependent numeric symbols
+				__ensure(!"strptime() %O* directives unimplemented.");
+				__builtin_unreachable();
+				/*
+				state->format_index++;
+				switch(format[state->format_index]){
+					case 'd':
+					case 'e':
+						break;
+					case 'H':
+						break;
+					case 'I':
+						break;
+					case 'm':
+						break;
+					case 'M':
+						break;
+					case 'S':
+						break;
+					case 'U':
+						break;
+					case 'w':
+						break;
+					case 'W':
+						break;
+					case 'y':
+						break;
+					default:
+						return NULL;
+				}
+				*/
+			}
+			default:
+				return NULL;
+		}
+		state->format_index++;
+	}
+
+	return (char*)input + state->input_index;
+}
+
+} //anonymous namespace
+
+char *strptime(const char *__restrict s, const char *__restrict format, struct tm *__restrict tm){
+	struct strptime_internal_state state = {};
+
+	char *result = strptime_internal(s, format, tm, &state);
+
+	if(result == NULL)
+		return NULL;
+
+	if(state.has_century && !state.full_year_given){
+		int full_year = state.century * 100;
+
+		if(state.has_year){
+			//Compensate for default century-adjustment of `%j` operand
+			if(tm->tm_year >= 100)
+				full_year += tm->tm_year - 100;
+			else
+				full_year += tm->tm_year;
+		}
+
+		tm->tm_year = full_year - 1900;
+
+		state.has_year = true;
+	}
+
+	if(state.has_month && !state.has_day_of_year){
+		int day = 0;
+		if(state.has_year)
+			day = month_and_year_to_day_in_year(tm->tm_mon, tm->tm_year);
+		else
+			day = month_to_day(tm->tm_mon);
+
+		tm->tm_yday = day + tm->tm_mday - 1;
+		state.has_day_of_year = true;
+	}
+
+	if(state.has_year && !state.has_day_of_week){
+		if(!state.has_month && !state.has_day_of_month){
+			tm->tm_wday = day_determination(0, 0, tm->tm_year + 1900);
+		}
+		else if(state.has_month && state.has_day_of_month){
+			tm->tm_wday = day_determination(tm->tm_mday, tm->tm_mon, tm->tm_year + 1900);
+		}
+		state.has_day_of_week = true;
+	}
+
+	return result;
+}
diff --git a/lib/mlibc/options/posix/generic/ucontext-stubs.cpp b/lib/mlibc/options/posix/generic/ucontext-stubs.cpp
new file mode 100644
index 0000000..9413a78
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/ucontext-stubs.cpp
@@ -0,0 +1,19 @@
+#include <ucontext.h>
+#include <bits/ensure.h>
+
+int getcontext(ucontext_t *) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
+int setcontext(const ucontext_t *) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
+void makecontext(ucontext_t *, void (*)(), int, ...) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
+int swapcontext(ucontext_t *, const ucontext_t *) {
+	__ensure(!"Not implemented!");
+	__builtin_unreachable();
+}
diff --git a/lib/mlibc/options/posix/generic/unistd-stubs.cpp b/lib/mlibc/options/posix/generic/unistd-stubs.cpp
new file mode 100644
index 0000000..39cf76a
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/unistd-stubs.cpp
@@ -0,0 +1,1227 @@
+#include <stdio.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <unistd.h>
+#include <limits.h>
+#include <termios.h>
+#include <pwd.h>
+#include <sys/ioctl.h>
+
+#include <bits/ensure.h>
+#include <mlibc/allocator.hpp>
+#include <mlibc/arch-defs.hpp>
+#include <mlibc/debug.hpp>
+#include <mlibc/posix-sysdeps.hpp>
+#include <mlibc/bsd-sysdeps.hpp>
+#include <mlibc/thread.hpp>
+
+namespace {
+
+constexpr bool logExecvpeTries = false;
+
+}
+
+unsigned int alarm(unsigned int seconds) {
+	struct itimerval it = {}, old = {};
+	it.it_value.tv_sec = seconds;
+	setitimer(ITIMER_REAL, &it, &old);
+	return old.it_value.tv_sec + !! old.it_value.tv_usec;
+}
+
+int chdir(const char *path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_chdir, -1);
+	if(int e = mlibc::sys_chdir(path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchdir(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchdir, -1);
+	if(int e = mlibc::sys_fchdir(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int chown(const char *path, uid_t uid, gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(AT_FDCWD, path, uid, gid, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t confstr(int name, char *buf, size_t len) {
+	const char *str = "";
+	if (name == _CS_PATH) {
+		str = "/bin:/usr/bin";
+	} else if(name == _CS_GNU_LIBPTHREAD_VERSION) {
+		// We are not glibc, so we can return 0 here.
+		return 0;
+	} else if(name == _CS_GNU_LIBC_VERSION) {
+		// We are not glibc, so we can return 0 here.
+		return 0;
+	} else {
+		mlibc::infoLogger() << "\e[31mmlibc: confstr() request " << name << " is unimplemented\e[39m"
+				<< frg::endlog;
+		__ensure(!"Not implemented");
+	}
+
+	return snprintf(buf, len, "%s", str) + 1;
+}
+
+void _exit(int status) {
+	mlibc::sys_exit(status);
+}
+
+int execl(const char *path, const char *arg0, ...) {
+	// TODO: It's a stupid idea to limit the number of arguments here.
+	char *argv[16];
+	argv[0] = const_cast<char *>(arg0);
+
+	va_list args;
+	int n = 1;
+	va_start(args, arg0);
+	while(true) {
+		__ensure(n < 15);
+		auto argn = va_arg(args, const char *);
+		argv[n++] = const_cast<char *>(argn);
+		if(!argn)
+			break;
+	}
+	va_end(args);
+	argv[n] = nullptr;
+
+	return execve(path, argv, environ);
+}
+
+// This function is taken from musl.
+int execle(const char *path, const char *arg0, ...) {
+	int argc;
+	va_list ap;
+	va_start(ap, arg0);
+	for(argc = 1; va_arg(ap, const char *); argc++);
+	va_end(ap);
+
+	int i;
+	char *argv[argc + 1];
+	char **envp;
+	va_start(ap, arg0);
+	argv[0] = (char *)argv;
+	for(i = 1; i <= argc; i++)
+		argv[i] = va_arg(ap, char *);
+	envp = va_arg(ap, char **);
+	va_end(ap);
+	return execve(path, argv, envp);
+}
+
+// This function is taken from musl
+int execlp(const char *file, const char *argv0, ...) {
+	int argc;
+	va_list ap;
+	va_start(ap, argv0);
+	for(argc = 1; va_arg(ap, const char *); argc++);
+	va_end(ap);
+	{
+		int i;
+		char *argv[argc + 1];
+		va_start(ap, argv0);
+		argv[0] = (char *)argv0;
+		for(i = 1; i < argc; i++)
+			argv[i] = va_arg(ap, char *);
+		argv[i] = NULL;
+		va_end(ap);
+		return execvp(file, argv);
+	}
+}
+
+int execv(const char *path, char *const argv[]) {
+	return execve(path, argv, environ);
+}
+
+int execvp(const char *file, char *const argv[]) {
+	return execvpe(file, argv, environ);
+}
+
+int execvpe(const char *file, char *const argv[], char *const envp[]) {
+	char *null_list[] = {
+		nullptr
+	};
+
+	if(!argv)
+		argv = null_list;
+	if(!envp)
+		envp = null_list;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_execve, -1);
+
+	if(strchr(file, '/')) {
+		int e = mlibc::sys_execve(file, argv, envp);
+		__ensure(e && "sys_execve() is supposed to never return with success");
+		errno = e;
+		return -1;
+	}
+
+	frg::string_view dirs;
+	if(const char *pv = getenv("PATH"); pv) {
+		dirs = pv;
+	}else{
+		dirs = "/bin:/usr/bin";
+	}
+
+	size_t p = 0;
+	int res = ENOENT;
+	while(p < dirs.size()) {
+		size_t s; // Offset of next colon or end of string.
+		if(size_t cs = dirs.find_first(':', p); cs != size_t(-1)) {
+			s = cs;
+		}else{
+			s = dirs.size();
+		}
+
+		frg::string<MemoryAllocator> path{getAllocator()};
+		path += dirs.sub_string(p, s - p);
+		path += "/";
+		path += file;
+
+		if(logExecvpeTries)
+			mlibc::infoLogger() << "mlibc: execvpe() tries '" << path.data() << "'" << frg::endlog;
+
+		int e = mlibc::sys_execve(path.data(), argv, envp);
+		__ensure(e && "sys_execve() is supposed to never return with success");
+		switch(e) {
+		case ENOENT:
+		case ENOTDIR:
+			break;
+		case EACCES:
+			res = EACCES;
+			break;
+		default:
+			errno = e;
+			return -1;
+		}
+
+		p = s + 1;
+	}
+
+	errno = res;
+	return -1;
+}
+
+int faccessat(int dirfd, const char *pathname, int mode, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_faccessat, -1);
+	if(int e = mlibc::sys_faccessat(dirfd, pathname, mode, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchown(int fd, uid_t uid, gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(fd, "", uid, gid, AT_EMPTY_PATH); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fchownat(int fd, const char *path, uid_t uid, gid_t gid, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(fd, path, uid, gid, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fdatasync(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fdatasync, -1);
+	if(int e = mlibc::sys_fdatasync(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int fexecve(int, char *const [], char *const []) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+long fpathconf(int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int fsync(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fsync, -1);
+	if(auto e = mlibc::sys_fsync(fd); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int ftruncate(int fd, off_t size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ftruncate, -1);
+	if(int e = mlibc::sys_ftruncate(fd, size); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+char *getcwd(char *buffer, size_t size) {
+	if (buffer) {
+		if (size == 0) {
+			errno = EINVAL;
+			return NULL;
+		}
+	} else if (!buffer) {
+		if (size == 0)
+			size = PATH_MAX;
+
+		buffer = (char *)malloc(size);
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getcwd, nullptr);
+	if(int e = mlibc::sys_getcwd(buffer, size); e) {
+		errno = e;
+		return NULL;
+	}
+
+	return buffer;
+}
+
+int getgroups(int size, gid_t list[]) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getgroups, -1);
+	int ret;
+	if(int e = mlibc::sys_getgroups(size, list, &ret); e) {
+		errno = e;
+		return -1;
+	}
+	return ret;
+}
+
+long gethostid(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int gethostname(char *buffer, size_t bufsize) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_gethostname, -1);
+	if(auto e = mlibc::sys_gethostname(buffer, bufsize); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int sethostname(const char *buffer, size_t bufsize) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_sethostname, -1);
+	if(auto e = mlibc::sys_sethostname(buffer, bufsize); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// Code taken from musl
+char *getlogin(void) {
+	return getenv("LOGNAME");
+}
+
+int getlogin_r(char *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// optarg and optind are provided to us by the GLIBC part of the mlibc.
+
+static char *scan = NULL; /* Private scan pointer. */
+
+int getopt(int argc, char *const argv[], const char *optstring) {
+	char c;
+	char *place;
+
+	optarg = NULL;
+
+	if (!scan || *scan == '\0') {
+		if (optind == 0)
+			optind++;
+
+		if (optind >= argc || argv[optind][0] != '-' || argv[optind][1] == '\0')
+			return EOF;
+		if (argv[optind][1] == '-' && argv[optind][2] == '\0') {
+			optind++;
+			return EOF;
+		}
+
+		scan = argv[optind]+1;
+		optind++;
+	}
+
+	c = *scan++;
+	place = strchr(optstring, c);
+
+	if (!place || c == ':') {
+		fprintf(stderr, "%s: unknown option -%c\n", argv[0], c);
+		return '?';
+	}
+
+	place++;
+	if (*place == ':') {
+		if (*scan != '\0') {
+			optarg = scan;
+			scan = NULL;
+		} else if( optind < argc ) {
+			optarg = argv[optind];
+			optind++;
+		} else {
+			fprintf(stderr, "%s: option requires argument -%c\n", argv[0], c);
+			return ':';
+		}
+	}
+
+	return c;
+}
+
+pid_t getpgid(pid_t pid) {
+	pid_t pgid;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getpgid, -1);
+	if(int e = mlibc::sys_getpgid(pid, &pgid); e) {
+		errno = e;
+		return -1;
+	}
+	return pgid;
+}
+
+pid_t getpgrp(void) {
+	return getpgid(0);
+}
+
+pid_t getsid(pid_t pid) {
+	if(!mlibc::sys_getsid) {
+		MLIBC_MISSING_SYSDEP();
+		return -1;
+	}
+	pid_t sid;
+	if(int e = mlibc::sys_getsid(pid, &sid); e) {
+		errno = e;
+		return -1;
+	}
+	return sid;
+}
+
+int lchown(const char *path, uid_t uid, gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fchownat, -1);
+	if(int e = mlibc::sys_fchownat(AT_FDCWD, path, uid, gid, AT_SYMLINK_NOFOLLOW); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int link(const char *old_path, const char *new_path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_link, -1);
+	if(int e = mlibc::sys_link(old_path, new_path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int linkat(int olddirfd, const char *old_path, int newdirfd, const char *new_path, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_linkat, -1);
+	if(int e = mlibc::sys_linkat(olddirfd, old_path, newdirfd, new_path, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+// Code take from musl
+int lockf(int fd, int op, off_t size) {
+	struct flock l = {
+		.l_type = F_WRLCK,
+		.l_whence = SEEK_CUR,
+		.l_start = 0,
+		.l_len = size,
+		.l_pid = 0,
+	};
+
+	switch(op) {
+		case F_TEST:
+			l.l_type = F_RDLCK;
+			if(fcntl(fd, F_GETLK, &l) < 0)
+				return -1;
+			if(l.l_type == F_UNLCK || l.l_pid == getpid())
+				return 0;
+			errno = EACCES;
+			return -1;
+		case F_ULOCK:
+			l.l_type = F_UNLCK;
+			[[fallthrough]];
+		case F_TLOCK:
+			return fcntl(fd, F_SETLK, &l);
+		case F_LOCK:
+			return fcntl(fd, F_SETLKW, &l);
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+int nice(int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+long pathconf(const char *, int name) {
+	switch (name) {
+	case _PC_NAME_MAX:
+		return NAME_MAX;
+	default:
+		mlibc::infoLogger() << "missing pathconf() entry " << name << frg::endlog;
+		errno = EINVAL;
+		return -1;
+	}
+}
+
+int pause(void) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pause, -1);
+	if(int e = mlibc::sys_pause(); e) {
+		errno = e;
+		return -1;
+	}
+	__ensure(!"There is no successful completion return value for pause");
+	__builtin_unreachable();
+}
+
+int pipe(int *fds) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pipe, -1);
+	if(int e = mlibc::sys_pipe(fds, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int pipe2(int *fds, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pipe, -1);
+	if(int e = mlibc::sys_pipe(fds, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t pread(int fd, void *buf, size_t n, off_t off) {
+	ssize_t num_read;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pread, -1);
+	if(int e = mlibc::sys_pread(fd, buf, n, off, &num_read); e) {
+		errno = e;
+		return -1;
+	}
+	return num_read;
+}
+
+ssize_t pwrite(int fd, const void *buf, size_t n, off_t off) {
+	ssize_t num_written;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_pwrite, -1);
+	if(int e = mlibc::sys_pwrite(fd, buf, n, off, &num_written); e) {
+		errno = e;
+		return -1;
+	}
+	return num_written;
+}
+
+ssize_t readlink(const char *__restrict path, char *__restrict buffer, size_t max_size) {
+	ssize_t length;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_readlink, -1);
+	if(int e = mlibc::sys_readlink(path, buffer, max_size, &length); e) {
+		errno = e;
+		return -1;
+	}
+	return length;
+}
+
+ssize_t readlinkat(int, const char *__restrict, char *__restrict, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int rmdir(const char *path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_rmdir, -1);
+	if(int e = mlibc::sys_rmdir(path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setegid(gid_t egid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setegid, 0);
+	if(int e = mlibc::sys_setegid(egid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int seteuid(uid_t euid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_seteuid, 0);
+	if(int e = mlibc::sys_seteuid(euid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setgid(gid_t gid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setgid, 0);
+	if(int e = mlibc::sys_setgid(gid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setpgid(pid_t pid, pid_t pgid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setpgid, -1);
+	if(int e = mlibc::sys_setpgid(pid, pgid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t setpgrp(void) {
+	return setpgid(0, 0);
+}
+
+int setregid(gid_t rgid, gid_t egid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setregid, -1);
+	if(int e = mlibc::sys_setregid(rgid, egid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setreuid(uid_t ruid, uid_t euid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setreuid, -1);
+	if(int e = mlibc::sys_setreuid(ruid, euid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+pid_t setsid(void) {
+	if(!mlibc::sys_setsid) {
+		MLIBC_MISSING_SYSDEP();
+		return -1;
+	}
+	pid_t sid;
+	if(int e = mlibc::sys_setsid(&sid); e) {
+		errno = e;
+		return -1;
+	}
+	return sid;
+}
+
+int setuid(uid_t uid) {
+	if(!mlibc::sys_setuid) {
+		MLIBC_MISSING_SYSDEP();
+		mlibc::infoLogger() << "mlibc: missing sysdep sys_setuid(). Returning 0" << frg::endlog;
+		return 0;
+	}
+	if(int e = mlibc::sys_setuid(uid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+void swab(const void *__restrict, void *__restrict, ssize_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int symlink(const char *target_path, const char *link_path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_symlink, -1);
+	if(int e = mlibc::sys_symlink(target_path, link_path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int symlinkat(const char *target_path, int dirfd, const char *link_path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_symlinkat, -1);
+	if(int e = mlibc::sys_symlinkat(target_path, dirfd, link_path); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+void sync(void) {
+	if(!mlibc::sys_sync) {
+		MLIBC_MISSING_SYSDEP();
+	} else {
+		mlibc::sys_sync();
+	}
+}
+
+long sysconf(int number) {
+	if(mlibc::sys_sysconf) {
+		long ret = 0;
+
+		int e = mlibc::sys_sysconf(number, &ret);
+
+		if(e && e != EINVAL) {
+			errno = e;
+			return -1;
+		}
+
+		if(e != EINVAL) {
+			return ret;
+		}
+	}
+
+	/* default return values, if not overriden by sysdep */
+	switch(number) {
+		case _SC_ARG_MAX:
+			// On linux, it is defined to 2097152 in most cases, so define it to be 2097152
+			return 2097152;
+		case _SC_PAGE_SIZE:
+			return mlibc::page_size;
+		case _SC_OPEN_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_OPEN_MAX) returns fallback value 256\e[39m" << frg::endlog;
+			return 256;
+		case _SC_PHYS_PAGES:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_PHYS_PAGES) returns fallback value 1024\e[39m" << frg::endlog;
+			return 1024;
+		case _SC_NPROCESSORS_ONLN:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_NPROCESSORS_ONLN) returns fallback value 1\e[39m" << frg::endlog;
+			return 1;
+		case _SC_GETPW_R_SIZE_MAX:
+			return NSS_BUFLEN_PASSWD;
+		case _SC_GETGR_R_SIZE_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_GETGR_R_SIZE_MAX) returns fallback value 1024\e[39m" << frg::endlog;
+			return 1024;
+		case _SC_CHILD_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_CHILD_MAX) returns fallback value 25\e[39m" << frg::endlog;
+			// On linux, it is defined to 25 in most cases, so define it to be 25
+			return 25;
+		case _SC_JOB_CONTROL:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_JOB_CONTROL) returns fallback value 1\e[39m" << frg::endlog;
+			// If 1, job control is supported
+			return 1;
+		case _SC_CLK_TCK:
+			// TODO: This should be obsolete?
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_CLK_TCK) is obsolete and returns arbitrary value 1000000\e[39m" << frg::endlog;
+			return 1000000;
+		case _SC_NGROUPS_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_NGROUPS_MAX) returns fallback value 65536\e[39m" << frg::endlog;
+			// On linux, it is defined to 65536 in most cases, so define it to be 65536
+			return 65536;
+		case _SC_RE_DUP_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_RE_DUP_MAX) returns fallback value RE_DUP_MAX\e[39m" << frg::endlog;
+			return RE_DUP_MAX;
+		case _SC_LINE_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_LINE_MAX) returns fallback value 2048\e[39m" << frg::endlog;
+			// Linux defines it as 2048.
+			return 2048;
+		case _SC_XOPEN_CRYPT:
+#if __MLIBC_CRYPT_OPTION
+			return _XOPEN_CRYPT;
+#else
+			return -1;
+#endif /* __MLIBC_CRYPT_OPTION */
+		case _SC_NPROCESSORS_CONF:
+			// TODO: actually return a proper value for _SC_NPROCESSORS_CONF
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_NPROCESSORS_CONF) unconditionally returns fallback value 1\e[39m" << frg::endlog;
+			return 1;
+		case _SC_HOST_NAME_MAX:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf(_SC_HOST_NAME_MAX) unconditionally returns fallback value 256\e[39m" << frg::endlog;
+			return 256;
+		default:
+			mlibc::infoLogger() << "\e[31mmlibc: sysconf() call is not implemented, number: " << number << "\e[39m" << frg::endlog;
+			errno = EINVAL;
+			return -1;
+	}
+}
+
+pid_t tcgetpgrp(int fd) {
+	int pgrp;
+	if(ioctl(fd, TIOCGPGRP, &pgrp) < 0) {
+		return -1;
+	}
+	return pgrp;
+}
+
+int tcsetpgrp(int fd, pid_t pgrp) {
+	return ioctl(fd, TIOCSPGRP, &pgrp);
+}
+
+int truncate(const char *, off_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+char *ttyname(int fd) {
+	const size_t size = 128;
+	static thread_local char buf[size];
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ttyname, nullptr);
+	if(int e = mlibc::sys_ttyname(fd, buf, size); e) {
+		errno = e;
+		return nullptr;
+	}
+	return buf;
+}
+
+int ttyname_r(int fd, char *buf, size_t size) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_ttyname, -1);
+	if(int e = mlibc::sys_ttyname(fd, buf, size); e) {
+		return e;
+	}
+	return 0;
+}
+
+int unlink(const char *path) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_unlinkat, -1);
+	if(int e = mlibc::sys_unlinkat(AT_FDCWD, path, 0); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int unlinkat(int fd, const char *path, int flags) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_unlinkat, -1);
+	if(int e = mlibc::sys_unlinkat(fd, path, flags); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getpagesize() {
+	return mlibc::page_size;
+}
+
+// Code taken from musl
+// GLIBC extension for stdin/stdout
+char *getpass(const char *prompt) {
+	int fdin, fdout;
+	struct termios s, t;
+	ssize_t l;
+	static char password[128];
+
+	if((fdin = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0) {
+		fdin = STDIN_FILENO;
+		fdout = STDOUT_FILENO;
+	} else {
+		fdout = fdin;
+	}
+
+	tcgetattr(fdin, &t);
+	s = t;
+	t.c_lflag &= ~(ECHO | ISIG);
+	t.c_lflag |= ICANON;
+	t.c_iflag &= ~(INLCR | IGNCR);
+	t.c_iflag |= ICRNL;
+	tcsetattr(fdin, TCSAFLUSH, &t);
+	tcdrain(fdin);
+
+	dprintf(fdout, "%s", prompt);
+
+	l = read(fdin, password, sizeof password);
+	if(l >= 0) {
+		if((l > 0 && password[l - 1] == '\n') || l == sizeof password)
+			l--;
+		password[l] = 0;
+	}
+
+	tcsetattr(fdin, TCSAFLUSH, &s);
+
+	dprintf(fdout, "\n");
+	if(fdin != STDIN_FILENO) {
+		close(fdin);
+	}
+
+	return l < 0 ? 0 : password;
+}
+
+char *get_current_dir_name(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+// This is a Linux extension
+pid_t gettid(void) {
+	if(!mlibc::sys_gettid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_gettid()");
+	}
+	return mlibc::sys_gettid();
+}
+
+int getentropy(void *buffer, size_t length) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getentropy, -1);
+	if(length > 256) {
+		errno = EIO;
+		return -1;
+	}
+	if(int e = mlibc::sys_getentropy(buffer, length); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+ssize_t write(int fd, const void *buf, size_t count) {
+	ssize_t bytes_written;
+	if(int e = mlibc::sys_write(fd, buf, count, &bytes_written); e) {
+		errno = e;
+		return (ssize_t)-1;
+	}
+	return bytes_written;
+}
+
+ssize_t read(int fd, void *buf, size_t count) {
+	ssize_t bytes_read;
+	if(int e = mlibc::sys_read(fd, buf, count, &bytes_read); e) {
+		errno = e;
+		return (ssize_t)-1;
+	}
+	return bytes_read;
+}
+
+off_t lseek(int fd, off_t offset, int whence) {
+	off_t new_offset;
+	if(int e = mlibc::sys_seek(fd, offset, whence, &new_offset); e) {
+		errno = e;
+		return (off_t)-1;
+	}
+	return new_offset;
+}
+
+off64_t lseek64(int fd, off64_t offset, int whence) {
+	off64_t new_offset;
+	if(int e = mlibc::sys_seek(fd, offset, whence, &new_offset); e) {
+		errno = e;
+		return (off64_t)-1;
+	}
+	return new_offset;
+}
+
+int close(int fd) {
+	return mlibc::sys_close(fd);
+}
+
+unsigned int sleep(unsigned int secs) {
+	time_t seconds = secs;
+	long nanos = 0;
+	if(!mlibc::sys_sleep) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_sleep()");
+	}
+	mlibc::sys_sleep(&seconds, &nanos);
+	return seconds;
+}
+
+// In contrast to sleep() this functions returns 0/-1 on success/failure.
+int usleep(useconds_t usecs) {
+	time_t seconds = 0;
+	long nanos = usecs * 1000;
+	if(!mlibc::sys_sleep) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_sleep()");
+	}
+	return mlibc::sys_sleep(&seconds, &nanos);
+}
+
+int dup(int fd) {
+	int newfd;
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_dup, -1);
+	if(int e = mlibc::sys_dup(fd, 0, &newfd); e) {
+		errno = e;
+		return -1;
+	}
+	return newfd;
+}
+
+int dup2(int fd, int newfd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_dup2, -1);
+	if(int e = mlibc::sys_dup2(fd, 0, newfd); e) {
+		errno = e;
+		return -1;
+	}
+	return newfd;
+}
+
+pid_t fork(void) {
+	auto self = mlibc::get_current_tcb();
+	pid_t child;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_fork, -1);
+
+	auto hand = self->atforkEnd;
+	while (hand) {
+		if (hand->prepare)
+			hand->prepare();
+
+		hand = hand->prev;
+	}
+
+	if(int e = mlibc::sys_fork(&child); e) {
+		errno = e;
+		return -1;
+	}
+
+	hand = self->atforkBegin;
+	while (hand) {
+		if (!child) {
+			if (hand->child)
+				hand->child();
+		} else {
+			if (hand->parent)
+				hand->parent();
+		}
+		hand = hand->next;
+	}
+
+	return child;
+}
+
+pid_t vfork(void) {
+	pid_t child;
+	/*
+	 * Fork handlers established using pthread_atfork(3) are not
+	 * called when a multithreaded program employing the NPTL
+	 * threading library calls vfork().  Fork handlers are called
+	 * in this case in a program using the LinuxThreads threading
+	 * library.  (See pthreads(7) for a description of Linux
+	 * threading libraries.)
+	 *  - vfork(2), release 5.13 of the Linux man-pages project
+	 *
+	 *  as a result, we call sys_fork instead of running atforks
+	 */
+
+	/* deferring to fork as implementing vfork correctly requires assembly
+	 * to handle not mucking up the stack
+	 */
+	if(!mlibc::sys_fork) {
+		MLIBC_MISSING_SYSDEP();
+		errno = ENOSYS;
+		return -1;
+	}
+
+	if(int e = mlibc::sys_fork(&child); e) {
+		errno = e;
+		return -1;
+	}
+
+	return child;
+}
+
+int execve(const char *path, char *const argv[], char *const envp[]) {
+	char *null_list[] = {
+		nullptr
+	};
+
+	if(!argv)
+		argv = null_list;
+	if(!envp)
+		envp = null_list;
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_execve, -1);
+	int e = mlibc::sys_execve(path, argv, envp);
+	__ensure(e && "sys_execve() is expected to fail if it returns");
+	errno = e;
+	return -1;
+}
+
+gid_t getgid(void) {
+	if(!mlibc::sys_getgid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getgid()");
+	}
+	return mlibc::sys_getgid();
+}
+
+gid_t getegid(void) {
+	if(!mlibc::sys_getegid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getegid()");
+	}
+	return mlibc::sys_getegid();
+}
+
+uid_t getuid(void) {
+	if(!mlibc::sys_getuid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getuid()");
+	}
+	return mlibc::sys_getuid();
+}
+
+uid_t geteuid(void) {
+	if(!mlibc::sys_geteuid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_geteuid()");
+	}
+	return mlibc::sys_geteuid();
+}
+
+pid_t getpid(void) {
+	if(!mlibc::sys_getpid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getpid()");
+	}
+	return mlibc::sys_getpid();
+}
+
+pid_t getppid(void) {
+	if(!mlibc::sys_getppid) {
+		MLIBC_MISSING_SYSDEP();
+		__ensure(!"Cannot continue without sys_getppid()");
+	}
+	return mlibc::sys_getppid();
+}
+
+int access(const char *path, int mode) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_access, -1);
+	if(int e = mlibc::sys_access(path, mode); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+char *getusershell(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void setusershell(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+void endusershell(void) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int isatty(int fd) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_isatty, 0);
+	if(int e = mlibc::sys_isatty(fd); e) {
+		errno = e;
+		return 0;
+	}
+	return 1;
+}
+
+int chroot(const char *ptr) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_chroot, -1);
+	if(int e = mlibc::sys_chroot(ptr); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int daemon(int, int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+char *ctermid(char *s) {
+	return s ? strcpy(s, "/dev/tty") : const_cast<char *>("/dev/tty");
+}
+
+int setresuid(uid_t ruid, uid_t euid, uid_t suid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setresuid, -1);
+	if(int e = mlibc::sys_setresuid(ruid, euid, suid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int setresgid(gid_t rgid, gid_t egid, gid_t sgid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_setresgid, -1);
+	if(int e = mlibc::sys_setresgid(rgid, egid, sgid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getdomainname(char *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int setdomainname(const char *, size_t) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+
+int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getresuid, -1);
+	if(int e = mlibc::sys_getresuid(ruid, euid, suid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_getresgid, -1);
+	if(int e = mlibc::sys_getresgid(rgid, egid, sgid); e) {
+		errno = e;
+		return -1;
+	}
+	return 0;
+}
+
+#if __MLIBC_CRYPT_OPTION
+void encrypt(char[64], int) {
+	__ensure(!"Not implemented");
+	__builtin_unreachable();
+}
+#endif
+
+#if __MLIBC_BSD_OPTION
+void *sbrk(intptr_t increment) {
+	if(increment) {
+		errno = ENOMEM;
+		return (void *)-1;
+	}
+
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_brk, (void *)-1);
+	void *out;
+	if(int e = mlibc::sys_brk(&out); e) {
+		errno = e;
+		return (void *)-1;
+	}
+	return out;
+}
+#endif
diff --git a/lib/mlibc/options/posix/generic/utime-stubs.cpp b/lib/mlibc/options/posix/generic/utime-stubs.cpp
new file mode 100644
index 0000000..f78729f
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/utime-stubs.cpp
@@ -0,0 +1,31 @@
+
+#include <utime.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <bits/ensure.h>
+#include <mlibc/posix-sysdeps.hpp>
+
+int utime(const char *filename, const struct utimbuf *times) {
+	MLIBC_CHECK_OR_ENOSYS(mlibc::sys_utimensat, -1);
+	struct timespec time[2];
+	if(times) {
+		time[0].tv_sec = times->actime;
+		time[0].tv_nsec = 0;
+		time[1].tv_sec = times->modtime;
+		time[1].tv_nsec = 0;
+	} else {
+		time[0].tv_sec = UTIME_NOW;
+		time[0].tv_nsec = UTIME_NOW;
+		time[1].tv_sec = UTIME_NOW;
+		time[1].tv_nsec = UTIME_NOW;
+	}
+
+	if (int e = mlibc::sys_utimensat(AT_FDCWD, filename, time, 0); e) {
+		errno = e;
+		return -1;
+	}
+
+	return 0;
+}
+
diff --git a/lib/mlibc/options/posix/generic/wordexp-stubs.cpp b/lib/mlibc/options/posix/generic/wordexp-stubs.cpp
new file mode 100644
index 0000000..8443527
--- /dev/null
+++ b/lib/mlibc/options/posix/generic/wordexp-stubs.cpp
@@ -0,0 +1,342 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * code taken from OPNSense, with modifications
+ *
+ * Copyright (c) 2002 Tim J. Robbins.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <wordexp.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <stdint.h>
+
+#define SHELL_PATH "/bin/sh"
+#define SHELL_NAME "sh"
+
+static size_t we_read_fully(int fd, char *buffer, size_t len) {
+	size_t done = 0;
+
+	do {
+		ssize_t nread = read(fd, buffer + done, len - done);
+		if(nread == -1 && errno == EINTR)
+			continue;
+		if(nread <= 0)
+			break;
+		done += nread;
+	} while (done != len);
+
+	return done;
+}
+
+static int we_askshell(const char *words, wordexp_t *we, int flags) {
+	int pdes[2]; /* pipe to child */
+	char bbuf[9]; /* buffer for byte count */
+	char wbuf[9]; /* buffer for word count */
+	size_t nwords = 0; /* number of words from child */
+	size_t nbytes = 0; /* number of bytes from child */
+	size_t sofs = 0; /* offset into we->we_strings */
+	size_t vofs = 0; /* offset into we->we_wordv */
+	pid_t pid; /* PID of child */
+	pid_t wpid; /* waitpid return value */
+	int status; /* child exit status */
+	int error; /* our return value */
+	int serrno; /* errno to return */
+	char *np, *p; /* handy pointers */
+	char *nstrings; /* temporary for realloc() */
+	char **new_wordv; /* temporary for realloc() */
+	sigset_t newsigblock;
+	sigset_t oldsigblock;
+	const char *ifs = getenv("IFS");
+
+	serrno = errno;
+
+	if(pipe2(pdes, O_CLOEXEC) < 0)
+		return WRDE_NOSPACE;
+
+	(void)sigemptyset(&newsigblock);
+	(void)sigaddset(&newsigblock, SIGCHLD);
+	(void)sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
+
+	if((pid = fork()) < 0) {
+		serrno = errno;
+		close(pdes[0]);
+		close(pdes[1]);
+		(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
+		errno = serrno;
+		return WRDE_NOSPACE;
+	} else if(pid == 0) {
+		/*
+		 * We are the child; make /bin/sh expand `words'.
+		 */
+		(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
+		if((pdes[1] != STDOUT_FILENO ? dup2(pdes[1], STDOUT_FILENO) : fcntl(pdes[1], F_SETFD, 0)) < 0)
+			_exit(1);
+
+		execl(SHELL_PATH, SHELL_NAME, flags & WRDE_UNDEF ? "-u" : "+u",
+			"-c", "IFS=$1;eval \"$2\";eval \"set -- $3\";IFS=;a=\"$*\";"
+			"printf '%08x' \"$#\" \"${#a}\";printf '%s\\0' \"$@\"", "",
+			ifs != NULL ? ifs : " \t\n",
+			flags & WRDE_SHOWERR ? "" : "exec 2>/dev/null",
+			words,
+			(char *)NULL);
+		_exit(1);
+	}
+
+	/*
+	 * We are the parent; read the output of the shell wordexp function,
+	 * which is a 32-bit hexadecimal word count, a 32-bit hexadecimal
+	 * byte count (not including terminating null bytes), followed by
+	 * the expanded words separated by nulls.
+	 */
+	close(pdes[1]);
+	if(we_read_fully(pdes[0], wbuf, 8) != 8 || we_read_fully(pdes[0], bbuf, 8) != 8) {
+		error = flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX;
+		serrno = errno;
+		goto cleanup;
+	}
+	wbuf[8] = bbuf[8] = '\0';
+	nwords = strtol(wbuf, NULL, 16);
+	nbytes = strtol(bbuf, NULL, 16) + nwords;
+
+	/*
+	 * Allocate or reallocate (when flags & WRDE_APPEND) the word vector
+	 * and string storage buffers for the expanded words we're about to
+	 * read from the child.
+	 */
+	sofs = we->we_nbytes;
+	vofs = we->we_wordc;
+	if((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS | WRDE_APPEND))
+		vofs += we->we_offs;
+	we->we_wordc += nwords;
+	we->we_nbytes += nbytes;
+
+	if((new_wordv = (char **) realloc(we->we_wordv, (we->we_wordc + 1 + (flags & WRDE_DOOFFS ?  we->we_offs : 0)) * sizeof(char *))) == NULL) {
+		error = WRDE_NOSPACE;
+		goto cleanup;
+	}
+
+	we->we_wordv = new_wordv;
+
+	if((nstrings = (char *) realloc(we->we_strings, we->we_nbytes)) == NULL) {
+		error = WRDE_NOSPACE;
+		goto cleanup;
+	}
+
+	for(size_t i = 0; i < vofs; i++) {
+		if(we->we_wordv[i] != NULL)
+			we->we_wordv[i] += nstrings - we->we_strings;
+	}
+	we->we_strings = nstrings;
+
+	if(we_read_fully(pdes[0], we->we_strings + sofs, nbytes) != nbytes) {
+		error = flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX;
+		serrno = errno;
+		goto cleanup;
+	}
+
+	error = 0;
+cleanup:
+	close(pdes[0]);
+
+	do {
+		wpid = waitpid(pid, &status, 0);
+	} while(wpid < 0 && errno == EINTR);
+
+	(void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
+
+	if(error != 0) {
+		errno = serrno;
+		return error;
+	}
+
+	if(wpid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0)
+		return flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX;
+
+	/*
+	 * Break the null-terminated expanded word strings out into
+	 * the vector.
+	 */
+	if(vofs == 0 && flags & WRDE_DOOFFS) {
+		while (vofs < we->we_offs)
+			we->we_wordv[vofs++] = NULL;
+	}
+
+	p = we->we_strings + sofs;
+	while (nwords-- != 0) {
+		we->we_wordv[vofs++] = p;
+		if((np = (char *) memchr(p, '\0', nbytes)) == NULL)
+			return WRDE_NOSPACE;
+
+		nbytes -= np - p + 1;
+		p = np + 1;
+	}
+
+	we->we_wordv[vofs] = NULL;
+	return 0;
+}
+
+/*
+ * we_check --
+ *	Check that the string contains none of the following unquoted
+ *	special characters: <newline> |&;<>(){}
+ *	or command substitutions when WRDE_NOCMD is set in flags.
+ */
+static int we_check(const char *words, int flags)
+{
+	char c;
+	int dquote, level, quote, squote;
+
+	quote = squote = dquote = 0;
+	while ((c = *words++) != '\0') {
+		switch (c) {
+			case '\\': {
+				if(squote == 0)
+					quote ^= 1;
+				continue;
+			}
+			case '\'': {
+				if(quote + dquote == 0)
+					squote ^= 1;
+				break;
+			}
+			case '"': {
+				if(quote + squote == 0)
+					dquote ^= 1;
+				break;
+			}
+			case '`': {
+				if(quote + squote == 0 && flags & WRDE_NOCMD)
+					return WRDE_CMDSUB;
+				while ((c = *words++) != '\0' && c != '`')
+					if(c == '\\' && (c = *words++) == '\0')
+						break;
+				if(c == '\0')
+					return WRDE_SYNTAX;
+				break;
+			}
+			case '|':
+			case '&':
+			case ';':
+			case '<':
+			case '>':
+			case '{':
+			case '}':
+			case '(':
+			case ')':
+			case '\n': {
+				if(quote + squote + dquote == 0)
+					return WRDE_BADCHAR;
+				break;
+			}
+			case '$': {
+				if((c = *words++) == '\0')
+					break;
+				else if(quote + squote == 0 && c == '(') {
+					if(flags & WRDE_NOCMD && *words != '(')
+						return WRDE_CMDSUB;
+					level = 1;
+					while ((c = *words++) != '\0') {
+						if(c == '\\') {
+							if((c = *words++) == '\0')
+								break;
+						} else if(c == '(')
+							level++;
+						else if(c == ')' && --level == 0)
+							break;
+					}
+					if(c == '\0' || level != 0)
+						return WRDE_SYNTAX;
+				} else if(quote + squote == 0 && c == '{') {
+					level = 1;
+					while ((c = *words++) != '\0') {
+						if(c == '\\') {
+							if((c = *words++) == '\0')
+								break;
+						} else if(c == '{')
+							level++;
+						else if(c == '}' && --level == 0)
+							break;
+					}
+					if(c == '\0' || level != 0)
+						return WRDE_SYNTAX;
+				} else
+					--words;
+				break;
+			}
+			default: {
+				break;
+			}
+		}
+		quote = 0;
+	}
+
+	if(quote + squote + dquote != 0)
+		return WRDE_SYNTAX;
+
+	return 0;
+}
+
+int wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags) {
+	int error;
+
+	if(flags & WRDE_REUSE)
+		wordfree(we);
+
+	if((flags & WRDE_APPEND) == 0) {
+		we->we_wordc = 0;
+		we->we_wordv = NULL;
+		we->we_strings = NULL;
+		we->we_nbytes = 0;
+	}
+
+	if((error = we_check(words, flags)) != 0) {
+		wordfree(we);
+		return error;
+	}
+
+	if((error = we_askshell(words, we, flags)) != 0) {
+		wordfree(we);
+		return error;
+	}
+
+	return 0;
+}
+
+void wordfree(wordexp_t *we) {
+	if (we == NULL)
+		return;
+	free(we->we_wordv);
+	free(we->we_strings);
+	we->we_wordv = NULL;
+	we->we_strings = NULL;
+	we->we_nbytes = 0;
+	we->we_wordc = 0;
+}
diff --git a/lib/mlibc/options/posix/include/arpa/inet.h b/lib/mlibc/options/posix/include/arpa/inet.h
new file mode 100644
index 0000000..599987e
--- /dev/null
+++ b/lib/mlibc/options/posix/include/arpa/inet.h
@@ -0,0 +1,46 @@
+#ifndef _ARPA_INET_H
+#define _ARPA_INET_H
+
+#include <netinet/in.h>
+#include <stdint.h>
+#include <sys/socket.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+uint32_t htonl(uint32_t);
+uint16_t htons(uint16_t);
+uint32_t ntohl(uint32_t);
+uint16_t ntohs(uint16_t);
+
+// ----------------------------------------------------------------------------
+// IPv4 address manipulation.
+// ----------------------------------------------------------------------------
+
+in_addr_t inet_addr(const char *);
+char *inet_ntoa(struct in_addr);
+
+// GLIBC replacement for inet_addr().
+int inet_aton(const char *, struct in_addr *);
+
+// ----------------------------------------------------------------------------
+// Generic IP address manipulation.
+// ----------------------------------------------------------------------------
+const char *inet_ntop(int, const void *__restrict, char *__restrict,
+		socklen_t) __attribute__((__nonnull__(3)));
+int inet_pton(int, const char *__restrict, void *__restrict);
+
+struct in_addr inet_makeaddr(in_addr_t net, in_addr_t host);
+in_addr_t inet_netof(struct in_addr in);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _ARPA_INET_H
+
diff --git a/lib/mlibc/options/posix/include/bits/posix/fd_set.h b/lib/mlibc/options/posix/include/bits/posix/fd_set.h
new file mode 100644
index 0000000..554738e
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/fd_set.h
@@ -0,0 +1,14 @@
+#ifndef MLIBC_FD_SET_H
+#define MLIBC_FD_SET_H
+
+#include <bits/types.h>
+
+typedef struct {
+	union {
+		__mlibc_uint8 __mlibc_elems[128];
+		// Some programs require the fds_bits field to be present
+		__mlibc_uint8 fds_bits[128];
+	};
+} fd_set;
+
+#endif // MLIBC_FD_SET_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/id_t.h b/lib/mlibc/options/posix/include/bits/posix/id_t.h
new file mode 100644
index 0000000..f222bc1
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/id_t.h
@@ -0,0 +1,6 @@
+#ifndef _MLIBC_ID_T_H
+#define _MLIBC_ID_T_H
+
+typedef unsigned int id_t;
+
+#endif // _MLIBC_ID_T_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/in_addr_t.h b/lib/mlibc/options/posix/include/bits/posix/in_addr_t.h
new file mode 100644
index 0000000..bac9ff2
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/in_addr_t.h
@@ -0,0 +1,8 @@
+#ifndef MLIBC_IN_ADDR_H
+#define MLIBC_IN_ADDR_H
+
+#include <stdint.h>
+
+typedef uint32_t in_addr_t;
+
+#endif // MLIBC_IN_ADDR_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/in_port_t.h b/lib/mlibc/options/posix/include/bits/posix/in_port_t.h
new file mode 100644
index 0000000..0368159
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/in_port_t.h
@@ -0,0 +1,8 @@
+#ifndef MLIBC_IN_PORT_H
+#define MLIBC_IN_PORT_H
+
+#include <stdint.h>
+
+typedef uint16_t in_port_t;
+
+#endif // MLIBC_IN_PORT_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/iovec.h b/lib/mlibc/options/posix/include/bits/posix/iovec.h
new file mode 100644
index 0000000..c004f1c
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/iovec.h
@@ -0,0 +1,11 @@
+#ifndef MLIBC_IOVEC_H
+#define MLIBC_IOVEC_H
+
+#include <bits/types.h>
+
+struct iovec {
+	void *iov_base;
+	__mlibc_size iov_len;
+};
+
+#endif // MLIBC_IOVEC_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/locale_t.h b/lib/mlibc/options/posix/include/bits/posix/locale_t.h
new file mode 100644
index 0000000..c128d58
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/locale_t.h
@@ -0,0 +1,14 @@
+#ifndef _LOCALE_T_H
+#define _LOCALE_T_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void *locale_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _LOCALE_T_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_ctype.h b/lib/mlibc/options/posix/include/bits/posix/posix_ctype.h
new file mode 100644
index 0000000..2b11057
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_ctype.h
@@ -0,0 +1,36 @@
+#ifndef _POSIX_CTYPE_H
+#define _POSIX_CTYPE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/posix/locale_t.h>
+
+#ifndef __MLIBC_ABI_ONLY
+
+int isalnum_l(int c, locale_t loc);
+int isalpha_l(int c, locale_t loc);
+int isblank_l(int c, locale_t loc);
+int iscntrl_l(int c, locale_t loc);
+int isdigit_l(int c, locale_t loc);
+int isgraph_l(int c, locale_t loc);
+int islower_l(int c, locale_t loc);
+int isprint_l(int c, locale_t loc);
+int ispunct_l(int c, locale_t loc);
+int isspace_l(int c, locale_t loc);
+int isupper_l(int c, locale_t loc);
+int isxdigit_l(int c, locale_t loc);
+
+int isascii_l(int c, locale_t loc);
+
+int tolower_l(int c, locale_t loc);
+int toupper_l(int c, locale_t loc); 
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _POSIX_CTYPE_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_locale.h b/lib/mlibc/options/posix/include/bits/posix/posix_locale.h
new file mode 100644
index 0000000..7554bc5
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_locale.h
@@ -0,0 +1,23 @@
+#ifndef MLIBC_POSIX_LOCALE_H
+#define MLIBC_POSIX_LOCALE_H
+
+#include <bits/posix/locale_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+locale_t newlocale(int category_mask, const char *locale, locale_t base);
+void freelocale(locale_t locobj);
+locale_t uselocale(locale_t locobj);
+locale_t duplocale(locale_t locobj);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIBC_POSIX_LOCALE_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_signal.h b/lib/mlibc/options/posix/include/bits/posix/posix_signal.h
new file mode 100644
index 0000000..20f030f
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_signal.h
@@ -0,0 +1,111 @@
+
+#ifndef MLIBC_POSIX_SIGNAL_H
+#define MLIBC_POSIX_SIGNAL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/ansi/time_t.h>
+#include <bits/ansi/timespec.h>
+#include <bits/posix/pthread_t.h>
+#include <bits/sigset_t.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <mlibc-config.h>
+
+#define FPE_INTDIV      1       /* integer divide by zero */
+#define FPE_INTOVF      2       /* integer overflow */
+#define FPE_FLTDIV      3       /* floating point divide by zero */
+#define FPE_FLTOVF      4       /* floating point overflow */
+#define FPE_FLTUND      5       /* floating point underflow */
+#define FPE_FLTRES      6       /* floating point inexact result */
+#define FPE_FLTINV      7       /* floating point invalid operation */
+#define FPE_FLTSUB      8       /* subscript out of range */
+
+#define TRAP_BRKPT      1       /* process breakpoint */
+#define TRAP_TRACE      2       /* process trace trap */
+
+// Start Glibc stuff
+
+struct _libc_fpxreg {
+  unsigned short int significand[4];
+  unsigned short int exponent;
+  unsigned short int __glibc_reserved1[3];
+};
+
+struct _libc_xmmreg {
+  uint32_t element[4];
+};
+
+struct _libc_fpstate {
+  uint16_t cwd;
+  int16_t  swd;
+  uint16_t ftw;
+  uint16_t fop;
+  uint64_t rip;
+  uint64_t dp;
+  uint32_t mxcsr;
+  uint32_t mxcr_mask;
+  struct _libc_fpxreg _st[8];
+  struct _libc_xmmreg _xmm[16];
+  uint32_t __glibc_reserved1[24];
+};
+
+typedef struct _libc_fpstate *fpregset_t;
+// End Glibc stuff
+
+typedef unsigned long int greg_t;
+
+#define FPE_INTDIV      1       /* integer divide by zero */
+#define FPE_INTOVF      2       /* integer overflow */
+#define FPE_FLTDIV      3       /* floating point divide by zero */
+#define FPE_FLTOVF      4       /* floating point overflow */
+#define FPE_FLTUND      5       /* floating point underflow */
+#define FPE_FLTRES      6       /* floating point inexact result */
+#define FPE_FLTINV      7       /* floating point invalid operation */
+#define FPE_FLTSUB      8       /* subscript out of range */
+
+#define TRAP_BRKPT      1       /* process breakpoint */
+#define TRAP_TRACE      2       /* process trace trap */
+
+#ifndef __MLIBC_ABI_ONLY
+
+// functions to block / wait for signals
+int sigsuspend(const sigset_t *);
+int sigprocmask(int, const sigset_t *__restrict, sigset_t *__restrict);
+
+int pthread_sigmask(int, const sigset_t *__restrict, sigset_t *__restrict);
+int pthread_kill(pthread_t, int);
+
+// functions to handle signals
+int sigaction(int, const struct sigaction *__restrict, struct sigaction *__restrict);
+int sigpending(sigset_t *);
+
+int siginterrupt(int sig, int flag);
+
+int sigaltstack(const stack_t *__restrict ss, stack_t *__restrict oss);
+
+// functions to raise signals
+int kill(pid_t, int);
+int killpg(int, int);
+
+int sigtimedwait(const sigset_t *__restrict set, siginfo_t *__restrict info, const struct timespec *__restrict timeout);
+int sigwait(const sigset_t *__restrict set, int *__restrict sig);
+int sigwaitinfo(const sigset_t *__restrict set, siginfo_t *__restrict info);
+
+// Glibc extension
+#if __MLIBC_GLIBC_OPTION
+int sigisemptyset(const sigset_t *set);
+#endif // __MLIBC_GLIBC_OPTION
+
+int sigqueue(pid_t pid, int sig, const union sigval value);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIBC_POSIX_SIGNAL_H
+
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_stdio.h b/lib/mlibc/options/posix/include/bits/posix/posix_stdio.h
new file mode 100644
index 0000000..4572a04
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_stdio.h
@@ -0,0 +1,72 @@
+
+#ifndef MLIBC_POSIX_STDIO_H
+#define MLIBC_POSIX_STDIO_H
+
+#include <bits/off_t.h>
+#include <bits/size_t.h>
+#include <bits/ssize_t.h>
+
+// MISSING: var_list
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define P_tmpdir "/tmp"
+
+#ifndef __MLIBC_ABI_ONLY
+
+typedef struct __mlibc_file_base FILE;
+
+int fileno(FILE *file);
+FILE *fdopen(int fd, const char *mode);
+
+FILE *fmemopen(void *__restrict, size_t, const char *__restrict);
+int pclose(FILE *);
+FILE *popen(const char*, const char *);
+FILE *open_memstream(char **, size_t *);
+
+int fseeko(FILE *stream, off_t offset, int whence);
+off_t ftello(FILE *stream);
+
+int dprintf(int fd, const char *format, ...);
+int vdprintf(int fd, const char *format, __builtin_va_list args);
+
+char *fgetln(FILE *, size_t *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#define RENAME_EXCHANGE (1 << 1)
+
+// GNU extensions
+typedef ssize_t (cookie_read_function_t)(void *, char *, size_t);
+typedef ssize_t (cookie_write_function_t)(void *, const char *, size_t);
+typedef int (cookie_seek_function_t)(void *, off_t *, int);
+typedef int (cookie_close_function_t)(void *);
+
+typedef struct _IO_cookie_io_functions_t {
+	cookie_read_function_t *read;
+	cookie_write_function_t *write;
+	cookie_seek_function_t *seek;
+	cookie_close_function_t *close;
+} cookie_io_functions_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+#if defined(_GNU_SOURCE)
+
+FILE *fopencookie(void *__restrict cookie, const char *__restrict mode, cookie_io_functions_t io_funcs);
+
+#endif // defined(_GNU_SOURCE)
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+// MISSING: various functions and macros
+
+#endif /* MLIBC_POSIX_STDIO_H */
+
+
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_stdlib.h b/lib/mlibc/options/posix/include/bits/posix/posix_stdlib.h
new file mode 100644
index 0000000..5248fca
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_stdlib.h
@@ -0,0 +1,73 @@
+
+#ifndef MLIBC_POSIX_STDLIB_H
+#define MLIBC_POSIX_STDLIB_H
+
+#include <bits/posix/locale_t.h>
+#include <bits/size_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+long random(void);
+double drand48(void);
+void srand48(long int);
+char *initstate(unsigned int, char *, size_t);
+char *setstate(char *);
+void srandom(unsigned int);
+
+// ----------------------------------------------------------------------------
+// Environment.
+// ----------------------------------------------------------------------------
+
+int putenv(char *);
+int setenv(const char *, const char *, int);
+int unsetenv(const char *);
+
+// ----------------------------------------------------------------------------
+// Path handling.
+// ----------------------------------------------------------------------------
+
+int mkstemp(char *);
+int mkstemps(char *pattern, int suffixlen);
+int mkostemp(char *, int flags);
+int mkostemps(char *pattern, int suffixlen, int flags);
+char *mkdtemp(char *path);
+
+char *realpath(const char *__restrict, char *__restrict);
+
+// ----------------------------------------------------------------------------
+// Pseudoterminals
+// ----------------------------------------------------------------------------
+
+int posix_openpt(int flags);
+int grantpt(int fd);
+int unlockpt(int fd);
+char *ptsname(int fd);
+int ptsname_r(int fd, char *buf, size_t len);
+
+double strtod_l(const char *__restrict__ nptr, char ** __restrict__ endptr, locale_t loc);
+long double strtold_l(const char *__restrict__ nptr, char ** __restrict__ endptr, locale_t loc);
+float strtof_l(const char *__restrict string, char **__restrict end, locale_t loc);
+
+int getloadavg(double *, int);
+
+// GNU extension
+char *secure_getenv(const char *);
+char *canonicalize_file_name(const char *);
+
+// BSD extension
+void *reallocarray(void *, size_t, size_t);
+
+int clearenv(void);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIBC_POSIX_STDLIB_H
+
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_string.h b/lib/mlibc/options/posix/include/bits/posix/posix_string.h
new file mode 100644
index 0000000..1f61942
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_string.h
@@ -0,0 +1,57 @@
+
+#ifndef MLIBC_POSIX_STRING_H
+#define MLIBC_POSIX_STRING_H
+
+#include <alloca.h>
+#include <bits/posix/locale_t.h>
+#include <bits/size_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+char *strdup(const char *string);
+char *strndup(const char *, size_t);
+size_t strnlen(const char *, size_t);
+char *strtok_r(char *__restrict, const char *__restrict, char **__restrict);
+char *strsep(char **stringp, const char *delim);
+char *strsignal(int sig);
+char *stpcpy(char *__restrict, const char *__restrict);
+char *stpncpy(char *__restrict, const char *__restrict, size_t n);
+void *memccpy(void *__restrict dest, const void *__restrict src, int c, size_t n);
+
+int strcoll_l(const char *s1, const char *s2, locale_t locale);
+
+// GNU extensions.
+#if defined(_GNU_SOURCE)
+char *strcasestr(const char *, const char *);
+#define strdupa(x) ({ \
+	const char *str = (x); \
+	size_t len = strlen(str) + 1; \
+	char *buf = alloca(len); \
+	(char *) memcpy(buf, str, len); \
+})
+#define strndupa(x, y) ({ \
+	const char *str = (x); \
+	size_t len = strnlen(str, (y)) + 1; \
+	char *buf = alloca(len); \
+	buf[len - 1] = '\0'; \
+	(char *) memcpy(buf, str, len - 1); \
+})
+void *memrchr(const void *, int, size_t);
+#endif /* defined(_GNU_SOURCE) */
+
+// BSD extensions
+size_t strlcpy(char *d, const char *s, size_t n);
+size_t strlcat(char *d, const char *s, size_t n);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIBC_POSIX_STRING_H
+
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_time.h b/lib/mlibc/options/posix/include/bits/posix/posix_time.h
new file mode 100644
index 0000000..d3e8e1d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_time.h
@@ -0,0 +1,25 @@
+#ifndef MLIBC_POSIX_TIME_H
+#define MLIBC_POSIX_TIME_H
+
+#include <bits/posix/timeval.h>
+
+#define TIMER_ABSTIME 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int utimes(const char *, const struct timeval[2]);
+
+// Not standardized, Linux and BSDs have it
+int futimes(int, const struct timeval[2]);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MLIBC_POSIX_TIME_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/posix_wctype.h b/lib/mlibc/options/posix/include/bits/posix/posix_wctype.h
new file mode 100644
index 0000000..4d2887c
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/posix_wctype.h
@@ -0,0 +1,44 @@
+#ifndef _POSIX_WCTYPE_H
+#define _POSIX_WCTYPE_H
+
+#include <bits/posix/locale_t.h>
+#include <bits/wint_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+typedef unsigned long wctype_t;
+typedef unsigned long wctrans_t;
+
+int iswalnum_l(wint_t, locale_t);
+int iswblank_l(wint_t, locale_t);
+int iswcntrl_l(wint_t, locale_t);
+int iswdigit_l(wint_t, locale_t);
+int iswgraph_l(wint_t, locale_t);
+int iswlower_l(wint_t, locale_t);
+int iswprint_l(wint_t, locale_t);
+int iswpunct_l(wint_t, locale_t);
+int iswspace_l(wint_t, locale_t);
+int iswupper_l(wint_t, locale_t);
+int iswxdigit_l(wint_t, locale_t);
+int iswalpha_l(wint_t, locale_t);
+
+wctype_t wctype_l(const char *);
+int iswctype_l(wint_t, wctype_t);
+
+wint_t towlower_l(wint_t, locale_t);
+wint_t towupper_l(wint_t, locale_t);
+
+wctrans_t wctrans_l(const char *, locale_t);
+wint_t towctrans_l(wint_t, wctrans_t, locale_t);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _POSIX_WCTYPE_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/pthread_t.h b/lib/mlibc/options/posix/include/bits/posix/pthread_t.h
new file mode 100644
index 0000000..1310c40
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/pthread_t.h
@@ -0,0 +1,8 @@
+#ifndef _MLIBC_BITS_PTHREAD_T_HPP
+#define _MLIBC_BITS_PTHREAD_T_HPP
+
+#include <bits/threads.h>
+
+typedef struct __mlibc_thread_data *pthread_t;
+
+#endif // _MLIBC_BITS_PTHREAD_T_HPP
diff --git a/lib/mlibc/options/posix/include/bits/posix/stat.h b/lib/mlibc/options/posix/include/bits/posix/stat.h
new file mode 100644
index 0000000..4dd081d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/stat.h
@@ -0,0 +1,24 @@
+#ifndef MLIBC_STAT_H
+#define MLIBC_STAT_H
+
+#include <abi-bits/stat.h>
+
+// Used by utimensat and friends
+#define UTIME_NOW ((1l << 30) - 1l)
+#define UTIME_OMIT ((1l << 30) - 2l)
+
+#define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
+#define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
+#define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
+#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
+#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
+#define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
+
+// POSIX compatibility macros
+#define st_atime st_atim.tv_sec
+#define st_mtime st_mtim.tv_sec
+#define st_ctime st_ctim.tv_sec
+
+#endif // MLIBC_STAT_H
+
diff --git a/lib/mlibc/options/posix/include/bits/posix/timer_t.h b/lib/mlibc/options/posix/include/bits/posix/timer_t.h
new file mode 100644
index 0000000..b230501
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/timer_t.h
@@ -0,0 +1,6 @@
+#ifndef _MLIBC_TIMER_T_H
+#define _MLIBC_TIMER_T_H
+
+typedef void * timer_t;
+
+#endif // _MLIBC_TIMER_T_H
diff --git a/lib/mlibc/options/posix/include/bits/posix/timeval.h b/lib/mlibc/options/posix/include/bits/posix/timeval.h
new file mode 100644
index 0000000..445ee7f
--- /dev/null
+++ b/lib/mlibc/options/posix/include/bits/posix/timeval.h
@@ -0,0 +1,12 @@
+#ifndef MLIBC_TIMEVAL_H
+#define MLIBC_TIMEVAL_H
+
+#include <bits/ansi/time_t.h>
+#include <abi-bits/suseconds_t.h>
+
+struct timeval {
+	time_t tv_sec;
+	suseconds_t tv_usec;
+};
+
+#endif // MLIBC_TIMEVAL_H
diff --git a/lib/mlibc/options/posix/include/byteswap.h b/lib/mlibc/options/posix/include/byteswap.h
new file mode 100644
index 0000000..74b9fe2
--- /dev/null
+++ b/lib/mlibc/options/posix/include/byteswap.h
@@ -0,0 +1,23 @@
+
+#ifndef _BYTESWAP_H
+#define _BYTESWAP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define bswap_16(x) __builtin_bswap16(x)
+#define bswap_32(x) __builtin_bswap32(x)
+#define bswap_64(x) __builtin_bswap64(x)
+
+// Some programs like eudev call these functions instead
+#define __bswap_16(x) __builtin_bswap16(x)
+#define __bswap_32(x) __builtin_bswap32(x)
+#define __bswap_64(x) __builtin_bswap64(x)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _BYTESWAP_H
+
diff --git a/lib/mlibc/options/posix/include/dirent.h b/lib/mlibc/options/posix/include/dirent.h
new file mode 100644
index 0000000..b50566d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/dirent.h
@@ -0,0 +1,76 @@
+
+#ifndef _DIRENT_H
+#define _DIRENT_H
+
+#include <abi-bits/ino_t.h>
+#include <bits/off_t.h>
+#include <bits/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define DT_UNKNOWN 0
+#define DT_FIFO 1
+#define DT_CHR 2
+#define DT_DIR 4
+#define DT_BLK 6
+#define DT_REG 8
+#define DT_LNK 10
+#define DT_SOCK 12
+#define DT_WHT 14
+
+#define __MLIBC_DIRENT_BODY ino_t d_ino; \
+			off_t d_off; \
+			unsigned short d_reclen; \
+			unsigned char d_type; \
+			char d_name[1024];
+
+struct dirent {
+	__MLIBC_DIRENT_BODY
+};
+
+struct dirent64 {
+	__MLIBC_DIRENT_BODY
+};
+
+#define d_fileno d_ino
+
+#undef __MLIBC_DIRENT_BODY
+
+#define IFTODT(mode) (((mode) & 0170000) >> 12)
+
+struct __mlibc_dir_struct {
+	int __handle;
+	__mlibc_size __ent_next;
+	__mlibc_size __ent_limit;
+	char __ent_buffer[2048];
+	struct dirent __current;
+};
+
+typedef struct __mlibc_dir_struct DIR;
+
+#ifndef __MLIBC_ABI_ONLY
+
+int alphasort(const struct dirent **, const struct dirent **);
+int closedir(DIR *);
+int dirfd(DIR *);
+DIR *fdopendir(int);
+DIR *opendir(const char *);
+struct dirent *readdir(DIR *);
+int readdir_r(DIR *__restrict, struct dirent *__restrict, struct dirent **__restrict);
+void rewinddir(DIR *);
+int scandir(const char *, struct dirent ***, int (*)(const struct dirent *),
+		int (*)(const struct dirent **, const struct dirent **));
+void seekdir(DIR *, long);
+long telldir(DIR *);
+int versionsort(const struct dirent **, const struct dirent **);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _DIRENT_H
+
diff --git a/lib/mlibc/options/posix/include/dlfcn.h b/lib/mlibc/options/posix/include/dlfcn.h
new file mode 100644
index 0000000..3bb8a02
--- /dev/null
+++ b/lib/mlibc/options/posix/include/dlfcn.h
@@ -0,0 +1,52 @@
+
+#ifndef _DLFCN_H
+#define _DLFCN_H
+
+#define RTLD_LOCAL 0
+#define RTLD_NOW 1
+#define RTLD_GLOBAL 2
+#define RTLD_NOLOAD 4
+#define RTLD_NODELETE 8
+#define RTLD_DEEPBIND 16
+#define RTLD_LAZY 32
+
+#define RTLD_NEXT ((void *)-1)
+#define RTLD_DEFAULT ((void *)0)
+
+#define RTLD_DI_LINKMAP 2
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int dlclose(void *);
+char *dlerror(void);
+void *dlopen(const char *, int);
+void *dlsym(void *__restrict, const char *__restrict);
+void *dlvsym(void *__restrict, const char *__restrict, const char *__restrict);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+//gnu extension
+typedef struct {
+	const char *dli_fname;
+	void *dli_fbase;
+	const char *dli_sname;
+	void *dli_saddr;
+} Dl_info;
+
+#ifndef __MLIBC_ABI_ONLY
+
+int dladdr(const void *, Dl_info *);
+int dlinfo(void *, int, void *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _DLFCN_H
+
diff --git a/lib/mlibc/options/posix/include/fcntl.h b/lib/mlibc/options/posix/include/fcntl.h
new file mode 100644
index 0000000..9983219
--- /dev/null
+++ b/lib/mlibc/options/posix/include/fcntl.h
@@ -0,0 +1,76 @@
+
+#ifndef _FCNTL_H
+#define _FCNTL_H
+
+#include <abi-bits/fcntl.h>
+#include <abi-bits/seek-whence.h>
+#include <abi-bits/mode_t.h>
+#include <abi-bits/pid_t.h>
+#include <bits/posix/iovec.h>
+#include <bits/off_t.h>
+#include <bits/ssize_t.h>
+#include <bits/size_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define O_NDELAY O_NONBLOCK
+
+struct flock {
+	short l_type;
+	short l_whence;
+	off_t l_start;
+	off_t l_len;
+	pid_t l_pid;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int creat(const char *, mode_t);
+int fallocate(int fd, int mode, off_t offset, off_t len);
+int fcntl(int fd, int command, ...);
+int open(const char *path, int flags, ...);
+int openat(int, const char *, int, ...);
+int posix_fadvise(int, off_t, off_t, int);
+int posix_fallocate(int, off_t, off_t);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+// This is a linux extension
+
+struct file_handle {
+        unsigned int handle_bytes;
+        int handle_type;
+        unsigned char f_handle[0];
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int name_to_handle_at(int, const char *, struct file_handle *, int *, int);
+int open_by_handle_at(int, struct file_handle *, int);
+
+ssize_t splice(int fd_in, off_t *off_in, int fd_out, off_t *off_out, size_t len, unsigned int flags);
+ssize_t vmsplice(int fd, const struct iovec *iov, size_t nr_segs, unsigned int flags);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#define SPLICE_F_MOVE 1
+#define SPLICE_F_NONBLOCK 2
+#define SPLICE_F_MORE 4
+#define SPLICE_F_GIFT 8
+
+#define AT_NO_AUTOMOUNT 0x800
+
+#define F_SETPIPE_SZ 1031
+#define F_GETPIPE_SZ 1032
+
+#define FALLOC_FL_KEEP_SIZE 1
+#define FALLOC_FL_PUNCH_HOLE 2
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _FCNTL_H
+
diff --git a/lib/mlibc/options/posix/include/fnmatch.h b/lib/mlibc/options/posix/include/fnmatch.h
new file mode 100644
index 0000000..3eccbd0
--- /dev/null
+++ b/lib/mlibc/options/posix/include/fnmatch.h
@@ -0,0 +1,33 @@
+
+#ifndef _FNMATCH_H
+#define _FNMATCH_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// POSIX-defined fnmatch() flags.
+#define FNM_PATHNAME 0x1
+#define FNM_NOESCAPE 0x2
+#define FNM_PERIOD 0x4
+
+// GNU extensions for fnmatch() flags.
+#define FNM_LEADING_DIR 0x8
+#define FNM_CASEFOLD 0x10
+#define FNM_EXTMATCH 0x20
+
+// fnmatch() return values.
+#define FNM_NOMATCH 1
+
+#ifndef __MLIBC_ABI_ONLY
+
+int fnmatch(const char *, const char *, int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _FNMATCH_H
+
diff --git a/lib/mlibc/options/posix/include/ftw.h b/lib/mlibc/options/posix/include/ftw.h
new file mode 100644
index 0000000..bde283d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/ftw.h
@@ -0,0 +1,43 @@
+
+#ifndef _FTW_H
+#define _FTW_H
+
+#include <bits/posix/stat.h>
+
+#define FTW_F 1
+#define FTW_D 2
+#define FTW_DNR 3
+#define FTW_DP 4
+#define FTW_NS 5
+#define FTW_SL 6
+#define FTW_SLN 7
+
+#define FTW_PHYS 1
+#define FTW_MOUNT 2
+#define FTW_DEPTH 4
+#define FTW_CHDIR 8
+
+#define FTW_CONTINUE 0
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct FTW {
+	int base;
+	int level;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int ftw(const char *, int (*)(const char *, const struct stat *, int), int);
+int nftw(const char *, int (*)(const char *, const struct stat *, int, struct FTW *), int, int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _FTW_H
+
diff --git a/lib/mlibc/options/posix/include/glob.h b/lib/mlibc/options/posix/include/glob.h
new file mode 100644
index 0000000..2bf9e48
--- /dev/null
+++ b/lib/mlibc/options/posix/include/glob.h
@@ -0,0 +1,58 @@
+
+#ifndef _GLOB_H
+#define _GLOB_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/size_t.h>
+
+#define GLOB_APPEND 0x01
+#define GLOB_DOOFFS 0x02
+#define GLOB_ERR 0x04
+#define GLOB_MARK 0x08
+#define GLOB_NOCHECK 0x10
+#define GLOB_NOESCAPE 0x20
+#define GLOB_NOSORT 0x40
+#define GLOB_PERIOD 0x80
+#define GLOB_TILDE 0x100
+#define GLOB_TILDE_CHECK 0x200
+#define GLOB_BRACE 0x400
+#define GLOB_NOMAGIC 0x800
+#define GLOB_ALTDIRFUNC 0x1000
+#define GLOB_ONLYDIR 0x2000
+#define GLOB_MAGCHAR 0x4000
+
+#define GLOB_ABORTED 1
+#define GLOB_NOMATCH 2
+#define GLOB_NOSPACE 3
+#define GLOB_NOSYS 4
+
+struct stat;
+typedef struct glob_t {
+	size_t gl_pathc;
+	char **gl_pathv;
+	size_t gl_offs;
+	int gl_flags;
+	void (*gl_closedir) (void *);
+	struct dirent *(*gl_readdir) (void *);
+	void *(*gl_opendir) (const char *);
+	int (*gl_lstat) (const char *__restrict, struct stat *__restrict);
+	int (*gl_stat) (const char *__restrict, struct stat *__restrict);
+} glob_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+int glob(const char *__restirct, int, int(*)(const char *, int), struct glob_t *__restrict);
+void globfree(struct glob_t *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _GLOB_H
+
+
diff --git a/lib/mlibc/options/posix/include/grp.h b/lib/mlibc/options/posix/include/grp.h
new file mode 100644
index 0000000..a50396e
--- /dev/null
+++ b/lib/mlibc/options/posix/include/grp.h
@@ -0,0 +1,43 @@
+#ifndef _GRP_H
+#define _GRP_H
+
+#include <stddef.h>
+#include <stdio.h>
+#include <abi-bits/gid_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct group {
+	char *gr_name;
+	char *gr_passwd;
+	gid_t gr_gid;
+	char **gr_mem;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+void endgrent(void);
+struct group *getgrent(void);
+struct group *getgrgid(gid_t);
+int getgrgid_r(gid_t, struct group *, char *, size_t, struct group **);
+struct group *getgrnam(const char *);
+int getgrnam_r(const char *, struct group *, char *, size_t, struct group **);
+void setgrent(void);
+int putgrent(const struct group *, FILE *);
+struct group *fgetgrent(FILE *);
+
+int setgroups(size_t size, const gid_t *list);
+int initgroups(const char *user, gid_t group);
+
+// Non standard extension
+int getgrouplist(const char *, gid_t, gid_t *, int *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _GRP_H
diff --git a/lib/mlibc/options/posix/include/langinfo.h b/lib/mlibc/options/posix/include/langinfo.h
new file mode 100644
index 0000000..5436a54
--- /dev/null
+++ b/lib/mlibc/options/posix/include/langinfo.h
@@ -0,0 +1,24 @@
+
+#ifndef _LANGINFO_H
+#define _LANGINFO_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/posix/locale_t.h>
+#include <bits/nl_item.h>
+
+#ifndef __MLIBC_ABI_ONLY
+
+char *nl_langinfo(nl_item);
+char *nl_langinfo_l(nl_item, locale_t);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _LANGINFO_H
+
diff --git a/lib/mlibc/options/posix/include/libgen.h b/lib/mlibc/options/posix/include/libgen.h
new file mode 100644
index 0000000..fa53fc5
--- /dev/null
+++ b/lib/mlibc/options/posix/include/libgen.h
@@ -0,0 +1,28 @@
+
+#ifndef _LIBGEN_H
+#define _LIBGEN_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(basename) && defined(_GNU_SOURCE)
+/* see: ./options/ansi/include/string.h, search for __mlibc_gnu_basename */
+# undef basename
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+char *basename(char *);
+#define basename basename
+char *dirname(char *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _LIBGEN_H
+
+
diff --git a/lib/mlibc/options/posix/include/mlibc/lookup.hpp b/lib/mlibc/options/posix/include/mlibc/lookup.hpp
new file mode 100644
index 0000000..71f84e7
--- /dev/null
+++ b/lib/mlibc/options/posix/include/mlibc/lookup.hpp
@@ -0,0 +1,58 @@
+#ifndef _MLIBC_LOOKUP
+#define _MLIBC_LOOKUP
+
+#include <stdint.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <frg/string.hpp>
+#include <frg/vector.hpp>
+#include <frg/span.hpp>
+#include <frg/array.hpp>
+#include <mlibc/allocator.hpp>
+
+namespace mlibc {
+
+struct dns_addr_buf {
+	dns_addr_buf()
+	: name(getAllocator()) {}
+	frg::string<MemoryAllocator> name;
+	int family;
+	uint8_t addr[16];
+};
+
+struct lookup_result {
+	lookup_result()
+	: buf(getAllocator()), aliases(getAllocator()) {}
+	frg::vector<struct dns_addr_buf, MemoryAllocator> buf;
+	frg::vector<frg::string<MemoryAllocator>, MemoryAllocator> aliases;
+};
+
+struct dns_header {
+	uint16_t identification;
+	uint16_t flags;
+	uint16_t no_q;
+	uint16_t no_ans;
+	uint16_t no_auths;
+	uint16_t no_additional;
+};
+
+struct ai_buf {
+	struct addrinfo ai;
+	union sa {
+		struct sockaddr_in sin;
+		struct sockaddr_in6 sin6;
+	} sa;
+};
+
+int lookup_name_dns(struct lookup_result &buf, const char *name,
+		frg::string<MemoryAllocator> &canon_name);
+int lookup_addr_dns(frg::span<char> name, frg::array<uint8_t, 16> &addr, int family);
+int lookup_name_hosts(struct lookup_result &buf, const char *name,
+		frg::string<MemoryAllocator> &canon_name);
+int lookup_addr_hosts(frg::span<char> name, frg::array<uint8_t, 16> &addr, int family);
+int lookup_name_null(struct lookup_result &buf, int flags, int family);
+int lookup_name_ip(struct lookup_result &buf, const char *name, int family);
+
+} // namespace mlibc
+
+#endif // _MLIBC_LOOKUP
diff --git a/lib/mlibc/options/posix/include/mlibc/posix-file-io.hpp b/lib/mlibc/options/posix/include/mlibc/posix-file-io.hpp
new file mode 100644
index 0000000..ac316ac
--- /dev/null
+++ b/lib/mlibc/options/posix/include/mlibc/posix-file-io.hpp
@@ -0,0 +1,102 @@
+#ifndef MLIBC_POSIX_FILE_IO_HPP
+#define MLIBC_POSIX_FILE_IO_HPP
+
+#include <frg/span.hpp>
+#include <frg/vector.hpp>
+#include <mlibc/file-io.hpp>
+#include <mlibc/allocator.hpp>
+
+namespace mlibc {
+
+struct mem_file : abstract_file {
+	mem_file(int flags, void (*do_dispose)(abstract_file *) = nullptr) : abstract_file{do_dispose}, _flags{flags} { };
+
+	int reopen(const char *path, const char *mode) override;
+protected:
+	int determine_type(stream_type *type) override;
+	int determine_bufmode(buffer_mode *mode) override;
+
+	virtual frg::span<char> _buffer() = 0;
+	virtual size_t _buffer_size() const = 0;
+
+	off_t _pos = 0;
+	int _flags = 0;
+	// maintains the size of buffer contents as required by POSIX
+	off_t _max_size = 0;
+};
+
+struct memstream_mem_file final : public mem_file {
+	memstream_mem_file(char **ptr, size_t *sizeloc, int flags, void (*do_dispose)(abstract_file *) = nullptr);
+
+	int close() override;
+
+	int io_read(char *buffer, size_t max_size, size_t *actual_size) override;
+	int io_write(const char *buffer, size_t max_size, size_t *actual_size) override;
+	int io_seek(off_t offset, int whence, off_t *new_offset) override;
+
+	frg::span<char> _buffer() override {
+		return {_buf.data(), _buffer_size()};
+	}
+
+	size_t _buffer_size() const override {
+		return _buf.size();
+	}
+
+private:
+	void _update_ptrs();
+
+	// Where to write back buffer and size on flush and close.
+	char **_bufloc;
+	size_t *_sizeloc;
+
+	frg::vector<char, MemoryAllocator> _buf = {getAllocator()};
+};
+
+struct fmemopen_mem_file final : public mem_file {
+	fmemopen_mem_file(void *in_buf, size_t size, int flags, void (*do_dispose)(abstract_file *) = nullptr);
+
+	int close() override;
+
+	int io_read(char *buffer, size_t max_size, size_t *actual_size) override;
+	int io_write(const char *buffer, size_t max_size, size_t *actual_size) override;
+	int io_seek(off_t offset, int whence, off_t *new_offset) override;
+
+	frg::span<char> _buffer() override {
+		return {reinterpret_cast<char *>(_inBuffer), _buffer_size()};
+	}
+
+	size_t _buffer_size() const override {
+		return _inBufferSize;
+	}
+
+private:
+	void *_inBuffer;
+	size_t _inBufferSize;
+
+	bool _needsDeallocation = false;
+};
+
+struct cookie_file : abstract_file {
+	cookie_file(void *cookie, int flags, cookie_io_functions_t funcs, void (*do_dispose)(abstract_file *) = nullptr)
+		: abstract_file{do_dispose}, _cookie{cookie}, _flags{flags}, _funcs{funcs} { }
+
+	int close() override;
+	int reopen(const char *path, const char *mode) override;
+protected:
+	int determine_type(stream_type *type) override;
+	int determine_bufmode(buffer_mode *mode) override;
+
+	int io_read(char *buffer, size_t max_size, size_t *actual_size) override;
+	int io_write(const char *buffer, size_t max_size, size_t *actual_size) override;
+	int io_seek(off_t offset, int whence, off_t *new_offset) override;
+
+private:
+	void *_cookie;
+
+	int _flags;
+	cookie_io_functions_t _funcs;
+};
+
+} // namespace mlibc
+
+#endif // MLIBC_POSIX_FILE_IO_HPP
diff --git a/lib/mlibc/options/posix/include/mlibc/posix-sysdeps.hpp b/lib/mlibc/options/posix/include/mlibc/posix-sysdeps.hpp
new file mode 100644
index 0000000..ba77b32
--- /dev/null
+++ b/lib/mlibc/options/posix/include/mlibc/posix-sysdeps.hpp
@@ -0,0 +1,240 @@
+#ifndef MLIBC_POSIX_SYSDEPS
+#define MLIBC_POSIX_SYSDEPS
+
+#include <stddef.h>
+
+#include <abi-bits/seek-whence.h>
+#include <abi-bits/vm-flags.h>
+#include <bits/off_t.h>
+#include <bits/ssize_t.h>
+#include <mlibc/fsfd_target.hpp>
+
+#include <fcntl.h>
+#include <time.h>
+#include <abi-bits/pid_t.h>
+#include <abi-bits/socklen_t.h>
+#include <bits/posix/stat.h>
+#include <poll.h>
+#include <stdarg.h>
+#include <sys/socket.h>
+#include <sys/resource.h>
+#include <sys/utsname.h>
+#include <sys/select.h>
+#include <sys/sem.h>
+#include <sys/statvfs.h>
+#include <sys/time.h>
+#include <sys/times.h>
+#include <sys/wait.h>
+#include <sched.h>
+#include <termios.h>
+#include <time.h>
+#include <ucontext.h>
+
+namespace [[gnu::visibility("hidden")]] mlibc {
+
+void sys_libc_log(const char *message);
+[[noreturn]] void sys_libc_panic();
+
+[[noreturn]] void sys_exit(int status);
+[[noreturn, gnu::weak]] void sys_thread_exit();
+int sys_clock_get(int clock, time_t *secs, long *nanos);
+
+int sys_open(const char *pathname, int flags, mode_t mode, int *fd);
+[[gnu::weak]] int sys_flock(int fd, int options);
+
+[[gnu::weak]] int sys_open_dir(const char *path, int *handle);
+[[gnu::weak]] int sys_read_entries(int handle, void *buffer, size_t max_size,
+		size_t *bytes_read);
+
+int sys_read(int fd, void *buf, size_t count, ssize_t *bytes_read);
+[[gnu::weak]] int sys_readv(int fd, const struct iovec *iovs, int iovc, ssize_t *bytes_read);
+
+int sys_write(int fd, const void *buf, size_t count, ssize_t *bytes_written);
+[[gnu::weak]] int sys_pread(int fd, void *buf, size_t n, off_t off, ssize_t *bytes_read);
+[[gnu::weak]] int sys_pwrite(int fd, const void *buf, size_t n, off_t off, ssize_t *bytes_read);
+
+int sys_seek(int fd, off_t offset, int whence, off_t *new_offset);
+int sys_close(int fd);
+
+[[gnu::weak]] int sys_access(const char *path, int mode);
+[[gnu::weak]] int sys_faccessat(int dirfd, const char *pathname, int mode, int flags);
+[[gnu::weak]] int sys_dup(int fd, int flags, int *newfd);
+[[gnu::weak]] int sys_dup2(int fd, int flags, int newfd);
+// In contrast to the isatty() library function, the sysdep function uses return value
+// zero (and not one) to indicate that the file is a terminal.
+[[gnu::weak]] int sys_isatty(int fd);
+[[gnu::weak]] int sys_stat(fsfd_target fsfdt, int fd, const char *path, int flags,
+		struct stat *statbuf);
+[[gnu::weak]] int sys_statvfs(const char *path, struct statvfs *out);
+[[gnu::weak]] int sys_fstatvfs(int fd, struct statvfs *out);
+[[gnu::weak]] int sys_readlink(const char *path, void *buffer, size_t max_size, ssize_t *length);
+[[gnu::weak]] int sys_rmdir(const char *path);
+[[gnu::weak]] int sys_ftruncate(int fd, size_t size);
+[[gnu::weak]] int sys_fallocate(int fd, off_t offset, size_t size);
+[[gnu::weak]] int sys_unlinkat(int fd, const char *path, int flags);
+[[gnu::weak]] int sys_openat(int dirfd, const char *path, int flags, mode_t mode, int *fd);
+[[gnu::weak]] int sys_socket(int family, int type, int protocol, int *fd);
+[[gnu::weak]] int sys_msg_send(int fd, const struct msghdr *hdr, int flags, ssize_t *length);
+[[gnu::weak]] ssize_t sys_sendto(int fd, const void *buffer, size_t size, int flags, const struct sockaddr *sock_addr, socklen_t addr_length, ssize_t *length);
+[[gnu::weak]] int sys_msg_recv(int fd, struct msghdr *hdr, int flags, ssize_t *length);
+[[gnu::weak]] ssize_t sys_recvfrom(int fd, void *buffer, size_t size, int flags, struct sockaddr *sock_addr, socklen_t *addr_length, ssize_t *length);
+[[gnu::weak]] int sys_listen(int fd, int backlog);
+[[gnu::weak]] gid_t sys_getgid();
+[[gnu::weak]] gid_t sys_getegid();
+[[gnu::weak]] uid_t sys_getuid();
+[[gnu::weak]] uid_t sys_geteuid();
+[[gnu::weak]] pid_t sys_getpid();
+[[gnu::weak]] pid_t sys_gettid();
+[[gnu::weak]] pid_t sys_getppid();
+[[gnu::weak]] int sys_getpgid(pid_t pid, pid_t *pgid);
+[[gnu::weak]] int sys_getsid(pid_t pid, pid_t *sid);
+[[gnu::weak]] int sys_setpgid(pid_t pid, pid_t pgid);
+[[gnu::weak]] int sys_setuid(uid_t uid);
+[[gnu::weak]] int sys_seteuid(uid_t euid);
+[[gnu::weak]] int sys_setgid(gid_t gid);
+[[gnu::weak]] int sys_setegid(gid_t egid);
+[[gnu::weak]] int sys_getgroups(size_t size, const gid_t *list, int *ret);
+[[gnu::weak]] void sys_yield();
+[[gnu::weak]] int sys_sleep(time_t *secs, long *nanos);
+[[gnu::weak]] int sys_fork(pid_t *child);
+[[gnu::weak]] int sys_execve(const char *path, char *const argv[], char *const envp[]);
+[[gnu::weak]] int sys_pselect(int num_fds, fd_set *read_set, fd_set *write_set,
+		fd_set *except_set, const struct timespec *timeout, const sigset_t *sigmask, int *num_events);
+[[gnu::weak]] int sys_getrusage(int scope, struct rusage *usage);
+[[gnu::weak]] int sys_getrlimit(int resource, struct rlimit *limit);
+[[gnu::weak]] int sys_setrlimit(int resource, const struct rlimit *limit);
+[[gnu::weak]] int sys_getpriority(int which, id_t who, int *value);
+[[gnu::weak]] int sys_setpriority(int which, id_t who, int prio);
+[[gnu::weak]] int sys_getschedparam(void *tcb, int *policy, struct sched_param *param);
+[[gnu::weak]] int sys_setschedparam(void *tcb, int policy, const struct sched_param *param);
+[[gnu::weak]] int sys_get_max_priority(int policy, int *out);
+[[gnu::weak]] int sys_get_min_priority(int policy, int *out);
+[[gnu::weak]] int sys_getcwd(char *buffer, size_t size);
+[[gnu::weak]] int sys_chdir(const char *path);
+[[gnu::weak]] int sys_fchdir(int fd);
+[[gnu::weak]] int sys_chroot(const char *path);
+[[gnu::weak]] int sys_mkdir(const char *path, mode_t mode);
+[[gnu::weak]] int sys_mkdirat(int dirfd, const char *path, mode_t mode);
+[[gnu::weak]] int sys_link(const char *old_path, const char *new_path);
+[[gnu::weak]] int sys_linkat(int olddirfd, const char *old_path, int newdirfd, const char *new_path, int flags);
+[[gnu::weak]] int sys_symlink(const char *target_path, const char *link_path);
+[[gnu::weak]] int sys_symlinkat(const char *target_path, int dirfd, const char *link_path);
+[[gnu::weak]] int sys_rename(const char *path, const char *new_path);
+[[gnu::weak]] int sys_renameat(int olddirfd, const char *old_path, int newdirfd, const char *new_path);
+[[gnu::weak]] int sys_fcntl(int fd, int request, va_list args, int *result);
+[[gnu::weak]] int sys_ttyname(int fd, char *buf, size_t size);
+[[gnu::weak]] int sys_fadvise(int fd, off_t offset, off_t length, int advice);
+[[gnu::weak]] void sys_sync();
+[[gnu::weak]] int sys_fsync(int fd);
+[[gnu::weak]] int sys_fdatasync(int fd);
+[[gnu::weak]] int sys_chmod(const char *pathname, mode_t mode);
+[[gnu::weak]] int sys_fchmod(int fd, mode_t mode);
+[[gnu::weak]] int sys_fchmodat(int fd, const char *pathname, mode_t mode, int flags);
+[[gnu::weak]] int sys_utimensat(int dirfd, const char *pathname, const struct timespec times[2], int flags);
+[[gnu::weak]] int sys_mlock(const void *addr, size_t length);
+[[gnu::weak]] int sys_munlock(const void *addr, size_t length);
+[[gnu::weak]] int sys_mlockall(int flags);
+[[gnu::weak]] int sys_mlock(const void *addr, size_t len);
+[[gnu::weak]] int sys_munlockall(void);
+[[gnu::weak]] int sys_mincore(void *addr, size_t length, unsigned char *vec);
+
+// mlibc assumes that anonymous memory returned by sys_vm_map() is zeroed by the kernel / whatever is behind the sysdeps
+int sys_vm_map(void *hint, size_t size, int prot, int flags, int fd, off_t offset, void **window);
+
+[[gnu::weak]] int sys_vm_remap(void *pointer, size_t size, size_t new_size, void **window);
+[[gnu::weak]] int sys_vm_protect(void *pointer, size_t size, int prot);
+
+int sys_vm_unmap(void *pointer, size_t size);
+
+[[gnu::weak]] int sys_setsid(pid_t *sid);
+[[gnu::weak]] int sys_tcgetattr(int fd, struct termios *attr);
+[[gnu::weak]] int sys_tcsetattr(int, int, const struct termios *attr);
+[[gnu::weak]] int sys_tcflow(int, int);
+[[gnu::weak]] int sys_tcflush(int fd, int queue);
+[[gnu::weak]] int sys_tcdrain(int);
+[[gnu::weak]] int sys_pipe(int *fds, int flags);
+[[gnu::weak]] int sys_socketpair(int domain, int type_and_flags, int proto, int *fds);
+[[gnu::weak]] int sys_poll(struct pollfd *fds, nfds_t count, int timeout, int *num_events);
+[[gnu::weak]] int sys_ioctl(int fd, unsigned long request, void *arg, int *result);
+[[gnu::weak]] int sys_getsockopt(int fd, int layer, int number,
+		void *__restrict buffer, socklen_t *__restrict size);
+[[gnu::weak]] int sys_setsockopt(int fd, int layer, int number,
+		const void *buffer, socklen_t size);
+[[gnu::weak]] int sys_shutdown(int sockfd, int how);
+[[gnu::weak]] int sys_sigprocmask(int how, const sigset_t *__restrict set,
+		sigset_t *__restrict retrieve);
+[[gnu::weak]] int sys_sigaction(int, const struct sigaction *__restrict,
+		struct sigaction *__restrict);
+// NOTE: POSIX says that behavior of timeout = nullptr is unspecified. We treat this case
+// as an infinite timeout, making sigtimedwait(..., nullptr) equivalent to sigwaitinfo(...)
+[[gnu::weak]] int sys_sigtimedwait(const sigset_t *__restrict set, siginfo_t *__restrict info, const struct timespec *__restrict timeout, int *out_signal);
+[[gnu::weak]] int sys_kill(int, int);
+[[gnu::weak]] int sys_accept(int fd, int *newfd, struct sockaddr *addr_ptr, socklen_t *addr_length, int flags);
+[[gnu::weak]] int sys_bind(int fd, const struct sockaddr *addr_ptr, socklen_t addr_length);
+[[gnu::weak]] int sys_connect(int fd, const struct sockaddr *addr_ptr, socklen_t addr_length);
+[[gnu::weak]] int sys_sockname(int fd, struct sockaddr *addr_ptr, socklen_t max_addr_length,
+		socklen_t *actual_length);
+[[gnu::weak]] int sys_peername(int fd, struct sockaddr *addr_ptr, socklen_t max_addr_length,
+	socklen_t *actual_length);
+[[gnu::weak]] int sys_gethostname(char *buffer, size_t bufsize);
+[[gnu::weak]] int sys_sethostname(const char *buffer, size_t bufsize);
+[[gnu::weak]] int sys_mkfifoat(int dirfd, const char *path, int mode);
+[[gnu::weak]] int sys_getentropy(void *buffer, size_t length);
+[[gnu::weak]] int sys_mknodat(int dirfd, const char *path, int mode, int dev);
+[[gnu::weak]] int sys_umask(mode_t mode, mode_t *old);
+
+[[gnu::weak]] int sys_before_cancellable_syscall(ucontext_t *uctx);
+[[gnu::weak]] int sys_tgkill(int tgid, int tid, int sig);
+
+[[gnu::weak]] int sys_fchownat(int dirfd, const char *pathname, uid_t owner, gid_t group, int flags);
+[[gnu::weak]] int sys_sigaltstack(const stack_t *ss, stack_t *oss);
+[[gnu::weak]] int sys_sigsuspend(const sigset_t *set);
+[[gnu::weak]] int sys_sigpending(sigset_t *set);
+[[gnu::weak]] int sys_setgroups(size_t size, const gid_t *list);
+[[gnu::weak]] int sys_memfd_create(const char *name, int flags, int *fd);
+[[gnu::weak]] int sys_madvise(void *addr, size_t length, int advice);
+[[gnu::weak]] int sys_msync(void *addr, size_t length, int flags);
+
+[[gnu::weak]] int sys_getitimer(int which, struct itimerval *curr_value);
+[[gnu::weak]] int sys_setitimer(int which, const struct itimerval *new_value, struct itimerval *old_value);
+[[gnu::weak]] int sys_timer_create(clockid_t clk, struct sigevent *__restrict evp, timer_t *__restrict res);
+[[gnu::weak]] int sys_timer_settime(timer_t t, int flags, const struct itimerspec *__restrict val, struct itimerspec *__restrict old);
+[[gnu::weak]] int sys_timer_delete(timer_t t);
+[[gnu::weak]] int sys_times(struct tms *tms, clock_t *out);
+[[gnu::weak]] int sys_uname(struct utsname *buf);
+[[gnu::weak]] int sys_pause();
+
+[[gnu::weak]] int sys_setresuid(uid_t ruid, uid_t euid, uid_t suid);
+[[gnu::weak]] int sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid);
+[[gnu::weak]] int sys_getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
+[[gnu::weak]] int sys_getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);
+[[gnu::weak]] int sys_setreuid(uid_t ruid, uid_t euid);
+[[gnu::weak]] int sys_setregid(gid_t rgid, gid_t egid);
+
+[[gnu::weak]] int sys_poll(struct pollfd *fds, nfds_t count, int timeout, int *num_events);
+
+[[gnu::weak]] int sys_if_indextoname(unsigned int index, char *name);
+[[gnu::weak]] int sys_if_nametoindex(const char *name, unsigned int *ret);
+
+[[gnu::weak]] int sys_ptsname(int fd, char *buffer, size_t length);
+[[gnu::weak]] int sys_unlockpt(int fd);
+
+[[gnu::weak]] int sys_thread_setname(void *tcb, const char *name);
+[[gnu::weak]] int sys_thread_getname(void *tcb, char *name, size_t size);
+
+[[gnu::weak]] int sys_sysconf(int num, long *ret);
+
+[[gnu::weak]] int sys_semget(key_t key, int n, int fl, int *id);
+[[gnu::weak]] int sys_semctl(int semid, int semnum, int cmd, void *semun, int *ret);
+
+[[gnu::weak]] int sys_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask);
+[[gnu::weak]] int sys_getthreadaffinity(pid_t tid, size_t cpusetsize, cpu_set_t *mask);
+
+[[gnu::weak]] int sys_setaffinity(pid_t pid, size_t cpusetsize, const cpu_set_t *mask);
+[[gnu::weak]] int sys_setthreadaffinity(pid_t tid, size_t cpusetsize, const cpu_set_t *mask);
+
+[[gnu::weak]] int sys_waitid(idtype_t idtype, id_t id, siginfo_t *info, int options);
+
+} //namespace mlibc
+
+#endif // MLIBC_POSIX_SYSDEPS
diff --git a/lib/mlibc/options/posix/include/mlibc/resolv_conf.hpp b/lib/mlibc/options/posix/include/mlibc/resolv_conf.hpp
new file mode 100644
index 0000000..2a349c7
--- /dev/null
+++ b/lib/mlibc/options/posix/include/mlibc/resolv_conf.hpp
@@ -0,0 +1,21 @@
+#ifndef _MLIBC_RESOLV_CONF
+#define _MLIBC_RESOLV_CONF
+
+#include <frg/string.hpp>
+#include <frg/optional.hpp>
+#include <mlibc/allocator.hpp>
+
+namespace mlibc {
+
+struct nameserver_data {
+	nameserver_data()
+	: name(getAllocator()) {}
+	frg::string<MemoryAllocator> name;
+	// for in the future we can also store options here
+};
+
+frg::optional<struct nameserver_data> get_nameserver();
+
+} // namespace mlibc
+
+#endif // _MLIBC_RESOLV_CONF
diff --git a/lib/mlibc/options/posix/include/mlibc/services.hpp b/lib/mlibc/options/posix/include/mlibc/services.hpp
new file mode 100644
index 0000000..10dec47
--- /dev/null
+++ b/lib/mlibc/options/posix/include/mlibc/services.hpp
@@ -0,0 +1,33 @@
+#ifndef _MLIBC_SERVICES
+#define _MLIBC_SERVICES
+
+#include <frg/small_vector.hpp>
+#include <frg/vector.hpp>
+#include <frg/string.hpp>
+#include <mlibc/allocator.hpp>
+
+namespace mlibc {
+
+// Only two services for tcp and udp
+#define SERV_MAX 2
+
+struct service_buf {
+	service_buf()
+	: name(getAllocator()), aliases(getAllocator())
+	{ }
+	int port, protocol, socktype;
+	frg::string<MemoryAllocator> name;
+	frg::vector<frg::string<MemoryAllocator>, MemoryAllocator> aliases;
+};
+
+using service_result = frg::small_vector<service_buf, SERV_MAX, MemoryAllocator>;
+
+int lookup_serv_by_name(service_result &buf, const char *name, int proto,
+		int socktype, int flags);
+
+int lookup_serv_by_port(service_result &buf, int proto, int port);
+
+
+} // namespace mlibc
+
+#endif // _MLIBC_SERVICES
diff --git a/lib/mlibc/options/posix/include/mqueue.h b/lib/mlibc/options/posix/include/mqueue.h
new file mode 100644
index 0000000..34ac990
--- /dev/null
+++ b/lib/mlibc/options/posix/include/mqueue.h
@@ -0,0 +1,26 @@
+#ifndef _MQUEUE_H
+#define _MQUEUE_H
+
+#include <abi-bits/mqueue.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef int mqd_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+int mq_getattr(mqd_t mqdes, struct mq_attr *attr);
+int mq_setattr(mqd_t mqdes, const struct mq_attr *__restrict__ newattr, struct mq_attr *__restrict__ oldattr);
+int mq_unlink(const char *name);
+mqd_t mq_open(const char *name, int flags, ...);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _MQUEUE_H */
+
diff --git a/lib/mlibc/options/posix/include/net/if.h b/lib/mlibc/options/posix/include/net/if.h
new file mode 100644
index 0000000..10016fd
--- /dev/null
+++ b/lib/mlibc/options/posix/include/net/if.h
@@ -0,0 +1,118 @@
+
+#ifndef _NET_IF_H
+#define _NET_IF_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <sys/socket.h>
+
+#define IF_NAMESIZE 16
+#define IFNAMSIZ IF_NAMESIZE
+#define ALTIFNAMSIZ 128
+#define IFALIASZ 256
+
+struct if_nameindex {
+	unsigned int if_index;
+	char *if_name;
+};
+
+struct ifmap {
+	unsigned long mem_start;
+	unsigned long mem_end;
+	unsigned short base_addr;
+	unsigned char irq;
+	unsigned char dma;
+	unsigned char port;
+};
+
+struct ifreq {
+	union {
+		char ifrn_name[IFNAMSIZ];
+	} ifr_ifrn;
+
+	union {
+		struct sockaddr ifru_addr;
+		struct sockaddr ifru_dstaddr;
+		struct sockaddr ifru_broadaddr;
+		struct sockaddr ifru_netmask;
+		struct sockaddr ifru_hwaddr;
+		short int ifru_flags;
+		int ifru_ivalue;
+		int ifru_mtu;
+		struct ifmap ifru_map;
+		char ifru_slave[IFNAMSIZ];
+		char ifru_newname[IFNAMSIZ];
+		char *ifru_data;
+	} ifr_ifru;
+};
+
+#define ifr_name	ifr_ifrn.ifrn_name
+#define ifr_hwaddr	ifr_ifru.ifru_hwaddr
+#define ifr_addr	ifr_ifru.ifru_addr
+#define ifr_dstaddr	ifr_ifru.ifru_dstaddr
+#define ifr_broadaddr	ifr_ifru.ifru_broadaddr
+#define ifr_netmask	ifr_ifru.ifru_netmask
+#define ifr_flags	ifr_ifru.ifru_flags
+#define ifr_metric	ifr_ifru.ifru_ivalue
+#define ifr_mtu		ifr_ifru.ifru_mtu
+#define ifr_map		ifr_ifru.ifru_map
+#define ifr_slave	ifr_ifru.ifru_slave
+#define ifr_data	ifr_ifru.ifru_data
+#define ifr_ifindex	ifr_ifru.ifru_ivalue
+#define ifr_bandwidth	ifr_ifru.ifru_ivalue
+#define ifr_qlen	ifr_ifru.ifru_ivalue
+#define ifr_newname	ifr_ifru.ifru_newname
+
+struct ifconf {
+	int ifc_len;
+	union {
+		char *ifcu_buf;
+		struct ifreq *ifcu_req;
+	} ifc_ifcu;
+};
+
+#define ifc_buf ifc_ifcu.ifcu_buf
+#define ifc_req ifc_ifcu.ifcu_req
+
+#ifndef __MLIBC_ABI_ONLY
+
+void if_freenameindex(struct if_nameindex *);
+char *if_indextoname(unsigned int, char *);
+struct if_nameindex *if_nameindex(void);
+unsigned int if_nametoindex(const char *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#define IFHWADDRLEN 6
+
+#define IFF_UP 0x1
+#define IFF_BROADCAST 0x2
+#define IFF_DEBUG 0x4
+#define IFF_LOOPBACK 0x8
+#define IFF_POINTOPOINT 0x10
+#define IFF_NOTRAILERS 0x20
+#define IFF_RUNNING 0x40
+#define IFF_NOARP 0x80
+#define IFF_PROMISC 0x100
+#define IFF_ALLMULTI 0x200
+#define IFF_MASTER 0x400
+#define IFF_SLAVE 0x800
+#define IFF_MULTICAST 0x1000
+#define IFF_PORTSEL 0x2000
+#define IFF_AUTOMEDIA 0x4000
+#define IFF_DYNAMIC 0x8000
+#define IFF_LOWER_UP 0x10000
+#define IFF_DORMANT 0x20000
+#define IFF_ECHO 0x40000
+#define IFF_VOLATILE (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_BROADCAST| \
+        IFF_ECHO|IFF_MASTER|IFF_SLAVE|IFF_RUNNING|IFF_LOWER_UP|IFF_DORMANT)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NET_IF_H
+
+
diff --git a/lib/mlibc/options/posix/include/net/if_arp.h b/lib/mlibc/options/posix/include/net/if_arp.h
new file mode 100644
index 0000000..de8a0c2
--- /dev/null
+++ b/lib/mlibc/options/posix/include/net/if_arp.h
@@ -0,0 +1,103 @@
+#ifndef _NET_IF_ARP_H
+#define _NET_IF_ARP_H
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdint.h>
+
+#define ARPOP_REQUEST 1
+#define ARPOP_REPLY 2
+#define ARPOP_RREQUEST 3
+#define ARPOP_RREPLY 4
+#define ARPOP_InREQUEST 8
+#define ARPOP_InREPLY 9
+#define ARPOP_NAK 10
+
+#define ARPHRD_NETROM 0
+#define ARPHRD_ETHER 1
+#define ARPHRD_EETHER 2
+#define ARPHRD_AX25 3
+#define ARPHRD_PRONET 4
+#define ARPHRD_CHAOS 5
+#define ARPHRD_IEEE802 6
+#define ARPHRD_ARCNET 7
+#define ARPHRD_APPLETLK 8
+#define ARPHRD_DLCI 15
+#define ARPHRD_ATM 19
+#define ARPHRD_METRICOM 23
+#define ARPHRD_IEEE1394 24
+#define ARPHRD_EUI64 27
+#define ARPHRD_INFINIBAND 32
+#define ARPHRD_SLIP 256
+#define ARPHRD_CSLIP 257
+#define ARPHRD_SLIP6 258
+#define ARPHRD_CSLIP6 259
+#define ARPHRD_RSRVD 260
+#define ARPHRD_ADAPT 264
+#define ARPHRD_ROSE 270
+#define ARPHRD_X25 271
+#define ARPHRD_HWX25 272
+#define ARPHRD_CAN 280
+#define ARPHRD_PPP 512
+#define ARPHRD_CISCO 513
+#define ARPHRD_HDLC ARPHRD_CISCO
+#define ARPHRD_LAPB 516
+#define ARPHRD_DDCMP 517
+#define ARPHRD_RAWHDLC 518
+#define ARPHRD_RAWIP 519
+
+#define ARPHRD_TUNNEL 768
+#define ARPHRD_TUNNEL6 769
+#define ARPHRD_FRAD 770
+#define ARPHRD_SKIP 771
+#define ARPHRD_LOOPBACK 772
+#define ARPHRD_LOCALTLK 773
+#define ARPHRD_FDDI 774
+#define ARPHRD_BIF 775
+#define ARPHRD_SIT 776
+#define ARPHRD_IPDDP 777
+#define ARPHRD_IPGRE 778
+#define ARPHRD_PIMREG 779
+#define ARPHRD_HIPPI 780
+#define ARPHRD_ASH 781
+#define ARPHRD_ECONET 782
+#define ARPHRD_IRDA 783
+#define ARPHRD_FCPP 784
+#define ARPHRD_FCAL 785
+#define ARPHRD_FCPL 786
+#define ARPHRD_FCFABRIC 787
+#define ARPHRD_IEEE802_TR 800
+#define ARPHRD_IEEE80211 801
+#define ARPHRD_IEEE80211_PRISM 802
+#define ARPHRD_IEEE80211_RADIOTAP 803
+#define ARPHRD_IEEE802154 804
+#define ARPHRD_IEEE802154_MONITOR 805
+#define ARPHRD_PHONET 820
+#define ARPHRD_PHONET_PIPE 821
+#define ARPHRD_CAIF 822
+#define ARPHRD_IP6GRE 823
+#define ARPHRD_NETLINK 824
+#define ARPHRD_6LOWPAN 825
+#define ARPHRD_VSOCKMON 826
+
+#define ARPHRD_VOID 0xFFFF
+#define ARPHRD_NONE 0xFFFE
+
+struct arphdr {
+	uint16_t ar_hrd;
+	uint16_t ar_pro;
+	uint8_t ar_hln;
+	uint8_t ar_pln;
+	uint16_t ar_op;
+};
+
+struct arpreq {
+	struct sockaddr arp_pa;
+	struct sockaddr arp_ha;
+	int arp_flags;
+	struct sockaddr arp_netmask;
+	char arp_dev[16];
+};
+
+#endif // _NET_IF_ARP_H
+
diff --git a/lib/mlibc/options/posix/include/netdb.h b/lib/mlibc/options/posix/include/netdb.h
new file mode 100644
index 0000000..368c74f
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netdb.h
@@ -0,0 +1,148 @@
+#ifndef _NETDB_H
+#define _NETDB_H
+
+#include <stdint.h>
+#include <bits/size_t.h>
+#include <bits/posix/in_port_t.h>
+#include <bits/posix/in_addr_t.h>
+#include <abi-bits/socklen_t.h>
+
+#define AI_PASSIVE 0x01
+#define AI_CANONNAME 0x02
+#define AI_NUMERICHOST 0x04
+#define AI_V4MAPPED 0x08
+#define AI_ALL 0x10
+#define AI_ADDRCONFIG 0x20
+#define AI_NUMERICSERV 0x40
+
+#define NI_NOFQDN 0x01
+#define NI_NUMERICHOST 0x02
+#define NI_NAMEREQD 0x04
+#define NI_NUMERICSCOPE 0x08
+#define NI_DGRAM 0x10
+
+#define NI_NUMERICSERV 2
+#define NI_MAXSERV 32
+#define NI_IDN 32
+
+#define NI_MAXHOST 1025
+
+#define EAI_AGAIN 1
+#define EAI_BADFLAGS 2
+#define EAI_FAIL 3
+#define EAI_FAMILY 4
+#define EAI_MEMORY 5
+#define EAI_NONAME 6
+#define EAI_SERVICE 7
+#define EAI_SOCKTYPE 8
+#define EAI_SYSTEM 9
+#define EAI_OVERFLOW 10
+#define EAI_NODATA 11
+#define EAI_ADDRFAMILY 12
+
+#define HOST_NOT_FOUND 1
+#define TRY_AGAIN      2
+#define NO_RECOVERY    3
+#define NO_DATA        4
+#define NO_ADDRESS     NO_DATA
+
+#define IPPORT_RESERVED 1024
+
+#define _PATH_SERVICES "/etc/services"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int *__h_errno_location(void);
+#define h_errno (*__h_errno_location())
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+struct hostent {
+	char *h_name;
+	char **h_aliases;
+	int h_addrtype;
+	int h_length;
+	char **h_addr_list;
+};
+
+#define h_addr h_addr_list[0] // Required by some programs
+
+struct netent {
+	char *n_name;
+	char **n_aliases;
+	int n_addrtype;
+	uint32_t n_net;
+};
+
+struct protoent {
+	char *p_name;
+	char **p_aliases;
+	int p_proto;
+};
+
+struct servent {
+	char *s_name;
+	char **s_aliases;
+	int s_port;
+	char *s_proto;
+};
+
+struct addrinfo {
+	int ai_flags;
+	int ai_family;
+	int ai_socktype;
+	int ai_protocol;
+	socklen_t ai_addrlen;
+	struct sockaddr *ai_addr;
+	char *ai_canonname;
+	struct addrinfo *ai_next;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+void endhostent(void);
+void endnetent(void);
+void endprotoent(void);
+void endservent(void);
+void freeaddrinfo(struct addrinfo *);
+const char *gai_strerror(int);
+int getaddrinfo(const char *__restrict, const char *__restrict,
+		const struct addrinfo *__restrict, struct addrinfo **__restrict);
+struct hostent *gethostent(void);
+struct hostent *gethostbyname(const char *);
+struct hostent *gethostbyname2(const char *, int);
+struct hostent *gethostbyaddr(const void *, socklen_t, int);
+int gethostbyaddr_r(const void *__restrict, socklen_t, int, struct hostent *__restrict,
+					char *__restrict, size_t, struct hostent **__restrict, int *__restrict);
+int gethostbyname_r(const char *__restrict, struct hostent *__restrict, char *__restrict, size_t,
+					struct hostent **__restrict, int *__restrict);
+int getnameinfo(const struct sockaddr *__restrict, socklen_t,
+		char *__restrict, socklen_t, char *__restrict, socklen_t, int);
+struct netent *getnetbyaddr(uint32_t, int);
+struct netent *getnetbyname(const char *);
+struct netent *getnetent(void);
+struct protoent *getprotobyname(const char *);
+struct protoent *getprotobynumber(int);
+struct protoent *getprotoent(void);
+struct servent *getservbyname(const char *, const char *);
+struct servent *getservbyport(int, const char *);
+struct servent *getservent(void);
+void sethostent(int);
+void setnetent(int);
+void setprotoent(int);
+void setservent(int);
+
+// Deprecated GNU extension
+const char *hstrerror(int err);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETDB_H
diff --git a/lib/mlibc/options/posix/include/netinet/icmp6.h b/lib/mlibc/options/posix/include/netinet/icmp6.h
new file mode 100644
index 0000000..7dfe237
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/icmp6.h
@@ -0,0 +1,139 @@
+#ifndef _NETINET_ICMP6_H
+#define _NETINET_ICMP6_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <abi-bits/in.h>
+#include <mlibc-config.h>
+
+#if __MLIBC_GLIBC_OPTION
+#include <bits/glibc/glibc_icmp6.h>
+#endif // __MLIBC_GLIBC_OPTION
+
+#define ICMP6_FILTER 1
+
+#define ICMP6_FILTER_BLOCK 1
+#define ICMP6_FILTER_PASS 2
+#define ICMP6_FILTER_BLOCKOTHERS 3
+#define ICMP6_FILTER_PASSONLY 4
+#define ICMP6_ECHO_REQUEST 128
+
+struct icmp6_filter {
+	uint32_t icmp6_filt[8];
+};
+
+struct icmp6_hdr {
+	uint8_t icmp6_type;
+	uint8_t icmp6_code;
+	uint16_t icmp6_cksum;
+	union {
+		uint32_t icmp6_un_data32[1];
+		uint16_t icmp6_un_data16[2];
+		uint8_t icmp6_un_data8[4];
+	} icmp6_dataun;
+};
+
+#define icmp6_data32 icmp6_dataun.icmp6_un_data32
+#define icmp6_data16 icmp6_dataun.icmp6_un_data16
+#define icmp6_data8 icmp6_dataun.icmp6_un_data8
+
+#define icmp6_pptr icmp6_data32[0]
+#define icmp6_mtu icmp6_data32[0]
+#define icmp6_id icmp6_data16[0]
+#define icmp6_seq icmp6_data16[1]
+#define icmp6_maxdelay icmp6_data16[0]
+
+#define ICMP6_FILTER_WILLPASS(type, filterp) \
+	((((filterp)->icmp6_filt[(type) >> 5]) & (1U << ((type) & 31))) == 0)
+
+#define ICMP6_FILTER_WILLBLOCK(type, filterp) \
+	((((filterp)->icmp6_filt[(type) >> 5]) & (1U << ((type) & 31))) != 0)
+
+#define ICMP6_FILTER_SETPASS(type, filterp) \
+	((((filterp)->icmp6_filt[(type) >> 5]) &= ~(1U << ((type) & 31))))
+
+#define ICMP6_FILTER_SETBLOCK(type, filterp) \
+	((((filterp)->icmp6_filt[(type) >> 5]) |=  (1U << ((type) & 31))))
+
+#define ICMP6_FILTER_SETPASSALL(filterp) \
+	memset (filterp, 0, sizeof (struct icmp6_filter));
+
+#define ICMP6_FILTER_SETBLOCKALL(filterp) \
+	memset (filterp, 0xFF, sizeof (struct icmp6_filter));
+
+#define ND_ROUTER_SOLICIT 133
+#define ND_ROUTER_ADVERT 134
+#define ND_NEIGHBOR_SOLICIT 135
+#define ND_NEIGHBOR_ADVERT 136
+#define ND_REDIRECT 137
+
+struct nd_router_solicit {
+	struct icmp6_hdr nd_rs_hdr;
+};
+
+#define nd_rs_type nd_rs_hdr.icmp6_type
+#define nd_rs_code nd_rs_hdr.icmp6_code
+#define nd_rs_cksum nd_rs_hdr.icmp6_cksum
+#define nd_rs_reserved nd_rs_hdr.icmp6_data32[0]
+
+struct nd_router_advert {
+	struct icmp6_hdr nd_ra_hdr;
+	uint32_t nd_ra_reachable;
+	uint32_t nd_ra_retransmit;
+};
+
+struct nd_opt_hdr {
+	uint8_t nd_opt_type;
+	uint8_t nd_opt_len;
+};
+
+#define ND_OPT_SOURCE_LINKADDR 1
+#define ND_OPT_TARGET_LINKADDR 2
+#define ND_OPT_PREFIX_INFORMATION 3
+#define ND_OPT_REDIRECTED_HEADER 4
+#define ND_OPT_MTU 5
+#define ND_OPT_RTR_ADV_INTERVAL 7
+#define ND_OPT_HOME_AGENT_INFO 8
+
+struct nd_opt_prefix_info {
+	uint8_t nd_opt_pi_type;
+	uint8_t nd_opt_pi_len;
+	uint8_t nd_opt_pi_prefix_len;
+	uint8_t nd_opt_pi_flags_reserved;
+	uint32_t nd_opt_pi_valid_time;
+	uint32_t nd_opt_pi_preferred_time;
+	uint32_t nd_opt_pi_reserved2;
+	struct in6_addr nd_opt_pi_prefix;
+};
+
+#define ND_OPT_PI_FLAG_RADDR 0x20
+#define ND_OPT_PI_FLAG_AUTO 0x40
+#define ND_OPT_PI_FLAG_ONLINK 0x80
+
+#define nd_ra_type nd_ra_hdr.icmp6_type
+#define nd_ra_code nd_ra_hdr.icmp6_code
+#define nd_ra_cksum nd_ra_hdr.icmp6_cksum
+#define nd_ra_curhoplimit nd_ra_hdr.icmp6_data8[0]
+#define nd_ra_flags_reserved nd_ra_hdr.icmp6_data8[1]
+#define nd_ra_router_lifetime nd_ra_hdr.icmp6_data16[1]
+
+#define ND_RA_FLAG_HOME_AGENT 0x20
+#define ND_RA_FLAG_OTHER 0x40
+#define ND_RA_FLAG_MANAGED 0x80
+
+struct nd_opt_mtu {
+	uint8_t nd_opt_mtu_type;
+	uint8_t nd_opt_mtu_len;
+	uint16_t nd_opt_mtu_reserved;
+	uint32_t nd_opt_mtu_mtu;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_ICMP6_H
+
diff --git a/lib/mlibc/options/posix/include/netinet/if_ether.h b/lib/mlibc/options/posix/include/netinet/if_ether.h
new file mode 100644
index 0000000..c4ce173
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/if_ether.h
@@ -0,0 +1,105 @@
+#ifndef _NETINET_IF_ETHER_H
+#define _NETINET_IF_ETHER_H
+
+#include <net/if_arp.h>
+
+#define ETH_ALEN 6
+#define ETH_HLEN 14
+#define ETH_ZLEN 60
+#define ETH_FRAME_LEN 1514
+#define ETH_FCS_LEN 4
+
+#define ETH_P_LOOP 0x0060
+#define ETH_P_PUP 0x0200
+#define ETH_P_PUPAT 0x0201
+#define ETH_P_IP 0x0800
+#define ETH_P_X25 0x0805
+#define ETH_P_ARP 0x0806
+#define ETH_P_BPQ 0x08FF
+#define ETH_P_IEEEPUP 0x0a00
+#define ETH_P_IEEEPUPAT 0x0a01
+#define ETH_P_BATMAN 0x4305
+#define ETH_P_DEC 0x6000
+#define ETH_P_DNA_DL 0x6001
+#define ETH_P_DNA_RC 0x6002
+#define ETH_P_DNA_RT 0x6003
+#define ETH_P_LAT 0x6004
+#define ETH_P_DIAG 0x6005
+#define ETH_P_CUST 0x6006
+#define ETH_P_SCA 0x6007
+#define ETH_P_TEB 0x6558
+#define ETH_P_RARP 0x8035
+#define ETH_P_ATALK 0x809B
+#define ETH_P_AARP 0x80F3
+#define ETH_P_8021Q 0x8100
+#define ETH_P_IPX 0x8137
+#define ETH_P_IPV6 0x86DD
+#define ETH_P_PAUSE 0x8808
+#define ETH_P_SLOW 0x8809
+#define ETH_P_WCCP 0x883E
+#define ETH_P_MPLS_UC 0x8847
+#define ETH_P_MPLS_MC 0x8848
+#define ETH_P_ATMMPOA 0x884c
+#define ETH_P_PPP_DISC 0x8863
+#define ETH_P_PPP_SES 0x8864
+#define ETH_P_LINK_CTL 0x886c
+#define ETH_P_ATMFATE 0x8884
+#define ETH_P_PAE 0x888E
+#define ETH_P_AOE 0x88A2
+#define ETH_P_8021AD 0x88A8
+#define ETH_P_802_EX1 0x88B5
+#define ETH_P_TIPC 0x88CA
+#define ETH_P_8021AH 0x88E7
+#define ETH_P_MVRP 0x88F5
+#define ETH_P_1588 0x88F7
+#define ETH_P_PRP 0x88FB
+#define ETH_P_FCOE 0x8906
+#define ETH_P_TDLS 0x890D
+#define ETH_P_FIP 0x8914
+#define ETH_P_80221 0x8917
+#define ETH_P_LOOPBACK 0x9000
+#define ETH_P_QINQ1 0x9100
+#define ETH_P_QINQ2 0x9200
+#define ETH_P_QINQ3 0x9300
+#define ETH_P_EDSA 0xDADA
+#define ETH_P_AF_IUCV 0xFBFB
+
+#define ETH_P_802_3_MIN 0x0600
+
+#define ETH_P_802_3 0x0001
+#define ETH_P_AX25 0x0002
+#define ETH_P_ALL 0x0003
+#define ETH_P_802_2 0x0004
+#define ETH_P_SNAP 0x0005
+#define ETH_P_DDCMP 0x0006
+#define ETH_P_WAN_PPP 0x0007
+#define ETH_P_PPP_MP 0x0008
+#define ETH_P_LOCALTALK 0x0009
+#define ETH_P_CAN 0x000C
+#define ETH_P_CANFD 0x000D
+#define ETH_P_PPPTALK 0x0010
+#define ETH_P_TR_802_2 0x0011
+#define ETH_P_MOBITEX 0x0015
+#define ETH_P_CONTROL 0x0016
+#define ETH_P_IRDA 0x0017
+#define ETH_P_ECONET 0x0018
+#define ETH_P_HDLC 0x0019
+#define ETH_P_ARCNET 0x001A
+#define ETH_P_DSA 0x001B
+#define ETH_P_TRAILER 0x001C
+#define ETH_P_PHONET 0x00F5
+#define ETH_P_IEEE802154 0x00F6
+#define ETH_P_CAIF 0x00F7
+
+#include <net/ethernet.h>
+#include <net/if_arp.h>
+
+struct ether_arp {
+	struct arphdr ea_hdr;
+	uint8_t arp_sha[ETH_ALEN];
+	uint8_t arp_spa[4];
+	uint8_t arp_tha[ETH_ALEN];
+	uint8_t arp_tpa[4];
+};
+
+#endif //_NETINET_IF_ETHER_H
diff --git a/lib/mlibc/options/posix/include/netinet/in.h b/lib/mlibc/options/posix/include/netinet/in.h
new file mode 100644
index 0000000..9a42c47
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/in.h
@@ -0,0 +1,118 @@
+
+#ifndef _NETINET_IN_H
+#define _NETINET_IN_H
+
+#include <stdint.h>
+#include <endian.h>
+#include <sys/socket.h> // struct sockaddr
+#include <abi-bits/socket.h>
+#include <abi-bits/in.h>
+#include <arpa/inet.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+extern const struct in6_addr in6addr_any;
+extern const struct in6_addr in6addr_loopback;
+
+uint32_t htonl(uint32_t);
+uint16_t htons(uint16_t);
+uint32_t ntohl(uint32_t);
+uint16_t ntohs(uint16_t);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#define IN6_IS_ADDR_UNSPECIFIED(a) ({ \
+    uint32_t *_a = (uint32_t *)(((struct in6_addr *) a)->s6_addr); \
+    !_a[0] && \
+    !_a[1] && \
+    !_a[2] && \
+    !_a[3];  \
+})
+#define IN6_IS_ADDR_LOOPBACK(a) ({ \
+    uint32_t *_a = (uint32_t *)(((struct in6_addr *) a)->s6_addr); \
+    !_a[0] && \
+    !_a[1] && \
+    !_a[2] && \
+     _a[3] == htonl(0x0001); \
+})
+#define IN6_IS_ADDR_MULTICAST(a) (((const uint8_t *) (a))[0] == 0xff)
+#define IN6_IS_ADDR_LINKLOCAL(a) ({ \
+    uint32_t *_a = (uint32_t *)(((struct in6_addr *) a)->s6_addr); \
+    _a[0] & htonl(0xffc00000) == htonl(0xfe800000); \
+})
+#define IN6_IS_ADDR_SITELOCAL(a) ({ \
+    uint32_t *_a = (uint32_t *)(((struct in6_addr *) a)->s6_addr); \
+    _a[0] & htonl(0xffc00000) == htonl(0xfec00000); \
+})
+#define IN6_IS_ADDR_V4MAPPED(a) ({ \
+    uint32_t *_a = (uint32_t *)(((struct in6_addr *) a)->s6_addr); \
+    !_a[0] && \
+    !_a[1] && \
+     _a[2] == htonl(0xffff); \
+})
+#define __ARE_4_BYTE_EQUAL(a, b) \
+	((a)[0] == (b)[0] && (a)[1] == (b)[1] && (a)[2] == (b)[2] && \
+	 (a)[3] == (b)[3] && (a)[4] == (b)[4])
+#define IN6_ARE_ADDR_EQUAL(a, b) \
+	__ARE_4_BYTE_EQUAL((const uint32_t *)(a), (const uint32_t *)(b))
+
+#define IN6_IS_ADDR_V4COMPAT(a) ({ \
+	uint32_t *_a = (uint32_t *)(((struct in6_addr *) a)->s6_addr); \
+	uint8_t *_a8 = (uint8_t *)(((struct in6_addr *) a)->s6_addr); \
+	!_a[0] && !_a[1] && !_a[2] && (_a8[15] > 1); \
+})
+#define IN6_IS_ADDR_MC_NODELOCAL(a) ({ \
+    (IN6_IS_ADDR_MULTICAST(a) && \
+    ((((const uint8_t *)(a))[1] & 0xf) == 0x1)); \
+})
+#define IN6_IS_ADDR_MC_LINKLOCAL(a) ({ \
+    (IN6_IS_ADDR_MULTICAST(a) && \
+    ((((const uint8_t *)(a))[1] & 0xf) == 0x2)); \
+})
+#define IN6_IS_ADDR_MC_SITELOCAL(a) ({ \
+    (IN6_IS_ADDR_MULTICAST(a) && \
+    ((((const uint8_t *)(a))[1] & 0xf) == 0x5)); \
+})
+#define IN6_IS_ADDR_MC_ORGLOCAL(a) ({ \
+    (IN6_IS_ADDR_MULTICAST(a) && \
+    ((((const uint8_t *)(a))[1] & 0xf) == 0x8)); \
+})
+#define IN6_IS_ADDR_MC_GLOBAL(a) ({ \
+    (IN6_IS_ADDR_MULTICAST(a) && \
+    ((((const uint8_t *)(a))[1] & 0xf) == 0xe)); \
+})
+
+#define IN_CLASSA(a) ((((in_addr_t)(a)) & 0x80000000) == 0)
+#define IN_CLASSA_NET 0xff000000
+#define IN_CLASSA_NSHIFT 24
+#define IN_CLASSA_HOST (0xffffffff & ~IN_CLASSA_NET)
+#define IN_CLASSA_MAX 128
+#define IN_CLASSB(a) ((((in_addr_t)(a)) & 0xc0000000) == 0x80000000)
+#define IN_CLASSB_NET 0xffff0000
+#define IN_CLASSB_NSHIFT 16
+#define IN_CLASSB_HOST (0xffffffff & ~IN_CLASSB_NET)
+#define IN_CLASSB_MAX 65536
+#define IN_CLASSC(a) ((((in_addr_t)(a)) & 0xe0000000) == 0xc0000000)
+#define IN_CLASSC_NET 0xffffff00
+#define IN_CLASSC_NSHIFT 8
+#define IN_CLASSC_HOST (0xffffffff & ~IN_CLASSC_NET)
+#define IN_CLASSD(a) ((((in_addr_t)(a)) & 0xf0000000) == 0xe0000000)
+#define IN_MULTICAST(a) IN_CLASSD(a)
+#define IN_EXPERIMENTAL(a) ((((in_addr_t)(a)) & 0xe0000000) == 0xe0000000)
+#define IN_BADCLASS(a) ((((in_addr_t)(a)) & 0xf0000000) == 0xf0000000)
+
+#define IN_LOOPBACKNET 127
+
+#define MCAST_EXCLUDE 0
+#define MCAST_INCLUDE 1
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_IN_H
+
diff --git a/lib/mlibc/options/posix/include/netinet/ip.h b/lib/mlibc/options/posix/include/netinet/ip.h
new file mode 100644
index 0000000..161aa18
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/ip.h
@@ -0,0 +1,75 @@
+
+#ifndef _NETINET_IP_H
+#define _NETINET_IP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <sys/types.h>
+#include <netinet/in.h>
+
+#define IPTOS_TOS_MASK 0x1E
+#define IPTOS_TOS(tos) ((tos) & IPTOS_TOS_MASK)
+#define IPTOS_LOWDELAY 0x10
+#define IPTOS_THROUGHPUT 0x08
+#define IPTOS_RELIABILITY 0x04
+#define IPTOS_LOWCOST 0x02
+#define IPTOS_MINCOST IPTOS_LOWCOST
+#define IPTOS_CLASS_CS4 0x80
+#define IPTOS_CLASS_CS6 0xC0
+
+#define IPDEFTTL 64
+
+struct ip {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	unsigned int ip_hl:4;
+	unsigned int ip_v:4;
+#endif
+#if __BYTE_ORDER == __BIG_ENDIAN
+	unsigned int ip_v:4;
+	unsigned int ip_hl:4;
+#endif
+	uint8_t ip_tos;
+	unsigned short ip_len;
+	unsigned short ip_id;
+	unsigned short ip_off;
+#define IP_RF 0x8000
+#define IP_DF 0x4000
+#define IP_MF 0x2000
+#define IP_OFFMASK 0x1fff
+	uint8_t ip_ttl;
+	uint8_t ip_p;
+	unsigned short ip_sum;
+	struct in_addr ip_src, ip_dst;
+};
+
+#define IPVERSION 4
+
+struct iphdr {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	unsigned int ihl:4;
+	unsigned int version:4;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+	unsigned int version:4;
+	unsigned int ihl:4;
+#else
+# error	"Please fix <endian.h>"
+#endif
+	uint8_t tos;
+	uint16_t tot_len;
+	uint16_t id;
+	uint16_t frag_off;
+	uint8_t ttl;
+	uint8_t protocol;
+	uint16_t check;
+	uint32_t saddr;
+	uint32_t daddr;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_IP_H
+
diff --git a/lib/mlibc/options/posix/include/netinet/ip6.h b/lib/mlibc/options/posix/include/netinet/ip6.h
new file mode 100644
index 0000000..88f0cb6
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/ip6.h
@@ -0,0 +1,28 @@
+#ifndef _NETINET_IP6_H
+#define _NETINET_IP6_H
+
+#include <netinet/in.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ip6_hdr {
+	union {
+		struct ip6_hdrctl {
+			uint32_t ip6_un1_flow;
+			uint16_t ip6_un1_plen;
+			uint8_t  ip6_un1_nxt;
+			uint8_t  ip6_un1_hlim;
+		} ip6_un1;
+		uint8_t ip6_un2_vfc;
+	} ip6_ctlun;
+	struct in6_addr ip6_src;
+	struct in6_addr ip6_dst;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_IP6_H
diff --git a/lib/mlibc/options/posix/include/netinet/ip_icmp.h b/lib/mlibc/options/posix/include/netinet/ip_icmp.h
new file mode 100644
index 0000000..56615e4
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/ip_icmp.h
@@ -0,0 +1,84 @@
+#ifndef _NETINET_ICMP_H
+#define _NETINET_ICMP_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+
+#define ICMP_ECHOREPLY 0
+#define ICMP_ECHO 8
+#define ICMP_ADVLENMIN (8 + sizeof(struct ip) + 8)
+
+struct icmp_ra_addr {
+	uint32_t ira_addr;
+	uint32_t ira_preference;
+};
+
+struct icmp {
+	uint8_t icmp_type;
+	uint8_t icmp_code;
+	uint16_t icmp_cksum;
+	union {
+		unsigned char ih_pptr;
+		struct in_addr ih_gwaddr;
+		struct ih_idseq {
+			uint16_t icd_id;
+			uint16_t icd_seq;
+		} ih_idseq;
+		uint32_t ih_void;
+		
+		struct ih_pmtu {
+			uint16_t ipm_void;
+			uint16_t ipm_nextmtu;
+		} ih_pmtu;
+		
+		struct ih_rtradv {
+			uint8_t irt_num_addrs;
+			uint8_t irt_wpa;
+			uint16_t irt_lifetime;
+		} ih_rtradv;
+	} icmp_hun;
+	union {
+		struct {
+			uint32_t its_otime;
+			uint32_t its_rtime;
+			uint32_t its_ttime;
+		} id_ts;
+		struct {
+			struct ip idi_ip;
+		} id_ip;
+		struct icmp_ra_addr id_radv;
+		uint32_t id_mask;
+		uint8_t id_data[1];
+	} icmp_dun;
+};
+
+#define	icmp_pptr icmp_hun.ih_pptr
+#define	icmp_gwaddr	icmp_hun.ih_gwaddr
+#define	icmp_id	icmp_hun.ih_idseq.icd_id
+#define	icmp_seq icmp_hun.ih_idseq.icd_seq
+#define	icmp_void icmp_hun.ih_void
+#define	icmp_pmvoid	icmp_hun.ih_pmtu.ipm_void
+#define	icmp_nextmtu icmp_hun.ih_pmtu.ipm_nextmtu
+#define	icmp_num_addrs icmp_hun.ih_rtradv.irt_num_addrs
+#define	icmp_wpa icmp_hun.ih_rtradv.irt_wpa
+#define	icmp_lifetime icmp_hun.ih_rtradv.irt_lifetime
+
+#define	icmp_otime icmp_dun.id_ts.its_otime
+#define	icmp_rtime icmp_dun.id_ts.its_rtime
+#define	icmp_ttime icmp_dun.id_ts.its_ttime
+#define	icmp_ip	icmp_dun.id_ip.idi_ip
+#define	icmp_radv icmp_dun.id_radv
+#define	icmp_mask icmp_dun.id_mask
+#define	icmp_data icmp_dun.id_data
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_ICMP_H
diff --git a/lib/mlibc/options/posix/include/netinet/tcp.h b/lib/mlibc/options/posix/include/netinet/tcp.h
new file mode 100644
index 0000000..9d64d7a
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/tcp.h
@@ -0,0 +1,37 @@
+#ifndef _NETINET_TCP_H
+#define _NETINET_TCP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Define some macros using same ABI as Linux
+#define TCP_NODELAY 1
+#define TCP_MAXSEG 2
+#define TCP_KEEPIDLE 4
+#define TCP_KEEPINTVL 5
+#define TCP_KEEPCNT 6
+#define TCP_DEFER_ACCEPT 9
+#define TCP_CONGESTION 13
+#define TCP_FASTOPEN 23
+
+#define TCP_ESTABLISHED 1
+#define TCP_SYN_SENT 2
+#define TCP_SYN_RECV 3
+#define TCP_FIN_WAIT1 4
+#define TCP_FIN_WAIT2 5
+#define TCP_TIME_WAIT 6
+#define TCP_CLOSE 7
+#define TCP_CLOSE_WAIT 8
+#define TCP_LAST_ACK 9
+#define TCP_LISTEN 10
+#define TCP_CLOSING 11
+#define TCP_QUICKACK 12
+
+#define SOL_TCP 6
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_TCP_H
diff --git a/lib/mlibc/options/posix/include/netinet/udp.h b/lib/mlibc/options/posix/include/netinet/udp.h
new file mode 100644
index 0000000..5cc887d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/netinet/udp.h
@@ -0,0 +1,31 @@
+#ifndef _NETINET_UDP_H
+#define _NETINET_UDP_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct udphdr {
+        union {
+                struct {
+                        uint16_t uh_sport;
+                        uint16_t uh_dport;
+                        uint16_t uh_ulen;
+                        uint16_t uh_sum;
+                };
+                struct {
+                        uint16_t source;
+                        uint16_t dest;
+                        uint16_t len;
+                        uint16_t check;
+                };
+        };
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _NETINET_UDP_H
diff --git a/lib/mlibc/options/posix/include/nl_types.h b/lib/mlibc/options/posix/include/nl_types.h
new file mode 100644
index 0000000..f0099ba
--- /dev/null
+++ b/lib/mlibc/options/posix/include/nl_types.h
@@ -0,0 +1,6 @@
+#ifndef NL_TYPES_H
+#define NL_TYPES_H
+
+
+
+#endif // NL_TYPES_H 
\ No newline at end of file
diff --git a/lib/mlibc/options/posix/include/poll.h b/lib/mlibc/options/posix/include/poll.h
new file mode 100644
index 0000000..7550015
--- /dev/null
+++ b/lib/mlibc/options/posix/include/poll.h
@@ -0,0 +1,6 @@
+#ifndef _POLL_H
+#define _POLL_H
+
+#include <sys/poll.h>
+
+#endif // _POLL_H
diff --git a/lib/mlibc/options/posix/include/pthread.h b/lib/mlibc/options/posix/include/pthread.h
new file mode 100644
index 0000000..739f607
--- /dev/null
+++ b/lib/mlibc/options/posix/include/pthread.h
@@ -0,0 +1,325 @@
+
+#ifndef _PTHREAD_H
+#define _PTHREAD_H
+
+#include <abi-bits/clockid_t.h>
+#include <bits/cpu_set.h>
+// TODO: pthread is not required to define size_t.
+#include <bits/size_t.h>
+#include <bits/posix/pthread_t.h>
+#include <bits/threads.h>
+#include <mlibc-config.h>
+
+#include <signal.h>
+#include <stdint.h>
+
+// pthread.h is required to include sched.h and time.h
+#include <sched.h>
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define PTHREAD_CREATE_JOINABLE __MLIBC_THREAD_CREATE_JOINABLE
+#define PTHREAD_CREATE_DETACHED __MLIBC_THREAD_CREATE_DETACHED
+
+// Values for pthread_attr_{get,set}scope
+#define PTHREAD_SCOPE_SYSTEM 0
+#define PTHREAD_SCOPE_PROCESS 1
+
+// Values for pthread_attr_{get,set}inheritsched
+#define PTHREAD_INHERIT_SCHED 0
+#define PTHREAD_EXPLICIT_SCHED 1
+
+// values for pthread_{get,set}canceltype().
+#define PTHREAD_CANCEL_DEFERRED 0
+#define PTHREAD_CANCEL_ASYNCHRONOUS 1
+
+// values for pthread_{get,set}cancelstate().
+#define PTHREAD_CANCEL_ENABLE 0
+#define PTHREAD_CANCEL_DISABLE 1
+
+// values for pthread_mutexattr_{get,set}type().
+#define PTHREAD_MUTEX_DEFAULT __MLIBC_THREAD_MUTEX_DEFAULT
+#define PTHREAD_MUTEX_NORMAL __MLIBC_THREAD_MUTEX_NORMAL
+#define PTHREAD_MUTEX_ERRORCHECK __MLIBC_THREAD_MUTEX_ERRORCHECK
+#define PTHREAD_MUTEX_RECURSIVE __MLIBC_THREAD_MUTEX_RECURSIVE
+
+// values for pthread_mutexattr_{get,set}robust().
+#define PTHREAD_MUTEX_STALLED __MLIBC_THREAD_MUTEX_STALLED
+#define PTHREAD_MUTEX_ROBUST __MLIBC_THREAD_MUTEX_ROBUST
+
+// values for pthread_mutexattr_{get,set}pshared().
+#define PTHREAD_PROCESS_PRIVATE __MLIBC_THREAD_PROCESS_PRIVATE
+#define PTHREAD_PROCESS_SHARED __MLIBC_THREAD_PROCESS_SHARED
+
+// Values for pthread_mutexattr_{get,set}protocol()
+#define PTHREAD_PRIO_NONE __MLIBC_THREAD_PRIO_NONE
+#define PTHREAD_PRIO_INHERIT __MLIBC_THREAD_PRIO_INHERIT
+#define PTHREAD_PRIO_PROTECT __MLIBC_THREAD_PRIO_PROTECT
+
+#define PTHREAD_ONCE_INIT {0}
+#define PTHREAD_COND_INITIALIZER {0}
+#define PTHREAD_MUTEX_INITIALIZER {0, 0, 0, 0}
+#define PTHREAD_RWLOCK_INITIALIZER {0, 0, 0}
+
+#define PTHREAD_CANCELED ((void*) -1)
+
+#define PTHREAD_BARRIER_SERIAL_THREAD -1
+
+// values for pthread_key
+#define PTHREAD_DESTRUCTOR_ITERATIONS 8
+
+#define PTHREAD_INHERIT_SCHED 0
+#define PTHREAD_EXPLICIT_SCHED 1
+
+#define PTHREAD_STACK_MIN 16384
+
+#define PTHREAD_ATTR_NO_SIGMASK_NP (-1)
+
+// TODO: move to own file and include in sys/types.h
+typedef struct __mlibc_threadattr pthread_attr_t;
+
+typedef uintptr_t pthread_key_t;
+
+struct __mlibc_once {
+	unsigned int __mlibc_done;
+};
+typedef struct __mlibc_once pthread_once_t;
+
+typedef struct __mlibc_mutexattr pthread_mutexattr_t;
+
+typedef struct __mlibc_mutex pthread_mutex_t;
+
+typedef struct __mlibc_condattr pthread_condattr_t;
+
+typedef struct __mlibc_cond pthread_cond_t;
+
+struct  __mlibc_barrierattr_struct {
+	int __mlibc_pshared;
+};
+typedef struct __mlibc_barrierattr_struct pthread_barrierattr_t;
+
+struct __mlibc_barrier {
+	unsigned int __mlibc_waiting;
+	unsigned int __mlibc_inside;
+	unsigned int __mlibc_count;
+	unsigned int __mlibc_seq;
+	unsigned int __mlibc_flags;
+};
+typedef struct __mlibc_barrier pthread_barrier_t;
+
+struct __mlibc_fair_rwlock {
+	unsigned int __mlibc_m; // Mutex.
+	unsigned int __mlibc_rc; // Reader count (not reference count).
+	unsigned int __mlibc_flags;
+};
+typedef struct __mlibc_fair_rwlock pthread_rwlock_t;
+
+struct __mlibc_rwlockattr {
+	int __mlibc_pshared;
+};
+typedef struct __mlibc_rwlockattr pthread_rwlockattr_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+// ----------------------------------------------------------------------------
+// pthread_attr and pthread functions.
+// ----------------------------------------------------------------------------
+
+// pthread_attr functions.
+int pthread_attr_init(pthread_attr_t *);
+int pthread_attr_destroy(pthread_attr_t *);
+
+int pthread_attr_getdetachstate(const pthread_attr_t *, int *);
+int pthread_attr_setdetachstate(pthread_attr_t *, int);
+
+int pthread_attr_getstacksize(const pthread_attr_t *__restrict, size_t *__restrict);
+int pthread_attr_setstacksize(pthread_attr_t *, size_t);
+
+int pthread_attr_getstackaddr(const pthread_attr_t *, void **);
+int pthread_attr_setstackaddr(pthread_attr_t *, void *);
+
+int pthread_attr_getstack(const pthread_attr_t *, void **, size_t*);
+int pthread_attr_setstack(pthread_attr_t *, void *, size_t);
+
+int pthread_attr_getguardsize(const pthread_attr_t *__restrict, size_t *__restrict);
+int pthread_attr_setguardsize(pthread_attr_t *, size_t);
+
+int pthread_attr_getscope(const pthread_attr_t *, int*);
+int pthread_attr_setscope(pthread_attr_t *, int);
+
+int pthread_attr_getschedparam(const pthread_attr_t *__restrict, struct sched_param *__restrict);
+int pthread_attr_setschedparam(pthread_attr_t *__restrict, const struct sched_param *__restrict);
+
+int pthread_attr_getschedpolicy(const pthread_attr_t *__restrict, int *__restrict);
+int pthread_attr_setschedpolicy(pthread_attr_t *__restrict, int);
+
+int pthread_attr_getinheritsched(const pthread_attr_t *__restrict, int *__restrict);
+int pthread_attr_setinheritsched(pthread_attr_t *__restrict, int);
+
+int pthread_attr_getschedparam(const pthread_attr_t *__restrict, struct sched_param *__restrict);
+int pthread_attr_setschedparam(pthread_attr_t *__restrict, const struct sched_param *__restrict);
+
+#if __MLIBC_LINUX_OPTION
+int pthread_attr_getaffinity_np(const pthread_attr_t *__restrict, size_t, cpu_set_t *__restrict);
+int pthread_attr_setaffinity_np(pthread_attr_t *__restrict, size_t, const cpu_set_t *__restrict);
+
+int pthread_attr_getsigmask_np(const pthread_attr_t *__restrict, sigset_t *__restrict);
+int pthread_attr_setsigmask_np(pthread_attr_t *__restrict, const sigset_t *__restrict);
+
+int pthread_getattr_np(pthread_t, pthread_attr_t *);
+
+int pthread_getaffinity_np(pthread_t thread, size_t cpusetsize, cpu_set_t *cpuset);
+int pthread_setaffinity_np(pthread_t thread, size_t cpusetsize, const cpu_set_t *cpuset);
+#endif /* __MLIBC_LINUX_OPTION */
+
+// pthread functions.
+int pthread_create(pthread_t *__restrict, const pthread_attr_t *__restrict,
+		void *(*) (void *), void *__restrict);
+pthread_t pthread_self(void);
+int pthread_equal(pthread_t, pthread_t);
+__attribute__ ((__noreturn__)) void pthread_exit(void *);
+
+int pthread_join(pthread_t, void **);
+int pthread_detach(pthread_t);
+
+void pthread_cleanup_push(void (*) (void *), void *);
+void pthread_cleanup_pop(int);
+
+int pthread_setname_np(pthread_t, const char *);
+int pthread_getname_np(pthread_t, char *, size_t);
+
+int pthread_attr_setstack(pthread_attr_t *, void *, size_t);
+int pthread_attr_getstack(const pthread_attr_t *, void **, size_t *);
+
+int pthread_getattr_np(pthread_t, pthread_attr_t *);
+
+int pthread_setschedparam(pthread_t, int, const struct sched_param *);
+int pthread_getschedparam(pthread_t, int *, struct sched_param *);
+
+int pthread_setcanceltype(int, int *);
+int pthread_setcancelstate(int, int *);
+void pthread_testcancel(void);
+int pthread_cancel(pthread_t);
+
+int pthread_atfork(void (*) (void), void (*) (void), void (*) (void));
+
+// ----------------------------------------------------------------------------
+// pthread_key functions.
+// ----------------------------------------------------------------------------
+
+int pthread_key_create(pthread_key_t *, void (*) (void *));
+int pthread_key_delete(pthread_key_t);
+
+void *pthread_getspecific(pthread_key_t);
+int pthread_setspecific(pthread_key_t, const void *);
+
+// ----------------------------------------------------------------------------
+// pthread_once functions.
+// ----------------------------------------------------------------------------
+
+int pthread_once(pthread_once_t *, void (*) (void));
+
+// ----------------------------------------------------------------------------
+// pthread_mutexattr and pthread_mutex functions.
+// ----------------------------------------------------------------------------
+
+// pthread_mutexattr functions
+int pthread_mutexattr_init(pthread_mutexattr_t *);
+int pthread_mutexattr_destroy(pthread_mutexattr_t *);
+
+int pthread_mutexattr_gettype(const pthread_mutexattr_t *__restrict, int *__restrict);
+int pthread_mutexattr_settype(pthread_mutexattr_t *, int);
+
+int pthread_mutexattr_getrobust(const pthread_mutexattr_t *__restrict, int *__restrict);
+int pthread_mutexattr_setrobust(pthread_mutexattr_t *, int);
+
+int pthread_mutexattr_getpshared(const pthread_mutexattr_t *, int *);
+int pthread_mutexattr_setpshared(pthread_mutexattr_t *, int);
+
+int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *__restrict, int *__restrict);
+int pthread_mutexattr_setprotocol(pthread_mutexattr_t *, int);
+
+int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *, int *);
+int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *, int);
+
+// pthread_mutex functions
+int pthread_mutex_init(pthread_mutex_t *__restrict, const pthread_mutexattr_t *__restrict);
+int pthread_mutex_destroy(pthread_mutex_t *);
+
+int pthread_mutex_lock(pthread_mutex_t *);
+int pthread_mutex_trylock(pthread_mutex_t *);
+int pthread_mutex_timedlock(pthread_mutex_t *__restrict,
+		const struct timespec *__restrict);
+int pthread_mutex_unlock(pthread_mutex_t *);
+
+int pthread_mutex_consistent(pthread_mutex_t *);
+
+// ----------------------------------------------------------------------------
+// pthread_condattr and pthread_cond functions.
+// ----------------------------------------------------------------------------
+
+int pthread_condattr_init(pthread_condattr_t *);
+int pthread_condattr_destroy(pthread_condattr_t *);
+
+int pthread_condattr_getclock(const pthread_condattr_t *__restrict, clockid_t *__restrict);
+int pthread_condattr_setclock(pthread_condattr_t *, clockid_t);
+
+int pthread_condattr_getpshared(const pthread_condattr_t *__restrict, int *__restrict);
+int pthread_condattr_setpshared(pthread_condattr_t *, int);
+
+int pthread_cond_init(pthread_cond_t *__restrict, const pthread_condattr_t *__restrict);
+int pthread_cond_destroy(pthread_cond_t *);
+
+int pthread_cond_wait(pthread_cond_t *__restrict, pthread_mutex_t *__restrict);
+int pthread_cond_timedwait(pthread_cond_t *__restrict, pthread_mutex_t *__restrict,
+		const struct timespec *__restrict);
+int pthread_cond_signal(pthread_cond_t *);
+int pthread_cond_broadcast(pthread_cond_t *);
+
+// ----------------------------------------------------------------------------
+// pthread_barrierattr and pthread_barrier functions.
+// ----------------------------------------------------------------------------
+
+int pthread_barrierattr_init(pthread_barrierattr_t *);
+int pthread_barrierattr_destroy(pthread_barrierattr_t *);
+int pthread_barrierattr_setpshared(pthread_barrierattr_t *, int);
+int pthread_barrierattr_getpshared(const pthread_barrierattr_t *__restrict,
+		int *__restrict);
+
+int pthread_barrier_init(pthread_barrier_t *__restrict, const pthread_barrierattr_t *__restrict,
+		unsigned int);
+int pthread_barrier_destroy(pthread_barrier_t *);
+
+int pthread_barrier_wait(pthread_barrier_t *);
+
+// ----------------------------------------------------------------------------
+// pthread_wrlockattr and pthread_rwlock functions.
+// ----------------------------------------------------------------------------
+
+int pthread_rwlockattr_init(pthread_rwlockattr_t *);
+int pthread_rwlockattr_destroy(pthread_rwlockattr_t *);
+int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *, int);
+int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *__restrict,
+		int *__restrict);
+
+int pthread_rwlock_init(pthread_rwlock_t *__restrict, const pthread_rwlockattr_t *__restrict);
+int pthread_rwlock_destroy(pthread_rwlock_t *);
+int pthread_rwlock_trywrlock(pthread_rwlock_t *);
+int pthread_rwlock_wrlock(pthread_rwlock_t *);
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *);
+int pthread_rwlock_rdlock(pthread_rwlock_t *);
+int pthread_rwlock_unlock(pthread_rwlock_t *);
+
+int pthread_getcpuclockid(pthread_t, clockid_t *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _PTHREAD_H
+
diff --git a/lib/mlibc/options/posix/include/pwd.h b/lib/mlibc/options/posix/include/pwd.h
new file mode 100644
index 0000000..b885f57
--- /dev/null
+++ b/lib/mlibc/options/posix/include/pwd.h
@@ -0,0 +1,45 @@
+
+#ifndef _PWD_H
+#define _PWD_H
+
+#include <abi-bits/uid_t.h>
+#include <abi-bits/gid_t.h>
+#include <bits/size_t.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct passwd {
+	char *pw_name;
+	char *pw_passwd;
+	uid_t pw_uid;
+	gid_t pw_gid;
+	char *pw_gecos;
+	char *pw_dir;
+	char *pw_shell;
+};
+
+#define NSS_BUFLEN_PASSWD 512
+
+#ifndef __MLIBC_ABI_ONLY
+
+void endpwent(void);
+struct passwd *getpwent(void);
+struct passwd *getpwnam(const char *);
+int getpwnam_r(const char *, struct passwd *, char *, size_t, struct passwd **);
+struct passwd *getpwuid(uid_t);
+int getpwuid_r(uid_t, struct passwd *, char *, size_t, struct passwd **);
+void setpwent(void);
+int putpwent(const struct passwd *, FILE *);
+struct passwd *fgetpwent(FILE *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _PWD_H
+
diff --git a/lib/mlibc/options/posix/include/regex.h b/lib/mlibc/options/posix/include/regex.h
new file mode 100644
index 0000000..b7f0a46
--- /dev/null
+++ b/lib/mlibc/options/posix/include/regex.h
@@ -0,0 +1,66 @@
+#ifndef _REGEX_H
+#define _REGEX_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+
+typedef ptrdiff_t regoff_t;
+
+typedef struct re_pattern_buffer {
+	size_t re_nsub;
+	void *__opaque, *__padding[4];
+	size_t __nsub2;
+	char __padding2;
+} regex_t;
+
+typedef struct {
+	regoff_t rm_so;
+	regoff_t rm_eo;
+} regmatch_t;
+
+// Flags for regcomp().
+#define REG_EXTENDED 1
+#define REG_ICASE 2
+#define REG_NEWLINE 4
+#define REG_NOSUB 8
+
+// Flags for regexec().
+#define REG_NOTBOL 1
+#define REG_NOTEOL 2
+
+// Errors for regcomp() and regexec().
+#define REG_OK 0
+#define REG_NOMATCH 1
+#define REG_BADPAT 2
+#define REG_ECOLLATE 3
+#define REG_ECTYPE 4
+#define REG_EESCAPE 5
+#define REG_ESUBREG 6
+#define REG_EBRACK 7
+#define REG_EPAREN 8
+#define REG_EBRACE 9
+#define REG_BADBR 10
+#define REG_ERANGE 11
+#define REG_ESPACE 12
+#define REG_BADRPT 13
+
+// Obsolete in POSIX.
+#define REG_ENOSYS -1
+
+#ifndef __MLIBC_ABI_ONLY
+
+int regcomp(regex_t *__restrict, const char *__restrict, int);
+int regexec(const regex_t *__restrict, const char *__restrict, size_t, regmatch_t *__restrict, int);
+size_t regerror(int, const regex_t *__restrict, char *__restrict, size_t);
+void regfree(regex_t *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib/mlibc/options/posix/include/sched.h b/lib/mlibc/options/posix/include/sched.h
new file mode 100644
index 0000000..739d91e
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sched.h
@@ -0,0 +1,49 @@
+
+#ifndef _SCHED_H
+#define _SCHED_H
+
+#include <abi-bits/pid_t.h>
+#include <bits/threads.h>
+#include <bits/size_t.h>
+#include <mlibc-config.h>
+
+// MISSING: time_t, struct timespec
+
+// MISSING: POSIX [PS], [SS] and [TSP] options
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if __MLIBC_LINUX_OPTION
+#include <bits/linux/linux_sched.h>
+#include <bits/linux/cpu_set.h>
+#endif
+
+#define SCHED_OTHER 0
+#define SCHED_FIFO 1
+#define SCHED_RR 2
+#define SCHED_BATCH 3
+#define SCHED_IDLE 5
+#define SCHED_DEADLINE 6
+#define SCHED_RESET_ON_FORK 0x40000000
+
+#ifndef __MLIBC_ABI_ONLY
+
+int sched_yield(void);
+
+int sched_get_priority_max(int policy);
+int sched_get_priority_min(int policy);
+
+int sched_setscheduler(pid_t pid, int policy, const struct sched_param *param);
+
+int sched_getparam(pid_t pid, struct sched_param *param);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SCHED_H
+
diff --git a/lib/mlibc/options/posix/include/search.h b/lib/mlibc/options/posix/include/search.h
new file mode 100644
index 0000000..02e1913
--- /dev/null
+++ b/lib/mlibc/options/posix/include/search.h
@@ -0,0 +1,37 @@
+
+#ifndef _SEARCH_H
+#define _SEARCH_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+  preorder,
+  postorder,
+  endorder,
+  leaf
+} VISIT;
+
+#ifndef __MLIBC_ABI_ONLY
+
+void *tsearch(const void *, void **, int(*compar)(const void *, const void *));
+void *tfind(const void *, void *const *, int (*compar)(const void *, const void *));
+void *tdelete(const void *, void **, int(*compar)(const void *, const void *));
+void twalk(const void *, void (*action)(const void *, VISIT, int));
+void tdestroy(void *, void (*free_node)(void *));
+
+void *lsearch(const void *key, void *base, size_t *nelp, size_t width,
+		int (*compar)(const void *, const void *));
+void *lfind(const void *key, const void *base, size_t *nelp,
+		size_t width, int (*compar)(const void *, const void *));
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SEARCH_H
diff --git a/lib/mlibc/options/posix/include/semaphore.h b/lib/mlibc/options/posix/include/semaphore.h
new file mode 100644
index 0000000..877527f
--- /dev/null
+++ b/lib/mlibc/options/posix/include/semaphore.h
@@ -0,0 +1,37 @@
+#ifndef _SEMAPHORE_H
+#define _SEMAPHORE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/ansi/time_t.h>
+#include <bits/ansi/timespec.h>
+
+#define SEM_VALUE_MAX 0x7FFFFFFF
+#define SEM_FAILED ((sem_t *) 0)
+
+typedef struct sem_ {
+	unsigned int __mlibc_count;
+} sem_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+int sem_init(sem_t *sem, int pshared, unsigned int initial_count);
+sem_t *sem_open(const char *, int, ...);
+int sem_close(sem_t *sem);
+int sem_unlink(const char *);
+int sem_destroy(sem_t *sem);
+int sem_wait(sem_t *sem);
+int sem_trywait(sem_t *sem);
+int sem_timedwait(sem_t *sem, const struct timespec *abstime);
+int sem_post(sem_t *sem);
+int sem_getvalue(sem_t *sem, int *sval);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif //_SEMAPHORE_H
diff --git a/lib/mlibc/options/posix/include/spawn.h b/lib/mlibc/options/posix/include/spawn.h
new file mode 100644
index 0000000..3ab2004
--- /dev/null
+++ b/lib/mlibc/options/posix/include/spawn.h
@@ -0,0 +1,82 @@
+
+#ifndef _SPAWN_H
+#define _SPAWN_H
+
+#include <abi-bits/signal.h>
+#include <abi-bits/mode_t.h>
+#include <abi-bits/pid_t.h>
+#include <sched.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+	int __flags;
+	pid_t __pgrp;
+	sigset_t __def, __mask;
+	int __prio, __pol;
+	void *__fn;
+	char __pad[64 - sizeof(void *)];
+} posix_spawnattr_t;
+
+typedef struct {
+	int __pad0[2];
+	void *__actions;
+	int __pad[16];
+} posix_spawn_file_actions_t;
+
+// MISSIG: sigset_t
+
+struct sched_param;
+
+#define POSIX_SPAWN_RESETIDS 1
+#define POSIX_SPAWN_SETPGROUP 2
+#define POSIX_SPAWN_SETSIGDEF 4
+#define POSIX_SPAWN_SETSIGMASK 8
+#define POSIX_SPAWN_SETSCHEDPARAM 16
+#define POSIX_SPAWN_SETSCHEDULER 32
+#define POSIX_SPAWN_USEVFORK 64
+#define POSIX_SPAWN_SETSID 128
+
+#ifndef __MLIBC_ABI_ONLY
+
+int posix_spawn(pid_t *__restrict pid, const char *__restrict path,
+		const posix_spawn_file_actions_t *file_actions,
+		const posix_spawnattr_t *__restrict attrs,
+		char *const argv[], char *const envp[]);
+
+int posix_spawnattr_init(posix_spawnattr_t *attr);
+int posix_spawnattr_destroy(posix_spawnattr_t *attr);
+int posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags);
+int posix_spawnattr_setsigdefault(posix_spawnattr_t *__restrict attr,
+		const sigset_t *__restrict sigdefault);
+int posix_spawnattr_setschedparam(posix_spawnattr_t *__restrict attr,
+		const struct sched_param *__restrict schedparam);
+int posix_spawnattr_setschedpolicy(posix_spawnattr_t *attr, int schedpolicy);
+int posix_spawnattr_setsigmask(posix_spawnattr_t *__restrict attr,
+		const sigset_t *__restrict sigmask);
+int posix_spawnattr_setpgroup(posix_spawnattr_t *attr, pid_t pgroup);
+int posix_spawn_file_actions_init(posix_spawn_file_actions_t *file_actions);
+int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *file_actions);
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions,
+		int fildes, int newfildes);
+int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
+		int fildes);
+int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *__restrict file_actions,
+		int fildes, const char *__restrict path, int oflag, mode_t mode);
+int posix_spawnp(pid_t *__restrict pid, const char *__restrict file,
+		const posix_spawn_file_actions_t *file_actions,
+		const posix_spawnattr_t *__restrict attrp,
+		char *const argv[], char *const envp[]);
+
+// MISSING: all other functions
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // SPAWN_H
+
diff --git a/lib/mlibc/options/posix/include/strings.h b/lib/mlibc/options/posix/include/strings.h
new file mode 100644
index 0000000..a21c3d7
--- /dev/null
+++ b/lib/mlibc/options/posix/include/strings.h
@@ -0,0 +1,32 @@
+
+#ifndef _STRINGS_H
+#define _STRINGS_H
+
+#include <bits/size_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+char *index (const char *s, int c);
+char *rindex(const char *s, int c);
+
+int ffs(int word);
+int strcasecmp(const char *a, const char *b);
+int strncasecmp(const char *a, const char *b, size_t size);
+
+/* Marked as obsolete in posix 2008 but used by at least tracker */
+int bcmp(const void *s1, const void *s2, size_t n);
+void bcopy(const void *s1, void *s2, size_t n);
+void bzero(void *s, size_t n);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _STRINGS_H
+
diff --git a/lib/mlibc/options/posix/include/sys/file.h b/lib/mlibc/options/posix/include/sys/file.h
new file mode 100644
index 0000000..add43d3
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/file.h
@@ -0,0 +1,25 @@
+
+#ifndef _SYS_FILE_H
+#define _SYS_FILE_H
+
+#define LOCK_SH 1
+#define LOCK_EX 2
+#define LOCK_NB 4
+#define LOCK_UN 8
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int flock(int, int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_FILE_H
+
diff --git a/lib/mlibc/options/posix/include/sys/ipc.h b/lib/mlibc/options/posix/include/sys/ipc.h
new file mode 100644
index 0000000..8318dde
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/ipc.h
@@ -0,0 +1,53 @@
+#ifndef _SYS_IPC_H
+#define _SYS_IPC_H
+
+#include <abi-bits/uid_t.h>
+#include <abi-bits/gid_t.h>
+#include <abi-bits/mode_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define IPC_CREAT 01000
+#define IPC_EXCL 02000
+#define IPC_NOWAIT 04000
+
+#define IPC_RMID 0
+#define IPC_SET 1
+#define IPC_STAT 2
+#define IPC_INFO 3
+
+#define IPC_PRIVATE ((key_t) 0)
+
+#if defined(__aarch64__) || defined(__i386__)
+#define IPC_64 0x100
+#elif defined(__x86_64__) || (defined(__riscv) && __riscv_xlen == 64)
+#define IPC_64 0
+#else
+#error "Unsupported arch!"
+#endif
+
+typedef int key_t;
+
+struct ipc_perm {
+	key_t __ipc_perm_key;
+	uid_t uid;
+	gid_t gid;
+	uid_t cuid;
+	gid_t cgid;
+	mode_t mode;
+	int __ipc_perm_seq;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+key_t ftok(const char *, int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib/mlibc/options/posix/include/sys/mman.h b/lib/mlibc/options/posix/include/sys/mman.h
new file mode 100644
index 0000000..784878e
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/mman.h
@@ -0,0 +1,47 @@
+#ifndef _SYS_MMAN_H
+#define _SYS_MMAN_H
+
+#include <mlibc-config.h>
+#include <abi-bits/mode_t.h>
+#include <abi-bits/vm-flags.h>
+#include <bits/off_t.h>
+#include <bits/size_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+void *mmap(void *, size_t, int, int, int, off_t);
+int mprotect(void *, size_t, int);
+int munmap(void *, size_t);
+
+int mlock(const void *, size_t);
+int mlockall(int);
+int munlock(const void *, size_t);
+int munlockall(void);
+
+int posix_madvise(void *, size_t, int);
+int msync(void *, size_t, int);
+
+int shm_open(const char *, int, mode_t);
+int shm_unlink(const char *);
+
+// Linux extension:
+void *mremap(void *, size_t, size_t, int, ...);
+int remap_file_pages(void *, size_t, int, size_t, int);
+
+#if __MLIBC_LINUX_OPTION
+int memfd_create(const char *, unsigned int);
+int madvise(void *, size_t, int);
+int mincore(void *, size_t, unsigned char *);
+#endif /* __MLIBC_LINUX_OPTION */
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_MMAN_H
diff --git a/lib/mlibc/options/posix/include/sys/msg.h b/lib/mlibc/options/posix/include/sys/msg.h
new file mode 100644
index 0000000..d602f76
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/msg.h
@@ -0,0 +1,27 @@
+#ifndef _SYS_MSG_H
+#define _SYS_MSG_H
+
+#include <abi-bits/msg.h>
+#include <bits/size_t.h>
+#include <bits/ssize_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int msgget(key_t, int);
+
+int msgctl(int msqid, int cmd, struct msqid_ds *buf);
+
+ssize_t msgrcv(int, void *, size_t, long, int);
+int msgsnd(int, const void *, size_t, int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_MSG_H
diff --git a/lib/mlibc/options/posix/include/sys/param.h b/lib/mlibc/options/posix/include/sys/param.h
new file mode 100644
index 0000000..9bb4552
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/param.h
@@ -0,0 +1,36 @@
+
+#ifndef _SYS_PARAM_H
+#define _SYS_PARAM_H
+
+#include <endian.h>
+#include <limits.h>
+
+#define NBBY CHAR_BIT
+#define NGROUPS NGROUPS_MAX
+
+// Report the same value as Linux here.
+#define MAXNAMLEN 255
+#define MAXPATHLEN 4096
+#define HOST_NAME_MAX 64
+#define MAXSYMLINKS 20
+#define MAXHOSTNAMELEN HOST_NAME_MAX
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#undef MIN
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#undef MAX
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+
+#define howmany(x, y)  (((x) + ((y) - 1)) / (y))
+
+#define roundup(x, y)  ((((x) + ((y) - 1)) / (y)) * (y))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_PARAM_H
+
diff --git a/lib/mlibc/options/posix/include/sys/poll.h b/lib/mlibc/options/posix/include/sys/poll.h
new file mode 100644
index 0000000..3edecab
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/poll.h
@@ -0,0 +1,37 @@
+#ifndef _SYS_POLL_H
+#define _SYS_POLL_H
+
+#include <bits/types.h>
+#include <bits/sigset_t.h>
+#include <bits/ansi/timespec.h>
+#include <abi-bits/poll.h>
+#include <abi-bits/signal.h>
+#include <mlibc-config.h>
+
+typedef __mlibc_size nfds_t;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct pollfd {
+	int fd;
+	short events;
+	short revents;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int poll(struct pollfd *, nfds_t, int);
+
+#if __MLIBC_LINUX_OPTION
+int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *timeout_ts, const sigset_t *sigmask);
+#endif // __MLIBC_LINUX_OPTION
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_POLL_H
diff --git a/lib/mlibc/options/posix/include/sys/resource.h b/lib/mlibc/options/posix/include/sys/resource.h
new file mode 100644
index 0000000..c5453e2
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/resource.h
@@ -0,0 +1,52 @@
+#ifndef _SYS_RESOURCE_H
+#define _SYS_RESOURCE_H
+
+#include <abi-bits/pid_t.h>
+#include <abi-bits/resource.h>
+#include <bits/posix/id_t.h>
+#include <abi-bits/suseconds_t.h>
+#include <bits/ansi/time_t.h>
+#include <bits/posix/timeval.h>
+
+#define PRIO_PROCESS 1
+#define PRIO_PGRP 2
+#define PRIO_USER 3
+
+#define PRIO_MIN (-20)
+#define PRIO_MAX 20
+
+#define RLIM_INFINITY ((rlim_t)-1)
+#define RLIM_SAVED_MAX ((rlim_t)-1)
+#define RLIM_SAVED_CUR ((rlim_t)-1)
+
+#define RLIM_NLIMITS RLIMIT_NLIMITS
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef unsigned long rlim_t;
+
+struct rlimit {
+	rlim_t rlim_cur;
+	rlim_t rlim_max;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int getpriority(int, id_t);
+int setpriority(int, id_t, int);
+
+int getrusage(int, struct rusage *);
+int getrlimit(int, struct rlimit *);
+int setrlimit(int, const struct rlimit *);
+
+int prlimit(pid_t pid, int resource, const struct rlimit *new_limits, struct rlimit *old_limits);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_RESOURCE_H
diff --git a/lib/mlibc/options/posix/include/sys/select.h b/lib/mlibc/options/posix/include/sys/select.h
new file mode 100644
index 0000000..85a15b0
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/select.h
@@ -0,0 +1,49 @@
+
+#ifndef _SYS_SELECT_H
+#define _SYS_SELECT_H
+
+#include <abi-bits/signal.h>
+
+#include <bits/ansi/time_t.h>
+#include <bits/ansi/timespec.h>
+#include <abi-bits/suseconds_t.h>
+#include <bits/posix/timeval.h>
+#include <bits/posix/fd_set.h>
+
+#define FD_SETSIZE 1024
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef long int __fd_mask;
+#define __NFDBITS (8 * (int) sizeof (__fd_mask))
+
+typedef __fd_mask fd_mask;
+#define NFDBITS __NFDBITS
+
+#ifndef __MLIBC_ABI_ONLY
+
+void __FD_CLR(int fd, fd_set *);
+int __FD_ISSET(int fd, fd_set *);
+void __FD_SET(int fd, fd_set *);
+void __FD_ZERO(fd_set *);
+
+#define FD_CLR(fd, set) __FD_CLR(fd, set)
+#define FD_ISSET(fd, set) __FD_ISSET(fd, set)
+#define FD_SET(fd, set) __FD_SET(fd, set)
+#define FD_ZERO(set) __FD_ZERO(set)
+
+int select(int, fd_set *__restrict, fd_set *__restrict, fd_set *__restrict,
+		struct timeval *__restrict);
+int pselect(int, fd_set *, fd_set *, fd_set *, const struct timespec *,
+		const sigset_t *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_SELECT_H
+
diff --git a/lib/mlibc/options/posix/include/sys/sem.h b/lib/mlibc/options/posix/include/sys/sem.h
new file mode 100644
index 0000000..cb3516a
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/sem.h
@@ -0,0 +1,44 @@
+#ifndef _SYS_SEM_H
+#define _SYS_SEM_H
+
+#include <bits/ansi/time_t.h>
+#include <sys/ipc.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GETALL 13
+#define SETVAL 16
+#define SETALL 17
+
+#define SEM_UNDO 0x1000
+
+struct sembuf {
+	unsigned short int sem_num;
+	short int sem_op;
+	short int sem_flg;
+};
+
+struct semid_ds {
+	struct ipc_perm sem_perm;
+	time_t          sem_otime;
+	time_t          sem_ctime;
+
+	unsigned long   sem_nsems;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int semget(key_t, int, int);
+int semop(int, struct sembuf *, size_t);
+int semctl(int, int, int, ...);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_SEM_H
diff --git a/lib/mlibc/options/posix/include/sys/shm.h b/lib/mlibc/options/posix/include/sys/shm.h
new file mode 100644
index 0000000..3767ced
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/shm.h
@@ -0,0 +1,83 @@
+#ifndef _SYS_SHM_H
+#define _SYS_SHM_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <abi-bits/pid_t.h>
+#include <abi-bits/shm.h>
+#include <bits/size_t.h>
+#include <time.h>
+
+#include <sys/ipc.h>
+
+#define SHM_R 0400
+#define SHM_W 0200
+
+#define SHM_RDONLY 010000
+#define SHM_RND 020000
+#define SHM_REMAP 040000
+#define SHM_EXEC 0100000
+
+#define SHM_LOCK 11
+#define SHM_UNLOCK 12
+#define SHM_STAT 13
+#define SHM_INFO 14
+#define SHM_STAT_ANY 15
+#define SHM_DEST 01000
+#define SHM_LOCKED 02000
+#define SHM_HUGETLB 04000
+#define SHM_NORESERVE 010000
+
+#define SHM_HUGE_SHIFT 26
+#define SHM_HUGE_MASK 0x3f
+#define SHM_HUGE_64KB (16 << 26)
+#define SHM_HUGE_512KB (19 << 26)
+#define SHM_HUGE_1MB (20 << 26)
+#define SHM_HUGE_2MB (21 << 26)
+#define SHM_HUGE_8MB (23 << 26)
+#define SHM_HUGE_16MB (24 << 26)
+#define SHM_HUGE_32MB (25 << 26)
+#define SHM_HUGE_256MB (28 << 26)
+#define SHM_HUGE_512MB (29 << 26)
+#define SHM_HUGE_1GB (30 << 26)
+#define SHM_HUGE_2GB (31 << 26)
+#define SHM_HUGE_16GB (34U << 26)
+
+typedef unsigned long shmatt_t;
+
+struct shmid_ds {
+	struct ipc_perm shm_perm;
+	size_t shm_segsz;
+	time_t shm_atime;
+	time_t shm_dtime;
+	time_t shm_ctime;
+	pid_t shm_cpid;
+	pid_t shm_lpid;
+	unsigned long shm_nattch;
+};
+
+struct shminfo {
+	unsigned long shmmax;
+	unsigned long shmmin;
+	unsigned long shmmni;
+	unsigned long shmseg;
+	unsigned long shmall;
+	unsigned long __unused[4];
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+void *shmat(int, const void *, int);
+int shmctl(int, int, struct shmid_ds *);
+int shmdt(const void *);
+int shmget(key_t, size_t, int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_SHM_H
diff --git a/lib/mlibc/options/posix/include/sys/socket.h b/lib/mlibc/options/posix/include/sys/socket.h
new file mode 100644
index 0000000..9552f93
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/socket.h
@@ -0,0 +1,105 @@
+
+#ifndef _SOCKET_H
+#define _SOCKET_H
+
+#include <abi-bits/gid_t.h>
+#include <abi-bits/pid_t.h>
+#include <bits/size_t.h>
+#include <abi-bits/socklen_t.h>
+#include <bits/ssize_t.h>
+#include <abi-bits/uid_t.h>
+#include <bits/posix/iovec.h>
+#include <abi-bits/socket.h>
+#include <bits/ansi/time_t.h>
+#include <bits/ansi/timespec.h>
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct sockaddr {
+	sa_family_t sa_family;
+	char sa_data[14];
+};
+
+// Control message format:
+// The offsets marked with ^ are aligned to alignof(size_t).
+//
+// |---HEADER---|---DATA---|---PADDING---|---HEADER---|...
+// ^            ^                        ^
+// |---------CMSG_LEN------|
+// |---------------CMSG_SPACE------------|
+
+// Auxiliary macro. While there is basically no reason for applications
+// to use this, it is exported by glibc.
+#define CMSG_ALIGN(s) (((s) + __alignof__(size_t) - 1) & \
+		~(__alignof__(size_t) - 1))
+
+// Basic macros to return content and padding size of a control message.
+#define CMSG_LEN(s) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (s))
+#define CMSG_SPACE(s) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(s))
+
+// Provides access to the data of a control message.
+#define CMSG_DATA(c) ((char *)(c) + CMSG_ALIGN(sizeof(struct cmsghdr)))
+
+#define __MLIBC_CMSG_NEXT(c) ((char *)(c) + CMSG_ALIGN((c)->cmsg_len))
+#define __MLIBC_MHDR_LIMIT(m) ((char *)(m)->msg_control + (m)->msg_controllen)
+
+// For parsing control messages only.
+// Returns a pointer to the first header or nullptr if there is none.
+#define CMSG_FIRSTHDR(m) ((size_t)(m)->msg_controllen <= sizeof(struct cmsghdr) \
+	? (struct cmsghdr *)0 : (struct cmsghdr *) (m)->msg_control)
+
+// For parsing control messages only.
+// Returns a pointer to the next header or nullptr if there is none.
+#define CMSG_NXTHDR(m, c) \
+	((c)->cmsg_len < sizeof(struct cmsghdr) || \
+		(ptrdiff_t)(sizeof(struct cmsghdr) + CMSG_ALIGN((c)->cmsg_len)) \
+			>= __MLIBC_MHDR_LIMIT(m) - (char *)(c) \
+	? (struct cmsghdr *)0 : (struct cmsghdr *)__MLIBC_CMSG_NEXT(c))
+
+struct linger{
+	int l_onoff;
+	int l_linger;
+};
+
+struct ucred {
+	pid_t pid;
+	uid_t uid;
+	gid_t gid;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int accept(int, struct sockaddr *__restrict, socklen_t *__restrict);
+int accept4(int, struct sockaddr *__restrict, socklen_t *__restrict, int);
+int bind(int, const struct sockaddr *, socklen_t);
+int connect(int, const struct sockaddr *, socklen_t);
+int getpeername(int, struct sockaddr *__restrict, socklen_t *__restrict);
+int getsockname(int, struct sockaddr *__restrict, socklen_t *__restrict);
+int getsockopt(int, int, int, void *__restrict, socklen_t *__restrict);
+int listen(int, int);
+ssize_t recv(int, void *, size_t, int);
+ssize_t recvfrom(int, void *__restrict, size_t, int, struct sockaddr *__restrict, socklen_t *__restrict);
+ssize_t recvmsg(int, struct msghdr *, int);
+ssize_t send(int, const void *, size_t, int);
+ssize_t sendmsg(int, const struct msghdr *, int);
+ssize_t sendto(int, const void *, size_t, int, const struct sockaddr *, socklen_t);
+int recvmmsg(int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags, struct timespec *timeout);
+int sendmmsg(int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags);
+int setsockopt(int, int, int, const void *, socklen_t);
+int shutdown(int, int);
+int sockatmark(int);
+int socket(int, int, int);
+int socketpair(int, int, int, int [2]);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _UNISTD_H
+
diff --git a/lib/mlibc/options/posix/include/sys/stat.h b/lib/mlibc/options/posix/include/sys/stat.h
new file mode 100644
index 0000000..7159a77
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/stat.h
@@ -0,0 +1,37 @@
+
+#ifndef _SYS_STAT_H
+#define _SYS_STAT_H
+
+#include <bits/posix/stat.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int chmod(const char *, mode_t);
+int fchmod(int, mode_t);
+int fchmodat(int, const char *, mode_t, int);
+int fstat(int fd, struct stat *result);
+int fstatat(int, const char *__restrict, struct stat *__restrict, int);
+int futimens(int fd, const struct timespec times[2]);
+int lstat(const char *__restrict, struct stat *__restrict);
+int mkdir(const char *, mode_t);
+int mkdirat(int, const char *, mode_t);
+int mkfifo(const char *, mode_t);
+int mkfifoat(int, const char *, mode_t);
+int mknod(const char *, mode_t, dev_t);
+int mknodat(int, const char *, mode_t, dev_t);
+int stat(const char *__restrict, struct stat *__restrict);
+mode_t umask(mode_t);
+int utimensat(int, const char *, const struct timespec times[2], int);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_STAT_H
+
diff --git a/lib/mlibc/options/posix/include/sys/statvfs.h b/lib/mlibc/options/posix/include/sys/statvfs.h
new file mode 100644
index 0000000..0e4c308
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/statvfs.h
@@ -0,0 +1,22 @@
+#ifndef _SYS_STATVFS_H
+#define _SYS_STATVFS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <abi-bits/statvfs.h>
+
+#ifndef __MLIBC_ABI_ONLY
+
+int statvfs(const char *__restrict, struct statvfs *__restrict);
+int fstatvfs(int, struct statvfs *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_STATVFS_H
+
diff --git a/lib/mlibc/options/posix/include/sys/syslog.h b/lib/mlibc/options/posix/include/sys/syslog.h
new file mode 100644
index 0000000..7761ece
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/syslog.h
@@ -0,0 +1 @@
+#include <syslog.h>
diff --git a/lib/mlibc/options/posix/include/sys/termios.h b/lib/mlibc/options/posix/include/sys/termios.h
new file mode 100644
index 0000000..b23f171
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/termios.h
@@ -0,0 +1,6 @@
+
+#ifndef _SYS_TERMIOS_H
+#define _SYS_TERMIOS_H
+#include <termios.h>
+#endif // _SYS_TERMIOS_H
+
diff --git a/lib/mlibc/options/posix/include/sys/time.h b/lib/mlibc/options/posix/include/sys/time.h
new file mode 100644
index 0000000..838d7cc
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/time.h
@@ -0,0 +1,68 @@
+#ifndef _SYS_TIME_H
+#define _SYS_TIME_H
+
+#include <abi-bits/time.h>
+#include <abi-bits/signal.h>
+#include <abi-bits/clockid_t.h>
+#include <bits/ansi/time_t.h>
+#include <abi-bits/suseconds_t.h>
+#include <bits/posix/timer_t.h>
+#include <bits/posix/timeval.h>
+
+#include <sys/select.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct timezone {
+	int tz_minuteswest;
+	int tz_dsttime;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+// TODO: this function is [OB]. disable it by default and add a macro to enable it
+int gettimeofday(struct timeval *__restrict result, void *__restrict unused);
+int settimeofday(const struct timeval *result, const struct timezone *zone);
+
+void timeradd(const struct timeval *a, const struct timeval *b, struct timeval *res);
+void timersub(const struct timeval *a, const struct timeval *b, struct timeval *res);
+void timerclear(struct timeval *tvp);
+int timerisset(struct timeval *tvp);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+// timercmp taken from musl
+#define timercmp(s,t,op) ((s)->tv_sec == (t)->tv_sec ? \
+	(s)->tv_usec op (t)->tv_usec : (s)->tv_sec op (t)->tv_sec)
+
+#ifndef __MLIBC_ABI_ONLY
+
+int getitimer(int which, struct itimerval *curr_value);
+int setitimer(int which, const struct itimerval *new_value,
+	struct itimerval *old_value);
+
+int timer_create(clockid_t clockid, struct sigevent *__restrict sevp, timer_t *__restrict timerid);
+int timer_settime(timer_t timerid, int flags, const struct itimerspec *__restrict new_value,
+	struct itimerspec *__restrict old_value);
+int timer_gettime(timer_t timerid, struct itimerspec *curr_value);
+int timer_delete(timer_t timerid);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+// The following 2 macros are taken from musl
+#define TIMEVAL_TO_TIMESPEC(tv, ts) ( \
+	(ts)->tv_sec = (tv)->tv_sec, \
+	(ts)->tv_nsec = (tv)->tv_usec * 1000, \
+	(void)0 )
+#define TIMESPEC_TO_TIMEVAL(tv, ts) ( \
+	(tv)->tv_sec = (ts)->tv_sec, \
+	(tv)->tv_usec = (ts)->tv_nsec / 1000, \
+	(void)0 )
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_TIME_H
diff --git a/lib/mlibc/options/posix/include/sys/times.h b/lib/mlibc/options/posix/include/sys/times.h
new file mode 100644
index 0000000..2dd2889
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/times.h
@@ -0,0 +1,28 @@
+#ifndef _SYS_TIMES_H
+#define _SYS_TIMES_H
+
+// TODO: Only define the clock_t type.
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct tms {
+	clock_t tms_utime;
+	clock_t tms_stime;
+	clock_t tms_cutime;
+	clock_t tms_cstime;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+clock_t times(struct tms *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_TIMES_H
diff --git a/lib/mlibc/options/posix/include/sys/ttydefaults.h b/lib/mlibc/options/posix/include/sys/ttydefaults.h
new file mode 100644
index 0000000..c6d04f6
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/ttydefaults.h
@@ -0,0 +1,39 @@
+
+#ifndef _SYS_TTYDEFAULTS_H
+#define _SYS_TTYDEFAULTS_H
+
+// Values taken from musl
+
+#define TTYDEF_IFLAG (BRKINT | ISTRIP | ICRNL | IMAXBEL | IXON | IXANY)
+#define TTYDEF_OFLAG (OPOST | ONLCR | XTABS)
+#define TTYDEF_LFLAG (ECHO | ICANON | ISIG | IEXTEN | ECHOE|ECHOKE|ECHOCTL)
+#define TTYDEF_CFLAG (CREAD | CS7 | PARENB | HUPCL)
+#define TTYDEF_SPEED (B9600)
+
+#define CTRL(x) ((x) & 037)
+#define CEOF CTRL('d')
+
+#define CEOL '\0'
+#define CEOL2 '\0'
+#define CSTATUS '\0'
+
+#define CERASE 0177
+#define CINTR CTRL('c')
+#define CKILL CTRL('u')
+#define CMIN 1
+#define CQUIT 034
+#define CSUSP CTRL('z')
+#define CTIME 0
+#define CDSUSP CTRL('y')
+#define CSTART CTRL('q')
+#define CSTOP CTRL('s')
+#define CLNEXT CTRL('v')
+#define CDISCARD CTRL('o')
+#define CWERASE CTRL('w')
+#define CREPRINT CTRL('r')
+#define CEOT CEOF
+#define CBRK CEOL
+#define CRPRNT CREPRINT
+#define CFLUSH CDISCARD
+
+#endif // _SYS_TTYDEFAULTS_H
diff --git a/lib/mlibc/options/posix/include/sys/types.h b/lib/mlibc/options/posix/include/sys/types.h
new file mode 100644
index 0000000..ad837fc
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/types.h
@@ -0,0 +1,53 @@
+
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+
+#include <bits/size_t.h>
+#include <bits/ssize_t.h>
+#include <bits/off_t.h>
+
+#include <bits/posix/id_t.h>
+#include <abi-bits/uid_t.h>
+#include <abi-bits/gid_t.h>
+#include <abi-bits/pid_t.h>
+
+#include <abi-bits/mode_t.h>
+#include <abi-bits/dev_t.h>
+#include <abi-bits/ino_t.h>
+#include <abi-bits/blksize_t.h>
+#include <abi-bits/blkcnt_t.h>
+#include <abi-bits/nlink_t.h>
+
+#include <bits/ansi/time_t.h>
+#include <abi-bits/suseconds_t.h>
+
+#include <abi-bits/fsblkcnt_t.h>
+#include <abi-bits/fsfilcnt_t.h>
+#include <bits/posix/fd_set.h>
+
+#include <stdint.h>
+
+#include <sys/select.h>
+
+typedef unsigned int u_int;
+typedef unsigned char u_char;
+typedef unsigned short u_short;
+typedef unsigned long int u_long;
+typedef char *caddr_t;
+typedef off64_t loff_t;
+
+typedef unsigned long int ulong;
+typedef unsigned short int ushort;
+typedef unsigned int uint;
+
+typedef uint8_t u_int8_t;
+typedef uint16_t u_int16_t;
+typedef uint32_t u_int32_t;
+typedef uint64_t u_int64_t;
+
+// BSD extensions
+typedef int64_t quad_t;
+typedef uint64_t u_quad_t;
+
+#endif // _SYS_TYPES_H
+
diff --git a/lib/mlibc/options/posix/include/sys/uio.h b/lib/mlibc/options/posix/include/sys/uio.h
new file mode 100644
index 0000000..04679a6
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/uio.h
@@ -0,0 +1,31 @@
+#ifndef _SYS_UIO_H
+#define _SYS_UIO_H
+
+#include <bits/posix/iovec.h>
+#include <bits/ssize_t.h>
+#include <bits/off_t.h>
+#include <bits/size_t.h>
+#include <limits.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define UIO_MAXIOV IOV_MAX
+
+#ifndef __MLIBC_ABI_ONLY
+
+ssize_t readv(int fd, const struct iovec *iov, int iovcnt);
+ssize_t writev(int fd, const struct iovec *iov, int iovcnt);
+
+// Non standard extensions, also found on modern BSD's
+ssize_t preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset);
+ssize_t pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_UIO_H
diff --git a/lib/mlibc/options/posix/include/sys/un.h b/lib/mlibc/options/posix/include/sys/un.h
new file mode 100644
index 0000000..bb9b5ad
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/un.h
@@ -0,0 +1,24 @@
+
+#ifndef _SYS_UN_H
+#define _SYS_UN_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <abi-bits/socket.h>
+
+struct sockaddr_un {
+	sa_family_t sun_family;
+	char sun_path[108];
+};
+
+// Evaluate to actual length of the `sockaddr_un' structure.
+#define SUN_LEN(ptr) ((size_t) offsetof(struct sockaddr_un, sun_path) + strlen((ptr)->sun_path))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_UN_H
+
diff --git a/lib/mlibc/options/posix/include/sys/utsname.h b/lib/mlibc/options/posix/include/sys/utsname.h
new file mode 100644
index 0000000..bd7b174
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/utsname.h
@@ -0,0 +1,22 @@
+
+#ifndef _SYS_UTSNAME_H
+#define _SYS_UTSNAME_H
+
+#include <abi-bits/utsname.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int uname(struct utsname *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_UTSNAME_H
+
diff --git a/lib/mlibc/options/posix/include/sys/wait.h b/lib/mlibc/options/posix/include/sys/wait.h
new file mode 100644
index 0000000..5081041
--- /dev/null
+++ b/lib/mlibc/options/posix/include/sys/wait.h
@@ -0,0 +1,40 @@
+
+#ifndef _SYS_WAIT_H
+#define _SYS_WAIT_H
+
+#include <bits/posix/id_t.h>
+#include <abi-bits/pid_t.h>
+// for siginfo_t
+#include <abi-bits/signal.h>
+#include <abi-bits/wait.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// According to POSIX, <sys/wait.h> does not make rusage available.
+struct rusage;
+
+// TODO: move to own file and include in sys/types.h
+typedef enum {
+	P_ALL, P_PID, P_PGID
+} idtype_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+pid_t wait(int *status);
+int waitid(idtype_t idtype, id_t id, siginfo_t *siginfo, int flags);
+pid_t waitpid(pid_t pid, int *status, int flags);
+
+// GNU extensions.
+pid_t wait3(int *, int, struct rusage *);
+pid_t wait4(pid_t pid, int *status, int options, struct rusage *ru);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYS_WAIT_H
+
diff --git a/lib/mlibc/options/posix/include/syslog.h b/lib/mlibc/options/posix/include/syslog.h
new file mode 100644
index 0000000..6c258cf
--- /dev/null
+++ b/lib/mlibc/options/posix/include/syslog.h
@@ -0,0 +1,75 @@
+
+#ifndef _SYSLOG_H
+#define _SYSLOG_H
+
+#include <stdarg.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define LOG_PID 0x01
+#define LOG_CONS 0x02
+#define LOG_NDELAY 0x08
+#define LOG_ODELAY 0x04
+#define LOG_NOWAIT 0x10
+#define LOG_PERROR 0x20
+
+#define LOG_KERN (0<<3)
+#define LOG_USER (1<<3)
+#define LOG_MAIL (2<<3)
+#define LOG_DAEMON (3<<3)
+#define LOG_AUTH (4<<3)
+#define LOG_SYSLOG (5<<3)
+#define LOG_LPR (6<<3)
+#define LOG_NEWS (7<<3)
+#define LOG_UUCP (8<<3)
+#define LOG_CRON (9<<3)
+#define LOG_AUTHPRIV (10<<3)
+#define LOG_FTP (11<<3)
+
+#define LOG_LOCAL0 (16<<3)
+#define LOG_LOCAL1 (17<<3)
+#define LOG_LOCAL2 (18<<3)
+#define LOG_LOCAL3 (19<<3)
+#define LOG_LOCAL4 (20<<3)
+#define LOG_LOCAL5 (21<<3)
+#define LOG_LOCAL6 (22<<3)
+#define LOG_LOCAL7 (23<<3)
+
+#define LOG_PRIMASK 7
+#define LOG_PRI(p) ((p)&LOG_PRIMASK)
+#define LOG_MAKEPRI(f, p) (((f)<<3) | (p))
+#define LOG_MASK(p) (1<<(p))
+#define LOG_UPTO(p) ((1<<((p)+1))-1)
+#define LOG_NFACILITIES 24
+#define LOG_FACMASK (0x7F<<3)
+#define LOG_FAC(p) (((p)&LOG_FACMASK)>>3)
+
+#define LOG_EMERG 0
+#define LOG_ALERT 1
+#define LOG_CRIT 2
+#define LOG_ERR 3
+#define LOG_WARNING 4
+#define LOG_NOTICE 5
+#define LOG_INFO 6
+#define LOG_DEBUG 7
+
+#ifndef __MLIBC_ABI_ONLY
+
+void closelog(void);
+void openlog(const char *, int, int);
+int setlogmask(int);
+void syslog(int, const char *, ...);
+
+// This is a linux extension
+void vsyslog(int, const char *, va_list);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _SYSLOG_H
+
diff --git a/lib/mlibc/options/posix/include/termios.h b/lib/mlibc/options/posix/include/termios.h
new file mode 100644
index 0000000..a5a6a2f
--- /dev/null
+++ b/lib/mlibc/options/posix/include/termios.h
@@ -0,0 +1,100 @@
+
+#ifndef _TERMIOS_H
+#define _TERMIOS_H
+
+#include <abi-bits/pid_t.h>
+#include <abi-bits/termios.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/winsize.h>
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#include <sys/ttydefaults.h>
+#endif
+
+// baud rate constants for speed_t
+#define B0       0
+#define B50      1
+#define B75      2
+#define B110     3
+#define B134     4
+#define B150     5
+#define B200     6
+#define B300     7
+#define B600     8
+#define B1200    9
+#define B1800    10
+#define B2400    11
+#define B4800    12
+#define B9600    13
+#define B19200   14
+#define B38400   15
+#define B57600   0010001
+#define B115200  0010002
+#define B230400  0010003
+#define B460800  0010004
+#define B500000  0010005
+#define B576000  0010006
+#define B921600  0010007
+#define B1000000 0010010
+#define B1152000 0010011
+#define B1500000 0010012
+#define B2000000 0010013
+#define B2500000 0010014
+#define B3000000 0010015
+#define B3500000 0010016
+#define B4000000 0010017
+
+// constants for tcsetattr()
+#define TCSANOW 0
+#define TCSADRAIN 1
+#define TCSAFLUSH 2
+
+// constants for tcflush()
+#define TCIFLUSH 0
+#define TCOFLUSH 1
+#define TCIOFLUSH 2
+
+// constants for tcflow()
+#define TCOOFF 0
+#define TCOON 1
+#define TCIOFF 2
+#define TCION 3
+
+#define TIOCM_DTR 0x002
+#define TIOCM_RTS 0x004
+
+#ifndef __MLIBC_ABI_ONLY
+
+speed_t cfgetispeed(const struct termios *);
+speed_t cfgetospeed(const struct termios *);
+int cfsetispeed(struct termios *, speed_t);
+int cfsetospeed(struct termios *, speed_t);
+void cfmakeraw(struct termios *);
+int tcdrain(int);
+int tcflow(int, int);
+int tcflush(int, int);
+int tcgetattr(int fd, struct termios *attr);
+pid_t tcgetsid(int);
+int tcsendbreak(int, int);
+int tcsetattr(int, int, const struct termios *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+// This is a linux extension
+
+#define TIOCGPGRP 0x540F
+#define TIOCSPGRP 0x5410
+#define TIOCGWINSZ 0x5413
+#define TIOCSWINSZ 0x5414
+#define TIOCGSID 0x5429
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _TERMIOS_H
+
diff --git a/lib/mlibc/options/posix/include/ucontext.h b/lib/mlibc/options/posix/include/ucontext.h
new file mode 100644
index 0000000..c50b0b1
--- /dev/null
+++ b/lib/mlibc/options/posix/include/ucontext.h
@@ -0,0 +1,23 @@
+#ifndef _UCONTEXT_H
+#define _UCONTEXT_H
+
+#include <signal.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+#ifndef __MLIBC_ABI_ONLY
+
+int getcontext(ucontext_t *);
+int setcontext(const ucontext_t *);
+void makecontext(ucontext_t *, void (*)(void), int, ...);
+int swapcontext(ucontext_t *, const ucontext_t *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
+#endif // _UCONTEXT_H
diff --git a/lib/mlibc/options/posix/include/unistd.h b/lib/mlibc/options/posix/include/unistd.h
new file mode 100644
index 0000000..d29257d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/unistd.h
@@ -0,0 +1,360 @@
+
+#ifndef _UNISTD_H
+#define _UNISTD_H
+
+#include <mlibc-config.h>
+#include <bits/types.h>
+#include <bits/size_t.h>
+#include <bits/ssize_t.h>
+#include <bits/off_t.h>
+#include <bits/types.h>
+#include <abi-bits/access.h>
+#include <abi-bits/uid_t.h>
+#include <abi-bits/gid_t.h>
+#include <abi-bits/pid_t.h>
+#include <abi-bits/seek-whence.h>
+
+#if __MLIBC_SYSDEP_HAS_BITS_SYSCALL_H && __MLIBC_LINUX_OPTION
+#include <bits/syscall.h>
+#endif /* __MLIBC_SYSDEP_HAS_BITS_SYSCALL_H && __MLIBC_LINUX_OPTION */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define _POSIX_VERSION 200809L
+#define _POSIX2_VERSION _POSIX_VERSION
+#define _XOPEN_VERSION 700
+
+#define _POSIX_FSYNC _POSIX_VERSION
+#define _POSIX_IPV6 _POSIX_VERSION
+#define _POSIX_JOB_CONTROL 1
+#define _POSIX_SAVED_IDS 1
+#define _POSIX_SHELL 1
+#define _POSIX_SPAWN _POSIX_VERSION
+#define _POSIX_THREADS _POSIX_VERSION
+#define _POSIX_THREAD_SAFE_FUNCTIONS _POSIX_VERSION
+#define _POSIX_MONOTONIC_CLOCK 0
+
+#if __MLIBC_CRYPT_OPTION
+#define _XOPEN_CRYPT 1
+#endif
+
+// MISSING: additional _POSIX and _XOPEN feature macros
+// MISSING: _POSIX_TIMESTAMP_RESOLUTION and _POSIX2_SYMLINKS
+
+#define _CS_PATH 0
+#define _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS 1
+#define _CS_GNU_LIBC_VERSION 2
+#define _CS_GNU_LIBPTHREAD_VERSION 3
+#define _CS_POSIX_V5_WIDTH_RESTRICTED_ENVS 4
+#define _CS_POSIX_V7_WIDTH_RESTRICTED_ENVS 5
+
+#define _CS_POSIX_V6_ILP32_OFF32_CFLAGS 1116
+#define _CS_POSIX_V6_ILP32_OFF32_LDFLAGS 1117
+#define _CS_POSIX_V6_ILP32_OFF32_LIBS 1118
+#define _CS_POSIX_V6_ILP32_OFF32_LINTFLAGS 1119
+#define _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS 1120
+#define _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS 1121
+#define _CS_POSIX_V6_ILP32_OFFBIG_LIBS 1122
+#define _CS_POSIX_V6_ILP32_OFFBIG_LINTFLAGS 1123
+#define _CS_POSIX_V6_LP64_OFF64_CFLAGS 1124
+#define _CS_POSIX_V6_LP64_OFF64_LDFLAGS 1125
+#define _CS_POSIX_V6_LP64_OFF64_LIBS 1126
+#define _CS_POSIX_V6_LP64_OFF64_LINTFLAGS 1127
+#define _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS 1128
+#define _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS 1129
+#define _CS_POSIX_V6_LPBIG_OFFBIG_LIBS 1130
+#define _CS_POSIX_V6_LPBIG_OFFBIG_LINTFLAGS 1131
+#define _CS_POSIX_V7_ILP32_OFF32_CFLAGS 1132
+#define _CS_POSIX_V7_ILP32_OFF32_LDFLAGS 1133
+#define _CS_POSIX_V7_ILP32_OFF32_LIBS 1134
+#define _CS_POSIX_V7_ILP32_OFF32_LINTFLAGS 1135
+#define _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS 1136
+#define _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS 1137
+#define _CS_POSIX_V7_ILP32_OFFBIG_LIBS 1138
+#define _CS_POSIX_V7_ILP32_OFFBIG_LINTFLAGS 1139
+#define _CS_POSIX_V7_LP64_OFF64_CFLAGS 1140
+#define _CS_POSIX_V7_LP64_OFF64_LDFLAGS 1141
+#define _CS_POSIX_V7_LP64_OFF64_LIBS 1142
+#define _CS_POSIX_V7_LP64_OFF64_LINTFLAGS 1143
+#define _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS 1144
+#define _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS 1145
+#define _CS_POSIX_V7_LPBIG_OFFBIG_LIBS 1146
+#define _CS_POSIX_V7_LPBIG_OFFBIG_LINTFLAGS 1147
+#define _CS_V6_ENV 1148
+#define _CS_V7_ENV 1149
+
+// MISSING: SEEK macros from stdio.h
+
+#define F_LOCK 1
+#define F_TEST 2
+#define F_TLOCK 3
+#define F_ULOCK 4
+
+// MISSING: _PC macros
+// For now, use the Linux ABI for _PC constants.
+#define _PC_LINK_MAX		0
+#define _PC_MAX_CANON		1
+#define _PC_MAX_INPUT		2
+#define _PC_NAME_MAX		3
+#define _PC_PATH_MAX		4
+#define _PC_PIPE_BUF		5
+#define _PC_CHOWN_RESTRICTED	6
+#define _PC_NO_TRUNC		7
+#define _PC_VDISABLE		8
+
+#define _PC_FILESIZEBITS 9
+#define _PC_SYMLINK_MAX 10
+
+// MISSING: remaining _SC_macros
+#define _SC_ARG_MAX 0
+#define _SC_GETPW_R_SIZE_MAX 1
+#define _SC_PHYS_PAGES 2
+#define _SC_PAGE_SIZE 3
+#define _SC_PAGESIZE _SC_PAGE_SIZE
+#define _SC_OPEN_MAX 5
+#define _SC_NPROCESSORS_ONLN 6
+#define _SC_GETGR_R_SIZE_MAX 7
+
+#define _SC_CHILD_MAX 8
+#define _SC_CLK_TCK 9
+#define _SC_NGROUPS_MAX 10
+#define _SC_VERSION 11
+#define _SC_SAVED_IDS 12
+#define _SC_JOB_CONTROL 13
+#define _SC_HOST_NAME_MAX 14
+#define _SC_LINE_MAX 15
+#define _SC_XOPEN_CRYPT 16
+#define _SC_NPROCESSORS_CONF 17
+#define _SC_SYMLOOP_MAX 18
+#define _SC_TTY_NAME_MAX 19
+#define _SC_RE_DUP_MAX 20
+
+#define _SC_ATEXIT_MAX 21
+#define _SC_LOGIN_NAME_MAX 22
+#define _SC_THREAD_DESTRUCTOR_ITERATIONS 23
+#define _SC_THREAD_KEYS_MAX 24
+#define _SC_THREAD_STACK_MIN 25
+#define _SC_THREAD_THREADS_MAX 26
+#define _SC_TZNAME_MAX 27
+#define _SC_ASYNCHRONOUS_IO 28
+#define _SC_FSYNC 29
+#define _SC_MAPPED_FILES 30
+#define _SC_MEMLOCK 31
+#define _SC_MEMLOCK_RANGE 32
+#define _SC_MEMORY_PROTECTION 33
+#define _SC_MESSAGE_PASSING 34
+#define _SC_PRIORITY_SCHEDULING 35
+#define _SC_REALTIME_SIGNALS 36
+#define _SC_SEMAPHORES 37
+#define _SC_SHARED_MEMORY_OBJECTS 38
+#define _SC_SYNCHRONIZED_IO 39
+#define _SC_THREADS 40
+#define _SC_THREAD_ATTR_STACKADDR 41
+#define _SC_THREAD_ATTR_STACKSIZE 42
+#define _SC_THREAD_PRIORITY_SCHEDULING 43
+#define _SC_THREAD_PRIO_INHERIT 44
+#define _SC_THREAD_PRIO_PROTECT 45
+#define _SC_THREAD_PROCESS_SHARED 46
+#define _SC_THREAD_SAFE_FUNCTIONS 47
+#define _SC_TIMERS 48
+#define _SC_TIMER_MAX 49
+#define _SC_2_CHAR_TERM 50
+#define _SC_2_C_BIND 51
+#define _SC_2_C_DEV 52
+#define _SC_2_FORT_DEV 53
+#define _SC_2_FORT_RUN 54
+#define _SC_2_LOCALEDEF 55
+#define _SC_2_SW_DEV 56
+#define _SC_2_UPE 57
+#define _SC_2_VERSION 58
+#define _SC_CLOCK_SELECTION 59
+#define _SC_CPUTIME 60
+#define _SC_THREAD_CPUTIME 61
+#define _SC_MONOTONIC_CLOCK 62
+#define _SC_READER_WRITER_LOCKS 63
+#define _SC_SPIN_LOCKS 64
+#define _SC_REGEXP 65
+#define _SC_SHELL 66
+#define _SC_SPAWN 67
+#define _SC_2_PBS 68
+#define _SC_2_PBS_ACCOUNTING 69
+#define _SC_2_PBS_LOCATE 70
+#define _SC_2_PBS_TRACK 71
+#define _SC_2_PBS_MESSAGE 72
+#define _SC_STREAM_MAX 73
+#define _SC_AIO_LISTIO_MAX 74
+#define _SC_AIO_MAX 75
+#define _SC_DELAYTIMER_MAX 76
+#define _SC_MQ_OPEN_MAX 77
+#define _SC_MQ_PRIO_MAX 78
+#define _SC_RTSIG_MAX 79
+#define _SC_SIGQUEUE_MAX 80
+#define _SC_IOV_MAX 81
+
+#define STDERR_FILENO 2
+#define STDIN_FILENO 0
+#define STDOUT_FILENO 1
+
+#define _POSIX_VDISABLE '\0'
+
+#define L_ctermid 20
+
+#ifndef intptr_t
+typedef __mlibc_intptr intptr_t;
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int access(const char *path, int mode);
+unsigned int alarm(unsigned int seconds);
+int chdir(const char *path);
+int chown(const char *path, uid_t uid, gid_t gid);
+int close(int fd);
+ssize_t confstr(int, char *, size_t);
+char *ctermid(char *s);
+int dup(int fd);
+int dup2(int src_fd, int dest_fd);
+__attribute__((__noreturn__)) void _exit(int status);
+void endusershell(void);
+int execl(const char *, const char *, ...);
+int execle(const char *, const char *, ...);
+int execlp(const char *, const char *, ...);
+int execv(const char *, char *const []);
+int execve(const char *path, char *const argv[], char *const envp[]);
+int execvp(const char *, char *const[]);
+int execvpe(const char *path, char *const argv[], char *const envp[]);
+int faccessat(int, const char *, int, int);
+int fchdir(int fd);
+int fchown(int fd, uid_t uid, gid_t gid);
+int fchownat(int fd, const char *path, uid_t uid, gid_t gid, int flags);
+int fdatasync(int);
+int fexecve(int, char *const [], char *const []);
+pid_t fork(void);
+pid_t vfork(void);
+long fpathconf(int, int);
+int fsync(int);
+int ftruncate(int, off_t);
+char *getcwd(char *, size_t);
+gid_t getegid(void);
+uid_t geteuid(void);
+gid_t getgid(void);
+int getgroups(int, gid_t []);
+long gethostid(void);
+int gethostname(char *buffer, size_t max_length);
+int sethostname(const char *buffer, size_t max_length);
+char *getlogin(void);
+int getlogin_r(char *, size_t);
+int getopt(int, char *const [], const char *);
+char *getpass(const char *);
+pid_t getpgid(pid_t);
+pid_t getpgrp(void);
+pid_t getpid(void);
+pid_t getppid(void);
+pid_t getsid(pid_t);
+uid_t getuid(void);
+char *getusershell(void);
+int isatty(int fd);
+int lchown(const char *path, uid_t uid, gid_t gid);
+int link(const char *, const char *);
+int linkat(int, const char *, int, const char *, int);
+int lockf(int, int, off_t);
+off_t lseek(int fd, off_t offset, int whence);
+off64_t lseek64(int fd, off64_t offset, int whence);
+int nice(int);
+long pathconf(const char *, int);
+int pause(void);
+int pipe(int [2]);
+ssize_t pread(int, void *, size_t, off_t);
+ssize_t pwrite(int, const void *, size_t, off_t);
+ssize_t read(int fd, void *buffer, size_t size);
+ssize_t readlink(const char *__restrict, char *__restrict, size_t);
+ssize_t readlinkat(int, const char *__restrict, char *__restrict, size_t);
+int rmdir(const char *);
+int setegid(gid_t);
+int seteuid(uid_t);
+int setgid(gid_t);
+int setpgid(pid_t, pid_t);
+pid_t setpgrp(void);
+int setregid(gid_t, gid_t);
+int setreuid(uid_t, uid_t);
+pid_t setsid(void);
+int setuid(uid_t);
+void setusershell(void);
+unsigned int sleep(unsigned int);
+void swab(const void *__restrict, void *__restrict, ssize_t);
+int symlink(const char *, const char *);
+int symlinkat(const char *, int, const char *);
+void sync(void);
+long sysconf(int);
+pid_t tcgetpgrp(int);
+int tcsetpgrp(int, pid_t);
+int truncate(const char *, off_t);
+char *ttyname(int);
+int ttyname_r(int, char *, size_t);
+int unlink(const char *);
+int unlinkat(int, const char *, int);
+ssize_t write(int fd, const void *buffer, size_t size);
+
+extern char **environ;
+extern char *optarg;
+extern int optind;
+extern int opterr;
+extern int optopt;
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+// Non-POSIX functions supported by Linux.
+#if UINTPTR_MAX == UINT64_MAX
+typedef __mlibc_uint64 useconds_t;
+#else
+typedef __mlibc_uint32 useconds_t;
+#endif
+
+#ifndef __MLIBC_ABI_ONLY
+
+int getpagesize(void);
+char *get_current_dir_name(void);
+int usleep(useconds_t);
+int chroot(const char *);
+int daemon(int, int);
+
+// This is a Linux extension
+pid_t gettid(void);
+int getentropy(void *, size_t);
+
+int pipe2(int *pipefd, int flags);
+
+int setresuid(uid_t ruid, uid_t euid, uid_t suid);
+int setresgid(gid_t rgid, gid_t egid, gid_t sgid);
+
+/* Glibc extensions. */
+int getdomainname(char *name, size_t len);
+int setdomainname(const char *name, size_t len);
+
+int getresuid(uid_t *ruid, uid_t *euid, uid_t *suid);
+int getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid);
+
+// Glibc doesn't provide them by default anymore, lock behind an option
+#if __MLIBC_CRYPT_OPTION
+char *crypt(const char *, const char *);
+void encrypt(char block[64], int flags);
+#endif
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#if __MLIBC_LINUX_OPTION
+#	include <bits/linux/linux_unistd.h>
+#endif
+
+#if __MLIBC_BSD_OPTION
+#	include <bits/bsd/bsd_unistd.h>
+#endif
+
+#endif // _UNISTD_H
+
diff --git a/lib/mlibc/options/posix/include/utime.h b/lib/mlibc/options/posix/include/utime.h
new file mode 100644
index 0000000..dcf053d
--- /dev/null
+++ b/lib/mlibc/options/posix/include/utime.h
@@ -0,0 +1,25 @@
+#ifndef _UTIME_H
+#define _UTIME_H
+
+#include <bits/ansi/time_t.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct utimbuf {
+	time_t actime;
+	time_t modtime;
+};
+
+#ifndef __MLIBC_ABI_ONLY
+
+int utime(const char *, const struct utimbuf *);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _UTIME_H
diff --git a/lib/mlibc/options/posix/include/wordexp.h b/lib/mlibc/options/posix/include/wordexp.h
new file mode 100644
index 0000000..e5d69ce
--- /dev/null
+++ b/lib/mlibc/options/posix/include/wordexp.h
@@ -0,0 +1,43 @@
+#ifndef _WORDEXP_H
+#define _WORDEXP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <bits/size_t.h>
+
+#define WRDE_APPEND 1
+#define WRDE_DOOFFS 2
+#define WRDE_NOCMD 4
+#define WRDE_REUSE 8
+#define WRDE_SHOWERR 16
+#define WRDE_UNDEF 32
+
+#define WRDE_SUCCESS 1
+#define WRDE_BADCHAR 1
+#define WRDE_BADVAL 2
+#define WRDE_CMDSUB 3
+#define WRDE_NOSPACE 4
+#define WRDE_SYNTAX 5
+
+typedef struct {
+	size_t we_wordc;
+	char **we_wordv;
+	size_t we_offs;
+	char *we_strings;
+	size_t we_nbytes;
+} wordexp_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+int wordexp(const char *s, wordexp_t *p, int flags);
+void wordfree(wordexp_t *p);
+
+#endif /* !__MLIBC_ABI_ONLY */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib/mlibc/options/posix/meson.build b/lib/mlibc/options/posix/meson.build
new file mode 100644
index 0000000..038dd2c
--- /dev/null
+++ b/lib/mlibc/options/posix/meson.build
@@ -0,0 +1,175 @@
+
+if disable_posix_option
+	subdir_done()
+endif
+libc_sources += files(
+	'generic/arpa-inet-stubs.cpp',
+	'generic/dirent-stubs.cpp',
+	'generic/dlfcn-stubs.cpp',
+	'generic/fcntl-stubs.cpp',
+	'generic/ftw-stubs.cpp',
+	'generic/grp-stubs.cpp',
+	'generic/langinfo-stubs.cpp',
+	'generic/libgen-stubs.cpp',
+	'generic/lookup.cpp',
+	'generic/netdb-stubs.cpp',
+	'generic/net-if-stubs.cpp',
+	'generic/poll.cpp',
+	'generic/posix_ctype.cpp',
+	'generic/posix-file-io.cpp',
+	'generic/posix_locale.cpp',
+	'generic/posix_signal.cpp',
+	'generic/posix_stdio.cpp',
+	'generic/posix_stdlib.cpp',
+	'generic/posix_string.cpp',
+	'generic/posix_time.cpp',
+	'generic/pthread-stubs.cpp',
+	'generic/pwd-stubs.cpp',
+	'generic/resolv_conf.cpp',
+	'generic/sched-stubs.cpp',
+	'generic/spawn-stubs.cpp',
+	'generic/strings-stubs.cpp',
+	'generic/services.cpp',
+	'generic/sys-file-stubs.cpp',
+	'generic/syslog-stubs.cpp',
+	'generic/sys-mman-stubs.cpp',
+	'generic/sys-resource-stubs.cpp',
+	'generic/sys-select-stubs.cpp',
+	'generic/sys-shm.cpp',
+	'generic/sys-socket-stubs.cpp',
+	'generic/sys-stat-stubs.cpp',
+	'generic/sys-statvfs-stubs.cpp',
+	'generic/sys-times.cpp',
+	'generic/sys-time-stubs.cpp',
+	'generic/sys-uio.cpp',
+	'generic/sys-utsname.cpp',
+	'generic/sys-wait-stubs.cpp',
+	'generic/termios-stubs.cpp',
+	'generic/unistd-stubs.cpp',
+	'generic/utime-stubs.cpp',
+	'generic/ucontext-stubs.cpp',
+	'generic/semaphore-stubs.cpp',
+	'generic/search.cpp',
+	'generic/sys-msg.cpp',
+	'generic/sys-sem.cpp',
+	'generic/sys-ipc.cpp',
+	'generic/time.cpp',
+	'generic/wordexp-stubs.cpp',
+	'generic/mqueue.cpp'
+)
+
+if not headers_only
+	libc_sublibs += static_library('musl-generic-regex',
+		'musl-generic-regex/fnmatch.c',
+		'musl-generic-regex/glob.c',
+		'musl-generic-regex/regcomp.c',
+		'musl-generic-regex/regerror.c',
+		'musl-generic-regex/regexec.c',
+		'musl-generic-regex/tre-mem.c',
+		pic: true,
+		include_directories: libc_include_dirs,
+		dependencies: libc_deps,
+		c_args: ['-Wno-unused', '-Wno-implicit', '-Wno-parentheses', '-Wno-sign-compare', '-Wno-attributes', '-Wno-unknown-pragmas', '-Wno-implicit-fallthrough']
+	)
+endif
+
+if not no_headers
+	install_headers(
+		'include/byteswap.h',
+		'include/dirent.h',
+		'include/dlfcn.h',
+		'include/fcntl.h',
+		'include/fnmatch.h',
+		'include/ftw.h',
+		'include/glob.h',
+		'include/grp.h',
+		'include/langinfo.h',
+		'include/libgen.h',
+		'include/netdb.h',
+		'include/nl_types.h',
+		'include/pthread.h',
+		'include/pwd.h',
+		'include/poll.h',
+		'include/regex.h',
+		'include/sched.h',
+		'include/search.h',
+		'include/spawn.h',
+		'include/strings.h',
+		'include/syslog.h',
+		'include/termios.h',
+		'include/unistd.h',
+		'include/utime.h',
+		'include/ucontext.h',
+		'include/wordexp.h',
+		'include/semaphore.h',
+		'include/mqueue.h',
+	)
+	install_headers(
+		'include/arpa/inet.h',
+		subdir: 'arpa'
+	)
+	install_headers(
+		'include/net/if.h',
+		'include/net/if_arp.h',
+		subdir: 'net'
+	)
+	install_headers(
+		'include/netinet/in.h',
+		'include/netinet/ip.h',
+		'include/netinet/tcp.h',
+		'include/netinet/icmp6.h',
+		'include/netinet/if_ether.h',
+		'include/netinet/udp.h',
+		'include/netinet/ip6.h',
+		'include/netinet/ip_icmp.h',
+		subdir: 'netinet'
+	)
+	install_headers(
+		'include/sys/file.h',
+		'include/sys/ipc.h',
+		'include/sys/mman.h',
+		'include/sys/msg.h',
+		'include/sys/param.h',
+		'include/sys/poll.h',
+		'include/sys/resource.h',
+		'include/sys/select.h',
+		'include/sys/sem.h',
+		'include/sys/shm.h',
+		'include/sys/socket.h',
+		'include/sys/stat.h',
+		'include/sys/statvfs.h',
+		'include/sys/termios.h',
+		'include/sys/time.h',
+		'include/sys/times.h',
+		'include/sys/ttydefaults.h',
+		'include/sys/types.h',
+		'include/sys/uio.h',
+		'include/sys/un.h',
+		'include/sys/utsname.h',
+		'include/sys/wait.h',
+		'include/sys/syslog.h',
+		subdir: 'sys'
+	)
+	install_headers(
+		'include/bits/posix/id_t.h',
+		'include/bits/posix/in_addr_t.h',
+		'include/bits/posix/in_port_t.h',
+		'include/bits/posix/iovec.h',
+		'include/bits/posix/locale_t.h',
+		'include/bits/posix/posix_ctype.h',
+		'include/bits/posix/posix_locale.h',
+		'include/bits/posix/posix_signal.h',
+		'include/bits/posix/posix_stdio.h',
+		'include/bits/posix/posix_stdlib.h',
+		'include/bits/posix/posix_string.h',
+		'include/bits/posix/posix_time.h',
+		'include/bits/posix/posix_wctype.h',
+		'include/bits/posix/stat.h',
+		'include/bits/posix/timeval.h',
+		'include/bits/posix/fd_set.h',
+		'include/bits/posix/pthread_t.h',
+		'include/bits/posix/timer_t.h',
+		subdir: 'bits/posix'
+	)
+endif
+
diff --git a/lib/mlibc/options/posix/musl-generic-regex/fnmatch.c b/lib/mlibc/options/posix/musl-generic-regex/fnmatch.c
new file mode 100644
index 0000000..0e6de47
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/fnmatch.c
@@ -0,0 +1,321 @@
+/*
+ * An implementation of what I call the "Sea of Stars" algorithm for
+ * POSIX fnmatch(). The basic idea is that we factor the pattern into
+ * a head component (which we match first and can reject without ever
+ * measuring the length of the string), an optional tail component
+ * (which only exists if the pattern contains at least one star), and
+ * an optional "sea of stars", a set of star-separated components
+ * between the head and tail. After the head and tail matches have
+ * been removed from the input string, the components in the "sea of
+ * stars" are matched sequentially by searching for their first
+ * occurrence past the end of the previous match.
+ *
+ * - Rich Felker, April 2012
+ */
+
+#include <string.h>
+#include <fnmatch.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include <wctype.h>
+// #include "locale_impl.h"
+
+#define END 0
+#define UNMATCHABLE -2
+#define BRACKET -3
+#define QUESTION -4
+#define STAR -5
+
+static int str_next(const char *str, size_t n, size_t *step)
+{
+	if (!n) {
+		*step = 0;
+		return 0;
+	}
+	if (str[0] >= 128U) {
+		wchar_t wc;
+		int k = mbtowc(&wc, str, n);
+		if (k<0) {
+			*step = 1;
+			return -1;
+		}
+		*step = k;
+		return wc;
+	}
+	*step = 1;
+	return str[0];
+}
+
+static int pat_next(const char *pat, size_t m, size_t *step, int flags)
+{
+	int esc = 0;
+	if (!m || !*pat) {
+		*step = 0;
+		return END;
+	}
+	*step = 1;
+	if (pat[0]=='\\' && pat[1] && !(flags & FNM_NOESCAPE)) {
+		*step = 2;
+		pat++;
+		esc = 1;
+		goto escaped;
+	}
+	if (pat[0]=='[') {
+		size_t k = 1;
+		if (k<m) if (pat[k] == '^' || pat[k] == '!') k++;
+		if (k<m) if (pat[k] == ']') k++;
+		for (; k<m && pat[k] && pat[k]!=']'; k++) {
+			if (k+1<m && pat[k+1] && pat[k]=='[' && (pat[k+1]==':' || pat[k+1]=='.' || pat[k+1]=='=')) {
+				int z = pat[k+1];
+				k+=2;
+				if (k<m && pat[k]) k++;
+				while (k<m && pat[k] && (pat[k-1]!=z || pat[k]!=']')) k++;
+				if (k==m || !pat[k]) break;
+			}
+		}
+		if (k==m || !pat[k]) {
+			*step = 1;
+			return '[';
+		}
+		*step = k+1;
+		return BRACKET;
+	}
+	if (pat[0] == '*')
+		return STAR;
+	if (pat[0] == '?')
+		return QUESTION;
+escaped:
+	if (pat[0] >= 128U) {
+		wchar_t wc;
+		int k = mbtowc(&wc, pat, m);
+		if (k<0) {
+			*step = 0;
+			return UNMATCHABLE;
+		}
+		*step = k + esc;
+		return wc;
+	}
+	return pat[0];
+}
+
+static int casefold(int k)
+{
+	int c = towupper(k);
+	return c == k ? towlower(k) : c;
+}
+
+static int match_bracket(const char *p, int k, int kfold)
+{
+	wchar_t wc;
+	int inv = 0;
+	p++;
+	if (*p=='^' || *p=='!') {
+		inv = 1;
+		p++;
+	}
+	if (*p==']') {
+		if (k==']') return !inv;
+		p++;
+	} else if (*p=='-') {
+		if (k=='-') return !inv;
+		p++;
+	}
+	wc = p[-1];
+	for (; *p != ']'; p++) {
+		if (p[0]=='-' && p[1]!=']') {
+			wchar_t wc2;
+			int l = mbtowc(&wc2, p+1, 4);
+			if (l < 0) return 0;
+			if (wc <= wc2)
+				if ((unsigned)k-wc <= wc2-wc ||
+				    (unsigned)kfold-wc <= wc2-wc)
+					return !inv;
+			p += l-1;
+			continue;
+		}
+		if (p[0]=='[' && (p[1]==':' || p[1]=='.' || p[1]=='=')) {
+			const char *p0 = p+2;
+			int z = p[1];
+			p+=3;
+			while (p[-1]!=z || p[0]!=']') p++;
+			if (z == ':' && p-1-p0 < 16) {
+				char buf[16];
+				memcpy(buf, p0, p-1-p0);
+				buf[p-1-p0] = 0;
+				if (iswctype(k, wctype(buf)) ||
+				    iswctype(kfold, wctype(buf)))
+					return !inv;
+			}
+			continue;
+		}
+		if (*p < 128U) {
+			wc = (unsigned char)*p;
+		} else {
+			int l = mbtowc(&wc, p, 4);
+			if (l < 0) return 0;
+			p += l-1;
+		}
+		if (wc==(wchar_t)k || wc==(wchar_t)kfold) return !inv;
+	}
+	return inv;
+}
+
+static int fnmatch_internal(const char *pat, size_t m, const char *str, size_t n, int flags)
+{
+	const char *p, *ptail, *endpat;
+	const char *s, *stail, *endstr;
+	size_t pinc, sinc, tailcnt=0;
+	int c, k, kfold;
+
+	if (flags & FNM_PERIOD) {
+		if (*str == '.' && *pat != '.')
+			return FNM_NOMATCH;
+	}
+	for (;;) {
+		switch ((c = pat_next(pat, m, &pinc, flags))) {
+		case UNMATCHABLE:
+			return FNM_NOMATCH;
+		case STAR:
+			pat++;
+			m--;
+			break;
+		default:
+			k = str_next(str, n, &sinc);
+			if (k <= 0)
+				return (c==END) ? 0 : FNM_NOMATCH;
+			str += sinc;
+			n -= sinc;
+			kfold = flags & FNM_CASEFOLD ? casefold(k) : k;
+			if (c == BRACKET) {
+				if (!match_bracket(pat, k, kfold))
+					return FNM_NOMATCH;
+			} else if (c != QUESTION && k != c && kfold != c) {
+				return FNM_NOMATCH;
+			}
+			pat+=pinc;
+			m-=pinc;
+			continue;
+		}
+		break;
+	}
+
+	/* Compute real pat length if it was initially unknown/-1 */
+	m = strnlen(pat, m);
+	endpat = pat + m;
+
+	/* Find the last * in pat and count chars needed after it */
+	for (p=ptail=pat; p<endpat; p+=pinc) {
+		switch (pat_next(p, endpat-p, &pinc, flags)) {
+		case UNMATCHABLE:
+			return FNM_NOMATCH;
+		case STAR:
+			tailcnt=0;
+			ptail = p+1;
+			break;
+		default:
+			tailcnt++;
+			break;
+		}
+	}
+
+	/* Past this point we need not check for UNMATCHABLE in pat,
+	 * because all of pat has already been parsed once. */
+
+	/* Compute real str length if it was initially unknown/-1 */
+	n = strnlen(str, n);
+	endstr = str + n;
+	if (n < tailcnt) return FNM_NOMATCH;
+
+	/* Find the final tailcnt chars of str, accounting for UTF-8.
+	 * On illegal sequences we may get it wrong, but in that case
+	 * we necessarily have a matching failure anyway. */
+	for (s=endstr; s>str && tailcnt; tailcnt--) {
+		if (s[-1] < 128U || MB_CUR_MAX==1) s--;
+		else while ((unsigned char)*--s-0x80U<0x40 && s>str);
+	}
+	if (tailcnt) return FNM_NOMATCH;
+	stail = s;
+
+	/* Check that the pat and str tails match */
+	p = ptail;
+	for (;;) {
+		c = pat_next(p, endpat-p, &pinc, flags);
+		p += pinc;
+		if ((k = str_next(s, endstr-s, &sinc)) <= 0) {
+			if (c != END) return FNM_NOMATCH;
+			break;
+		}
+		s += sinc;
+		kfold = flags & FNM_CASEFOLD ? casefold(k) : k;
+		if (c == BRACKET) {
+			if (!match_bracket(p-pinc, k, kfold))
+				return FNM_NOMATCH;
+		} else if (c != QUESTION && k != c && kfold != c) {
+			return FNM_NOMATCH;
+		}
+	}
+
+	/* We're all done with the tails now, so throw them out */
+	endstr = stail;
+	endpat = ptail;
+
+	/* Match pattern components until there are none left */
+	while (pat<endpat) {
+		p = pat;
+		s = str;
+		for (;;) {
+			c = pat_next(p, endpat-p, &pinc, flags);
+			p += pinc;
+			/* Encountering * completes/commits a component */
+			if (c == STAR) {
+				pat = p;
+				str = s;
+				break;
+			}
+			k = str_next(s, endstr-s, &sinc);
+			if (!k)
+				return FNM_NOMATCH;
+			kfold = flags & FNM_CASEFOLD ? casefold(k) : k;
+			if (c == BRACKET) {
+				if (!match_bracket(p-pinc, k, kfold))
+					break;
+			} else if (c != QUESTION && k != c && kfold != c) {
+				break;
+			}
+			s += sinc;
+		}
+		if (c == STAR) continue;
+		/* If we failed, advance str, by 1 char if it's a valid
+		 * char, or past all invalid bytes otherwise. */
+		k = str_next(str, endstr-str, &sinc);
+		if (k > 0) str += sinc;
+		else for (str++; str_next(str, endstr-str, &sinc)<0; str++);
+	}
+
+	return 0;
+}
+
+int fnmatch(const char *pat, const char *str, int flags)
+{
+	const char *s, *p;
+	size_t inc;
+	int c;
+	if (flags & FNM_PATHNAME) for (;;) {
+		for (s=str; *s && *s!='/'; s++);
+		for (p=pat; (c=pat_next(p, -1, &inc, flags))!=END && c!='/'; p+=inc);
+		if (c!=*s && (!*s || !(flags & FNM_LEADING_DIR)))
+			return FNM_NOMATCH;
+		if (fnmatch_internal(pat, p-pat, str, s-str, flags))
+			return FNM_NOMATCH;
+		if (!c) return 0;
+		str = s+1;
+		pat = p+inc;
+	} else if (flags & FNM_LEADING_DIR) {
+		for (s=str; *s; s++) {
+			if (*s != '/') continue;
+			if (!fnmatch_internal(pat, -1, str, s-str, flags))
+				return 0;
+		}
+	}
+	return fnmatch_internal(pat, -1, str, -1, flags);
+}
diff --git a/lib/mlibc/options/posix/musl-generic-regex/glob.c b/lib/mlibc/options/posix/musl-generic-regex/glob.c
new file mode 100644
index 0000000..b57f2f3
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/glob.c
@@ -0,0 +1,311 @@
+#define _BSD_SOURCE
+#include <glob.h>
+#include <fnmatch.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <limits.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <pwd.h>
+
+struct match
+{
+	struct match *next;
+	char name[];
+};
+
+static int append(struct match **tail, const char *name, size_t len, int mark)
+{
+	struct match *new = malloc(sizeof(struct match) + len + 2);
+	if (!new) return -1;
+	(*tail)->next = new;
+	new->next = NULL;
+	memcpy(new->name, name, len+1);
+	if (mark && len && name[len-1]!='/') {
+		new->name[len] = '/';
+		new->name[len+1] = 0;
+	}
+	*tail = new;
+	return 0;
+}
+
+static int do_glob(char *buf, size_t pos, int type, char *pat, int flags, int (*errfunc)(const char *path, int err), struct match **tail)
+{
+	/* If GLOB_MARK is unused, we don't care about type. */
+	if (!type && !(flags & GLOB_MARK)) type = DT_REG;
+
+	/* Special-case the remaining pattern being all slashes, in
+	 * which case we can use caller-passed type if it's a dir. */
+	if (*pat && type!=DT_DIR) type = 0;
+	while (pos+1 < PATH_MAX && *pat=='/') buf[pos++] = *pat++;
+
+	/* Consume maximal [escaped-]literal prefix of pattern, copying
+	 * and un-escaping it to the running buffer as we go. */
+	ptrdiff_t i=0, j=0;
+	int in_bracket = 0, overflow = 0;
+	for (; pat[i]!='*' && pat[i]!='?' && (!in_bracket || pat[i]!=']'); i++) {
+		if (!pat[i]) {
+			if (overflow) return 0;
+			pat += i;
+			pos += j;
+			i = j = 0;
+			break;
+		} else if (pat[i] == '[') {
+			in_bracket = 1;
+		} else if (pat[i] == '\\' && !(flags & GLOB_NOESCAPE)) {
+			/* Backslashes inside a bracket are (at least by
+			 * our interpretation) non-special, so if next
+			 * char is ']' we have a complete expression. */
+			if (in_bracket && pat[i+1]==']') break;
+			/* Unpaired final backslash never matches. */
+			if (!pat[i+1]) return 0;
+			i++;
+		}
+		if (pat[i] == '/') {
+			if (overflow) return 0;
+			in_bracket = 0;
+			pat += i+1;
+			i = -1;
+			pos += j+1;
+			j = -1;
+		}
+		/* Only store a character if it fits in the buffer, but if
+		 * a potential bracket expression is open, the overflow
+		 * must be remembered and handled later only if the bracket
+		 * is unterminated (and thereby a literal), so as not to
+		 * disallow long bracket expressions with short matches. */
+		if (pos+(j+1) < PATH_MAX) {
+			buf[pos+j++] = pat[i];
+		} else if (in_bracket) {
+			overflow = 1;
+		} else {
+			return 0;
+		}
+		/* If we consume any new components, the caller-passed type
+		 * or dummy type from above is no longer valid. */
+		type = 0;
+	}
+	buf[pos] = 0;
+	if (!*pat) {
+		/* If we consumed any components above, or if GLOB_MARK is
+		 * requested and we don't yet know if the match is a dir,
+		 * we must confirm the file exists and/or determine its type.
+		 *
+		 * If marking dirs, symlink type is inconclusive; we need the
+		 * type for the symlink target, and therefore must try stat
+		 * first unless type is known not to be a symlink. Otherwise,
+		 * or if that fails, use lstat for determining existence to
+		 * avoid false negatives in the case of broken symlinks. */
+		struct stat st;
+		if ((flags & GLOB_MARK) && (!type||type==DT_LNK) && !stat(buf, &st)) {
+			if (S_ISDIR(st.st_mode)) type = DT_DIR;
+			else type = DT_REG;
+		}
+		if (!type && lstat(buf, &st)) {
+			if (errno!=ENOENT && (errfunc(buf, errno) || (flags & GLOB_ERR)))
+				return GLOB_ABORTED;
+			return 0;
+		}
+		if (append(tail, buf, pos, (flags & GLOB_MARK) && type==DT_DIR))
+			return GLOB_NOSPACE;
+		return 0;
+	}
+	char *p2 = strchr(pat, '/'), saved_sep = '/';
+	/* Check if the '/' was escaped and, if so, remove the escape char
+	 * so that it will not be unpaired when passed to fnmatch. */
+	if (p2 && !(flags & GLOB_NOESCAPE)) {
+		char *p;
+		for (p=p2; p>pat && p[-1]=='\\'; p--);
+		if ((p2-p)%2) {
+			p2--;
+			saved_sep = '\\';
+		}
+	}
+	DIR *dir = opendir(pos ? buf : ".");
+	if (!dir) {
+		if (errfunc(buf, errno) || (flags & GLOB_ERR))
+			return GLOB_ABORTED;
+		return 0;
+	}
+	int old_errno = errno;
+	struct dirent *de;
+	while (errno=0, de=readdir(dir)) {
+		/* Quickly skip non-directories when there's pattern left. */
+		if (p2 && de->d_type && de->d_type!=DT_DIR && de->d_type!=DT_LNK)
+			continue;
+
+		size_t l = strlen(de->d_name);
+		if (l >= PATH_MAX-pos) continue;
+
+		if (p2) *p2 = 0;
+
+		int fnm_flags= ((flags & GLOB_NOESCAPE) ? FNM_NOESCAPE : 0)
+			| ((!(flags & GLOB_PERIOD)) ? FNM_PERIOD : 0);
+
+		if (fnmatch(pat, de->d_name, fnm_flags))
+			continue;
+
+		/* With GLOB_PERIOD, don't allow matching . or .. unless
+		 * fnmatch would match them with FNM_PERIOD rules in effect. */
+		if (p2 && (flags & GLOB_PERIOD) && de->d_name[0]=='.'
+		    && (!de->d_name[1] || de->d_name[1]=='.' && !de->d_name[2])
+		    && fnmatch(pat, de->d_name, fnm_flags | FNM_PERIOD))
+			continue;
+
+		memcpy(buf+pos, de->d_name, l+1);
+		if (p2) *p2 = saved_sep;
+		int r = do_glob(buf, pos+l, de->d_type, p2 ? p2 : "", flags, errfunc, tail);
+		if (r) {
+			closedir(dir);
+			return r;
+		}
+	}
+	int readerr = errno;
+	if (p2) *p2 = saved_sep;
+	closedir(dir);
+	if (readerr && (errfunc(buf, errno) || (flags & GLOB_ERR)))
+		return GLOB_ABORTED;
+	errno = old_errno;
+	return 0;
+}
+
+static int ignore_err(const char *path, int err)
+{
+	return 0;
+}
+
+static void freelist(struct match *head)
+{
+	struct match *match, *next;
+	for (match=head->next; match; match=next) {
+		next = match->next;
+		free(match);
+	}
+}
+
+static int sort(const void *a, const void *b)
+{
+	return strcmp(*(const char **)a, *(const char **)b);
+}
+
+static int expand_tilde(char **pat, char *buf, size_t *pos)
+{
+	char *p = *pat + 1;
+	size_t i = 0;
+
+	char delim, *name_end = strchrnul(p, '/');
+	if ((delim = *name_end)) *name_end++ = 0;
+	*pat = name_end;
+
+	char *home = *p ? NULL : getenv("HOME");
+	if (!home) {
+		struct passwd pw, *res;
+		switch (*p ? getpwnam_r(p, &pw, buf, PATH_MAX, &res)
+			   : getpwuid_r(getuid(), &pw, buf, PATH_MAX, &res)) {
+		case ENOMEM:
+			return GLOB_NOSPACE;
+		case 0:
+			if (!res)
+		default:
+				return GLOB_NOMATCH;
+		}
+		home = pw.pw_dir;
+	}
+	while (i < PATH_MAX - 2 && *home)
+		buf[i++] = *home++;
+	if (*home)
+		return GLOB_NOMATCH;
+	if ((buf[i] = delim))
+		buf[++i] = 0;
+	*pos = i;
+	return 0;
+}
+
+int glob(const char *restrict pat, int flags, int (*errfunc)(const char *path, int err), glob_t *restrict g)
+{
+	struct match head = { .next = NULL }, *tail = &head;
+	size_t cnt, i;
+	size_t offs = (flags & GLOB_DOOFFS) ? g->gl_offs : 0;
+	int error = 0;
+	char buf[PATH_MAX];
+	
+	if (!errfunc) errfunc = ignore_err;
+
+	if (!(flags & GLOB_APPEND)) {
+		g->gl_offs = offs;
+		g->gl_pathc = 0;
+		g->gl_pathv = NULL;
+	}
+
+	if (*pat) {
+		char *p = strdup(pat);
+		if (!p) return GLOB_NOSPACE;
+		buf[0] = 0;
+		size_t pos = 0;
+		char *s = p;
+		if ((flags & (GLOB_TILDE | GLOB_TILDE_CHECK)) && *p == '~')
+			error = expand_tilde(&s, buf, &pos);
+		if (!error)
+			error = do_glob(buf, pos, 0, s, flags, errfunc, &tail);
+		free(p);
+	}
+
+	if (error == GLOB_NOSPACE) {
+		freelist(&head);
+		return error;
+	}
+	
+	for (cnt=0, tail=head.next; tail; tail=tail->next, cnt++);
+	if (!cnt) {
+		if (flags & GLOB_NOCHECK) {
+			tail = &head;
+			if (append(&tail, pat, strlen(pat), 0))
+				return GLOB_NOSPACE;
+			cnt++;
+		} else
+			return GLOB_NOMATCH;
+	}
+
+	if (flags & GLOB_APPEND) {
+		char **pathv = realloc(g->gl_pathv, (offs + g->gl_pathc + cnt + 1) * sizeof(char *));
+		if (!pathv) {
+			freelist(&head);
+			return GLOB_NOSPACE;
+		}
+		g->gl_pathv = pathv;
+		offs += g->gl_pathc;
+	} else {
+		g->gl_pathv = malloc((offs + cnt + 1) * sizeof(char *));
+		if (!g->gl_pathv) {
+			freelist(&head);
+			return GLOB_NOSPACE;
+		}
+		for (i=0; i<offs; i++)
+			g->gl_pathv[i] = NULL;
+	}
+	for (i=0, tail=head.next; i<cnt; tail=tail->next, i++)
+		g->gl_pathv[offs + i] = tail->name;
+	g->gl_pathv[offs + i] = NULL;
+	g->gl_pathc += cnt;
+
+	if (!(flags & GLOB_NOSORT))
+		qsort(g->gl_pathv+offs, cnt, sizeof(char *), sort);
+	
+	return error;
+}
+
+void globfree(glob_t *g)
+{
+	size_t i;
+	for (i=0; i<g->gl_pathc; i++)
+		free(g->gl_pathv[g->gl_offs + i] - offsetof(struct match, name));
+	free(g->gl_pathv);
+	g->gl_pathc = 0;
+	g->gl_pathv = NULL;
+}
+
+// weak_alias(glob, glob64);
+// weak_alias(globfree, globfree64);
diff --git a/lib/mlibc/options/posix/musl-generic-regex/regcomp.c b/lib/mlibc/options/posix/musl-generic-regex/regcomp.c
new file mode 100644
index 0000000..ab03984
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/regcomp.c
@@ -0,0 +1,2953 @@
+/*
+  regcomp.c - TRE POSIX compatible regex compilation functions.
+
+  Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
+  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include <string.h>
+#include <stdlib.h>
+#include <regex.h>
+#include <limits.h>
+#include <stdint.h>
+#include <ctype.h>
+
+#include "tre.h"
+
+#include <assert.h>
+
+/***********************************************************************
+ from tre-compile.h
+***********************************************************************/
+
+typedef struct {
+  int position;
+  int code_min;
+  int code_max;
+  int *tags;
+  int assertions;
+  tre_ctype_t class;
+  tre_ctype_t *neg_classes;
+  int backref;
+} tre_pos_and_tags_t;
+
+
+/***********************************************************************
+ from tre-ast.c and tre-ast.h
+***********************************************************************/
+
+/* The different AST node types. */
+typedef enum {
+  LITERAL,
+  CATENATION,
+  ITERATION,
+  UNION
+} tre_ast_type_t;
+
+/* Special subtypes of TRE_LITERAL. */
+#define EMPTY	  -1   /* Empty leaf (denotes empty string). */
+#define ASSERTION -2   /* Assertion leaf. */
+#define TAG	  -3   /* Tag leaf. */
+#define BACKREF	  -4   /* Back reference leaf. */
+
+#define IS_SPECIAL(x)	((x)->code_min < 0)
+#define IS_EMPTY(x)	((x)->code_min == EMPTY)
+#define IS_ASSERTION(x) ((x)->code_min == ASSERTION)
+#define IS_TAG(x)	((x)->code_min == TAG)
+#define IS_BACKREF(x)	((x)->code_min == BACKREF)
+
+
+/* A generic AST node.  All AST nodes consist of this node on the top
+   level with `obj' pointing to the actual content. */
+typedef struct {
+  tre_ast_type_t type;   /* Type of the node. */
+  void *obj;             /* Pointer to actual node. */
+  int nullable;
+  int submatch_id;
+  int num_submatches;
+  int num_tags;
+  tre_pos_and_tags_t *firstpos;
+  tre_pos_and_tags_t *lastpos;
+} tre_ast_node_t;
+
+
+/* A "literal" node.  These are created for assertions, back references,
+   tags, matching parameter settings, and all expressions that match one
+   character. */
+typedef struct {
+  long code_min;
+  long code_max;
+  int position;
+  tre_ctype_t class;
+  tre_ctype_t *neg_classes;
+} tre_literal_t;
+
+/* A "catenation" node.	 These are created when two regexps are concatenated.
+   If there are more than one subexpressions in sequence, the `left' part
+   holds all but the last, and `right' part holds the last subexpression
+   (catenation is left associative). */
+typedef struct {
+  tre_ast_node_t *left;
+  tre_ast_node_t *right;
+} tre_catenation_t;
+
+/* An "iteration" node.	 These are created for the "*", "+", "?", and "{m,n}"
+   operators. */
+typedef struct {
+  /* Subexpression to match. */
+  tre_ast_node_t *arg;
+  /* Minimum number of consecutive matches. */
+  int min;
+  /* Maximum number of consecutive matches. */
+  int max;
+  /* If 0, match as many characters as possible, if 1 match as few as
+     possible.	Note that this does not always mean the same thing as
+     matching as many/few repetitions as possible. */
+  unsigned int minimal:1;
+} tre_iteration_t;
+
+/* An "union" node.  These are created for the "|" operator. */
+typedef struct {
+  tre_ast_node_t *left;
+  tre_ast_node_t *right;
+} tre_union_t;
+
+
+static tre_ast_node_t *
+tre_ast_new_node(tre_mem_t mem, int type, void *obj)
+{
+	tre_ast_node_t *node = tre_mem_calloc(mem, sizeof *node);
+	if (!node || !obj)
+		return 0;
+	node->obj = obj;
+	node->type = type;
+	node->nullable = -1;
+	node->submatch_id = -1;
+	return node;
+}
+
+static tre_ast_node_t *
+tre_ast_new_literal(tre_mem_t mem, int code_min, int code_max, int position)
+{
+	tre_ast_node_t *node;
+	tre_literal_t *lit;
+
+	lit = tre_mem_calloc(mem, sizeof *lit);
+	node = tre_ast_new_node(mem, LITERAL, lit);
+	if (!node)
+		return 0;
+	lit->code_min = code_min;
+	lit->code_max = code_max;
+	lit->position = position;
+	return node;
+}
+
+static tre_ast_node_t *
+tre_ast_new_iter(tre_mem_t mem, tre_ast_node_t *arg, int min, int max, int minimal)
+{
+	tre_ast_node_t *node;
+	tre_iteration_t *iter;
+
+	iter = tre_mem_calloc(mem, sizeof *iter);
+	node = tre_ast_new_node(mem, ITERATION, iter);
+	if (!node)
+		return 0;
+	iter->arg = arg;
+	iter->min = min;
+	iter->max = max;
+	iter->minimal = minimal;
+	node->num_submatches = arg->num_submatches;
+	return node;
+}
+
+static tre_ast_node_t *
+tre_ast_new_union(tre_mem_t mem, tre_ast_node_t *left, tre_ast_node_t *right)
+{
+	tre_ast_node_t *node;
+	tre_union_t *un;
+
+	if (!left)
+		return right;
+	un = tre_mem_calloc(mem, sizeof *un);
+	node = tre_ast_new_node(mem, UNION, un);
+	if (!node || !right)
+		return 0;
+	un->left = left;
+	un->right = right;
+	node->num_submatches = left->num_submatches + right->num_submatches;
+	return node;
+}
+
+static tre_ast_node_t *
+tre_ast_new_catenation(tre_mem_t mem, tre_ast_node_t *left, tre_ast_node_t *right)
+{
+	tre_ast_node_t *node;
+	tre_catenation_t *cat;
+
+	if (!left)
+		return right;
+	cat = tre_mem_calloc(mem, sizeof *cat);
+	node = tre_ast_new_node(mem, CATENATION, cat);
+	if (!node)
+		return 0;
+	cat->left = left;
+	cat->right = right;
+	node->num_submatches = left->num_submatches + right->num_submatches;
+	return node;
+}
+
+
+/***********************************************************************
+ from tre-stack.c and tre-stack.h
+***********************************************************************/
+
+typedef struct tre_stack_rec tre_stack_t;
+
+/* Creates a new stack object.	`size' is initial size in bytes, `max_size'
+   is maximum size, and `increment' specifies how much more space will be
+   allocated with realloc() if all space gets used up.	Returns the stack
+   object or NULL if out of memory. */
+static tre_stack_t *
+tre_stack_new(int size, int max_size, int increment);
+
+/* Frees the stack object. */
+static void
+tre_stack_destroy(tre_stack_t *s);
+
+/* Returns the current number of objects in the stack. */
+static int
+tre_stack_num_objects(tre_stack_t *s);
+
+/* Each tre_stack_push_*(tre_stack_t *s, <type> value) function pushes
+   `value' on top of stack `s'.  Returns REG_ESPACE if out of memory.
+   This tries to realloc() more space before failing if maximum size
+   has not yet been reached.  Returns REG_OK if successful. */
+#define declare_pushf(typetag, type)					      \
+  static reg_errcode_t tre_stack_push_ ## typetag(tre_stack_t *s, type value)
+
+declare_pushf(voidptr, void *);
+declare_pushf(int, int);
+
+/* Each tre_stack_pop_*(tre_stack_t *s) function pops the topmost
+   element off of stack `s' and returns it.  The stack must not be
+   empty. */
+#define declare_popf(typetag, type)		  \
+  static type tre_stack_pop_ ## typetag(tre_stack_t *s)
+
+declare_popf(voidptr, void *);
+declare_popf(int, int);
+
+/* Just to save some typing. */
+#define STACK_PUSH(s, typetag, value)					      \
+  do									      \
+    {									      \
+      status = tre_stack_push_ ## typetag(s, value);			      \
+    }									      \
+  while (/*CONSTCOND*/0)
+
+#define STACK_PUSHX(s, typetag, value)					      \
+  {									      \
+    status = tre_stack_push_ ## typetag(s, value);			      \
+    if (status != REG_OK)						      \
+      break;								      \
+  }
+
+#define STACK_PUSHR(s, typetag, value)					      \
+  {									      \
+    reg_errcode_t _status;						      \
+    _status = tre_stack_push_ ## typetag(s, value);			      \
+    if (_status != REG_OK)						      \
+      return _status;							      \
+  }
+
+union tre_stack_item {
+  void *voidptr_value;
+  int int_value;
+};
+
+struct tre_stack_rec {
+  int size;
+  int max_size;
+  int increment;
+  int ptr;
+  union tre_stack_item *stack;
+};
+
+
+static tre_stack_t *
+tre_stack_new(int size, int max_size, int increment)
+{
+  tre_stack_t *s;
+
+  s = xmalloc(sizeof(*s));
+  if (s != NULL)
+    {
+      s->stack = xmalloc(sizeof(*s->stack) * size);
+      if (s->stack == NULL)
+	{
+	  xfree(s);
+	  return NULL;
+	}
+      s->size = size;
+      s->max_size = max_size;
+      s->increment = increment;
+      s->ptr = 0;
+    }
+  return s;
+}
+
+static void
+tre_stack_destroy(tre_stack_t *s)
+{
+  xfree(s->stack);
+  xfree(s);
+}
+
+static int
+tre_stack_num_objects(tre_stack_t *s)
+{
+  return s->ptr;
+}
+
+static reg_errcode_t
+tre_stack_push(tre_stack_t *s, union tre_stack_item value)
+{
+  if (s->ptr < s->size)
+    {
+      s->stack[s->ptr] = value;
+      s->ptr++;
+    }
+  else
+    {
+      if (s->size >= s->max_size)
+	{
+	  return REG_ESPACE;
+	}
+      else
+	{
+	  union tre_stack_item *new_buffer;
+	  int new_size;
+	  new_size = s->size + s->increment;
+	  if (new_size > s->max_size)
+	    new_size = s->max_size;
+	  new_buffer = xrealloc(s->stack, sizeof(*new_buffer) * new_size);
+	  if (new_buffer == NULL)
+	    {
+	      return REG_ESPACE;
+	    }
+	  assert(new_size > s->size);
+	  s->size = new_size;
+	  s->stack = new_buffer;
+	  tre_stack_push(s, value);
+	}
+    }
+  return REG_OK;
+}
+
+#define define_pushf(typetag, type)  \
+  declare_pushf(typetag, type) {     \
+    union tre_stack_item item;	     \
+    item.typetag ## _value = value;  \
+    return tre_stack_push(s, item);  \
+}
+
+define_pushf(int, int)
+define_pushf(voidptr, void *)
+
+#define define_popf(typetag, type)		    \
+  declare_popf(typetag, type) {			    \
+    return s->stack[--s->ptr].typetag ## _value;    \
+  }
+
+define_popf(int, int)
+define_popf(voidptr, void *)
+
+
+/***********************************************************************
+ from tre-parse.c and tre-parse.h
+***********************************************************************/
+
+/* Parse context. */
+typedef struct {
+	/* Memory allocator. The AST is allocated using this. */
+	tre_mem_t mem;
+	/* Stack used for keeping track of regexp syntax. */
+	tre_stack_t *stack;
+	/* The parsed node after a parse function returns. */
+	tre_ast_node_t *n;
+	/* Position in the regexp pattern after a parse function returns. */
+	const char *s;
+	/* The first character of the last subexpression parsed. */
+	const char *start;
+	/* Current submatch ID. */
+	int submatch_id;
+	/* Current position (number of literal). */
+	int position;
+	/* The highest back reference or -1 if none seen so far. */
+	int max_backref;
+	/* Compilation flags. */
+	int cflags;
+} tre_parse_ctx_t;
+
+/* Some macros for expanding \w, \s, etc. */
+static const struct {
+	char c;
+	const char *expansion;
+} tre_macros[] = {
+	{'t', "\t"}, {'n', "\n"}, {'r', "\r"},
+	{'f', "\f"}, {'a', "\a"}, {'e', "\033"},
+	{'w', "[[:alnum:]_]"}, {'W', "[^[:alnum:]_]"}, {'s', "[[:space:]]"},
+	{'S', "[^[:space:]]"}, {'d', "[[:digit:]]"}, {'D', "[^[:digit:]]"},
+	{ 0, 0 }
+};
+
+/* Expands a macro delimited by `regex' and `regex_end' to `buf', which
+   must have at least `len' items.  Sets buf[0] to zero if the there
+   is no match in `tre_macros'. */
+static const char *tre_expand_macro(const char *s)
+{
+	int i;
+	for (i = 0; tre_macros[i].c && tre_macros[i].c != *s; i++);
+	return tre_macros[i].expansion;
+}
+
+static int
+tre_compare_lit(const void *a, const void *b)
+{
+	const tre_literal_t *const *la = a;
+	const tre_literal_t *const *lb = b;
+	/* assumes the range of valid code_min is < INT_MAX */
+	return la[0]->code_min - lb[0]->code_min;
+}
+
+struct literals {
+	tre_mem_t mem;
+	tre_literal_t **a;
+	int len;
+	int cap;
+};
+
+static tre_literal_t *tre_new_lit(struct literals *p)
+{
+	tre_literal_t **a;
+	if (p->len >= p->cap) {
+		if (p->cap >= 1<<15)
+			return 0;
+		p->cap *= 2;
+		a = xrealloc(p->a, p->cap * sizeof *p->a);
+		if (!a)
+			return 0;
+		p->a = a;
+	}
+	a = p->a + p->len++;
+	*a = tre_mem_calloc(p->mem, sizeof **a);
+	return *a;
+}
+
+static int add_icase_literals(struct literals *ls, int min, int max)
+{
+	tre_literal_t *lit;
+	int b, e, c;
+	for (c=min; c<=max; ) {
+		/* assumes islower(c) and isupper(c) are exclusive
+		   and toupper(c)!=c if islower(c).
+		   multiple opposite case characters are not supported */
+		if (tre_islower(c)) {
+			b = e = tre_toupper(c);
+			for (c++, e++; c<=max; c++, e++)
+				if (tre_toupper(c) != e) break;
+		} else if (tre_isupper(c)) {
+			b = e = tre_tolower(c);
+			for (c++, e++; c<=max; c++, e++)
+				if (tre_tolower(c) != e) break;
+		} else {
+			c++;
+			continue;
+		}
+		lit = tre_new_lit(ls);
+		if (!lit)
+			return -1;
+		lit->code_min = b;
+		lit->code_max = e-1;
+		lit->position = -1;
+	}
+	return 0;
+}
+
+
+/* Maximum number of character classes in a negated bracket expression. */
+#define MAX_NEG_CLASSES 64
+
+struct neg {
+	int negate;
+	int len;
+	tre_ctype_t a[MAX_NEG_CLASSES];
+};
+
+// TODO: parse bracket into a set of non-overlapping [lo,hi] ranges
+
+/*
+bracket grammar:
+Bracket  =  '[' List ']'  |  '[^' List ']'
+List     =  Term  |  List Term
+Term     =  Char  |  Range  |  Chclass  |  Eqclass
+Range    =  Char '-' Char  |  Char '-' '-'
+Char     =  Coll  |  coll_single
+Meta     =  ']'  |  '-'
+Coll     =  '[.' coll_single '.]'  |  '[.' coll_multi '.]'  |  '[.' Meta '.]'
+Eqclass  =  '[=' coll_single '=]'  |  '[=' coll_multi '=]'
+Chclass  =  '[:' class ':]'
+
+coll_single is a single char collating element but it can be
+ '-' only at the beginning or end of a List and
+ ']' only at the beginning of a List and
+ '^' anywhere except after the openning '['
+*/
+
+static reg_errcode_t parse_bracket_terms(tre_parse_ctx_t *ctx, const char *s, struct literals *ls, struct neg *neg)
+{
+	const char *start = s;
+	tre_ctype_t class;
+	int min, max;
+	wchar_t wc;
+	int len;
+
+	for (;;) {
+		class = 0;
+		len = mbtowc(&wc, s, -1);
+		if (len <= 0)
+			return *s ? REG_BADPAT : REG_EBRACK;
+		if (*s == ']' && s != start) {
+			ctx->s = s+1;
+			return REG_OK;
+		}
+		if (*s == '-' && s != start && s[1] != ']' &&
+		    /* extension: [a-z--@] is accepted as [a-z]|[--@] */
+		    (s[1] != '-' || s[2] == ']'))
+			return REG_ERANGE;
+		if (*s == '[' && (s[1] == '.' || s[1] == '='))
+			/* collating symbols and equivalence classes are not supported */
+			return REG_ECOLLATE;
+		if (*s == '[' && s[1] == ':') {
+			char tmp[CHARCLASS_NAME_MAX+1];
+			s += 2;
+			for (len=0; len < CHARCLASS_NAME_MAX && s[len]; len++) {
+				if (s[len] == ':') {
+					memcpy(tmp, s, len);
+					tmp[len] = 0;
+					class = tre_ctype(tmp);
+					break;
+				}
+			}
+			if (!class || s[len+1] != ']')
+				return REG_ECTYPE;
+			min = 0;
+			max = TRE_CHAR_MAX;
+			s += len+2;
+		} else {
+			min = max = wc;
+			s += len;
+			if (*s == '-' && s[1] != ']') {
+				s++;
+				len = mbtowc(&wc, s, -1);
+				max = wc;
+				/* XXX - Should use collation order instead of
+				   encoding values in character ranges. */
+				if (len <= 0 || min > max)
+					return REG_ERANGE;
+				s += len;
+			}
+		}
+
+		if (class && neg->negate) {
+			if (neg->len >= MAX_NEG_CLASSES)
+				return REG_ESPACE;
+			neg->a[neg->len++] = class;
+		} else  {
+			tre_literal_t *lit = tre_new_lit(ls);
+			if (!lit)
+				return REG_ESPACE;
+			lit->code_min = min;
+			lit->code_max = max;
+			lit->class = class;
+			lit->position = -1;
+
+			/* Add opposite-case codepoints if REG_ICASE is present.
+			   It seems that POSIX requires that bracket negation
+			   should happen before case-folding, but most practical
+			   implementations do it the other way around. Changing
+			   the order would need efficient representation of
+			   case-fold ranges and bracket range sets even with
+			   simple patterns so this is ok for now. */
+			if (ctx->cflags & REG_ICASE && !class)
+				if (add_icase_literals(ls, min, max))
+					return REG_ESPACE;
+		}
+	}
+}
+
+static reg_errcode_t parse_bracket(tre_parse_ctx_t *ctx, const char *s)
+{
+	int i, max, min, negmax, negmin;
+	tre_ast_node_t *node = 0, *n;
+	tre_ctype_t *nc = 0;
+	tre_literal_t *lit;
+	struct literals ls;
+	struct neg neg;
+	reg_errcode_t err;
+
+	ls.mem = ctx->mem;
+	ls.len = 0;
+	ls.cap = 32;
+	ls.a = xmalloc(ls.cap * sizeof *ls.a);
+	if (!ls.a)
+		return REG_ESPACE;
+	neg.len = 0;
+	neg.negate = *s == '^';
+	if (neg.negate)
+		s++;
+
+	err = parse_bracket_terms(ctx, s, &ls, &neg);
+	if (err != REG_OK)
+		goto parse_bracket_done;
+
+	if (neg.negate) {
+		/*
+		 * With REG_NEWLINE, POSIX requires that newlines are not matched by
+		 * any form of a non-matching list.
+		 */
+		if (ctx->cflags & REG_NEWLINE) {
+			lit = tre_new_lit(&ls);
+			if (!lit) {
+				err = REG_ESPACE;
+				goto parse_bracket_done;
+			}
+			lit->code_min = '\n';
+			lit->code_max = '\n';
+			lit->position = -1;
+		}
+		/* Sort the array if we need to negate it. */
+		qsort(ls.a, ls.len, sizeof *ls.a, tre_compare_lit);
+		/* extra lit for the last negated range */
+		lit = tre_new_lit(&ls);
+		if (!lit) {
+			err = REG_ESPACE;
+			goto parse_bracket_done;
+		}
+		lit->code_min = TRE_CHAR_MAX+1;
+		lit->code_max = TRE_CHAR_MAX+1;
+		lit->position = -1;
+		/* negated classes */
+		if (neg.len) {
+			nc = tre_mem_alloc(ctx->mem, (neg.len+1)*sizeof *neg.a);
+			if (!nc) {
+				err = REG_ESPACE;
+				goto parse_bracket_done;
+			}
+			memcpy(nc, neg.a, neg.len*sizeof *neg.a);
+			nc[neg.len] = 0;
+		}
+	}
+
+	/* Build a union of the items in the array, negated if necessary. */
+	negmax = negmin = 0;
+	for (i = 0; i < ls.len; i++) {
+		lit = ls.a[i];
+		min = lit->code_min;
+		max = lit->code_max;
+		if (neg.negate) {
+			if (min <= negmin) {
+				/* Overlap. */
+				negmin = MAX(max + 1, negmin);
+				continue;
+			}
+			negmax = min - 1;
+			lit->code_min = negmin;
+			lit->code_max = negmax;
+			negmin = max + 1;
+		}
+		lit->position = ctx->position;
+		lit->neg_classes = nc;
+		n = tre_ast_new_node(ctx->mem, LITERAL, lit);
+		node = tre_ast_new_union(ctx->mem, node, n);
+		if (!node) {
+			err = REG_ESPACE;
+			break;
+		}
+	}
+
+parse_bracket_done:
+	xfree(ls.a);
+	ctx->position++;
+	ctx->n = node;
+	return err;
+}
+
+static const char *parse_dup_count(const char *s, int *n)
+{
+	*n = -1;
+	if (!isdigit(*s))
+		return s;
+	*n = 0;
+	for (;;) {
+		*n = 10 * *n + (*s - '0');
+		s++;
+		if (!isdigit(*s) || *n > RE_DUP_MAX)
+			break;
+	}
+	return s;
+}
+
+static const char *parse_dup(const char *s, int ere, int *pmin, int *pmax)
+{
+	int min, max;
+
+	s = parse_dup_count(s, &min);
+	if (*s == ',')
+		s = parse_dup_count(s+1, &max);
+	else
+		max = min;
+
+	if (
+		(max < min && max >= 0) ||
+		max > RE_DUP_MAX ||
+		min > RE_DUP_MAX ||
+		min < 0 ||
+		(!ere && *s++ != '\\') ||
+		*s++ != '}'
+	)
+		return 0;
+	*pmin = min;
+	*pmax = max;
+	return s;
+}
+
+static int hexval(unsigned c)
+{
+	if (c-'0'<10) return c-'0';
+	c |= 32;
+	if (c-'a'<6) return c-'a'+10;
+	return -1;
+}
+
+static reg_errcode_t marksub(tre_parse_ctx_t *ctx, tre_ast_node_t *node, int subid)
+{
+	if (node->submatch_id >= 0) {
+		tre_ast_node_t *n = tre_ast_new_literal(ctx->mem, EMPTY, -1, -1);
+		if (!n)
+			return REG_ESPACE;
+		n = tre_ast_new_catenation(ctx->mem, n, node);
+		if (!n)
+			return REG_ESPACE;
+		n->num_submatches = node->num_submatches;
+		node = n;
+	}
+	node->submatch_id = subid;
+	node->num_submatches++;
+	ctx->n = node;
+	return REG_OK;
+}
+
+/*
+BRE grammar:
+Regex  =  Branch  |  '^'  |  '$'  |  '^$'  |  '^' Branch  |  Branch '$'  |  '^' Branch '$'
+Branch =  Atom  |  Branch Atom
+Atom   =  char  |  quoted_char  |  '.'  |  Bracket  |  Atom Dup  |  '\(' Branch '\)'  |  back_ref
+Dup    =  '*'  |  '\{' Count '\}'  |  '\{' Count ',\}'  |  '\{' Count ',' Count '\}'
+
+(leading ^ and trailing $ in a sub expr may be an anchor or literal as well)
+
+ERE grammar:
+Regex  =  Branch  |  Regex '|' Branch
+Branch =  Atom  |  Branch Atom
+Atom   =  char  |  quoted_char  |  '.'  |  Bracket  |  Atom Dup  |  '(' Regex ')'  |  '^'  |  '$'
+Dup    =  '*'  |  '+'  |  '?'  |  '{' Count '}'  |  '{' Count ',}'  |  '{' Count ',' Count '}'
+
+(a*+?, ^*, $+, \X, {, (|a) are unspecified)
+*/
+
+static reg_errcode_t parse_atom(tre_parse_ctx_t *ctx, const char *s)
+{
+	int len, ere = ctx->cflags & REG_EXTENDED;
+	const char *p;
+	tre_ast_node_t *node;
+	wchar_t wc;
+	switch (*s) {
+	case '[':
+		return parse_bracket(ctx, s+1);
+	case '\\':
+		p = tre_expand_macro(s+1);
+		if (p) {
+			/* assume \X expansion is a single atom */
+			reg_errcode_t err = parse_atom(ctx, p);
+			ctx->s = s+2;
+			return err;
+		}
+		/* extensions: \b, \B, \<, \>, \xHH \x{HHHH} */
+		switch (*++s) {
+		case 0:
+			return REG_EESCAPE;
+		case 'b':
+			node = tre_ast_new_literal(ctx->mem, ASSERTION, ASSERT_AT_WB, -1);
+			break;
+		case 'B':
+			node = tre_ast_new_literal(ctx->mem, ASSERTION, ASSERT_AT_WB_NEG, -1);
+			break;
+		case '<':
+			node = tre_ast_new_literal(ctx->mem, ASSERTION, ASSERT_AT_BOW, -1);
+			break;
+		case '>':
+			node = tre_ast_new_literal(ctx->mem, ASSERTION, ASSERT_AT_EOW, -1);
+			break;
+		case 'x':
+			s++;
+			int i, v = 0, c;
+			len = 2;
+			if (*s == '{') {
+				len = 8;
+				s++;
+			}
+			for (i=0; i<len && v<0x110000; i++) {
+				c = hexval(s[i]);
+				if (c < 0) break;
+				v = 16*v + c;
+			}
+			s += i;
+			if (len == 8) {
+				if (*s != '}')
+					return REG_EBRACE;
+				s++;
+			}
+			node = tre_ast_new_literal(ctx->mem, v, v, ctx->position++);
+			s--;
+			break;
+		case '{':
+		case '+':
+		case '?':
+			/* extension: treat \+, \? as repetitions in BRE */
+			/* reject repetitions after empty expression in BRE */
+			if (!ere)
+				return REG_BADRPT;
+		case '|':
+			/* extension: treat \| as alternation in BRE */
+			if (!ere) {
+				node = tre_ast_new_literal(ctx->mem, EMPTY, -1, -1);
+				s--;
+				goto end;
+			}
+			/* fallthrough */
+		default:
+			if (!ere && (unsigned)*s-'1' < 9) {
+				/* back reference */
+				int val = *s - '0';
+				node = tre_ast_new_literal(ctx->mem, BACKREF, val, ctx->position++);
+				ctx->max_backref = MAX(val, ctx->max_backref);
+			} else {
+				/* extension: accept unknown escaped char
+				   as a literal */
+				goto parse_literal;
+			}
+		}
+		s++;
+		break;
+	case '.':
+		if (ctx->cflags & REG_NEWLINE) {
+			tre_ast_node_t *tmp1, *tmp2;
+			tmp1 = tre_ast_new_literal(ctx->mem, 0, '\n'-1, ctx->position++);
+			tmp2 = tre_ast_new_literal(ctx->mem, '\n'+1, TRE_CHAR_MAX, ctx->position++);
+			if (tmp1 && tmp2)
+				node = tre_ast_new_union(ctx->mem, tmp1, tmp2);
+			else
+				node = 0;
+		} else {
+			node = tre_ast_new_literal(ctx->mem, 0, TRE_CHAR_MAX, ctx->position++);
+		}
+		s++;
+		break;
+	case '^':
+		/* '^' has a special meaning everywhere in EREs, and at beginning of BRE. */
+		if (!ere && s != ctx->start)
+			goto parse_literal;
+		node = tre_ast_new_literal(ctx->mem, ASSERTION, ASSERT_AT_BOL, -1);
+		s++;
+		break;
+	case '$':
+		/* '$' is special everywhere in EREs, and at the end of a BRE subexpression. */
+		if (!ere && s[1] && (s[1]!='\\'|| (s[2]!=')' && s[2]!='|')))
+			goto parse_literal;
+		node = tre_ast_new_literal(ctx->mem, ASSERTION, ASSERT_AT_EOL, -1);
+		s++;
+		break;
+	case '*':
+	case '{':
+	case '+':
+	case '?':
+		/* reject repetitions after empty expression in ERE */
+		if (ere)
+			return REG_BADRPT;
+	case '|':
+		if (!ere)
+			goto parse_literal;
+	case 0:
+		node = tre_ast_new_literal(ctx->mem, EMPTY, -1, -1);
+		break;
+	default:
+parse_literal:
+		len = mbtowc(&wc, s, -1);
+		if (len < 0)
+			return REG_BADPAT;
+		if (ctx->cflags & REG_ICASE && (tre_isupper(wc) || tre_islower(wc))) {
+			tre_ast_node_t *tmp1, *tmp2;
+			/* multiple opposite case characters are not supported */
+			tmp1 = tre_ast_new_literal(ctx->mem, tre_toupper(wc), tre_toupper(wc), ctx->position);
+			tmp2 = tre_ast_new_literal(ctx->mem, tre_tolower(wc), tre_tolower(wc), ctx->position);
+			if (tmp1 && tmp2)
+				node = tre_ast_new_union(ctx->mem, tmp1, tmp2);
+			else
+				node = 0;
+		} else {
+			node = tre_ast_new_literal(ctx->mem, wc, wc, ctx->position);
+		}
+		ctx->position++;
+		s += len;
+		break;
+	}
+end:
+	if (!node)
+		return REG_ESPACE;
+	ctx->n = node;
+	ctx->s = s;
+	return REG_OK;
+}
+
+#define PUSHPTR(err, s, v) do { \
+	if ((err = tre_stack_push_voidptr(s, v)) != REG_OK) \
+		return err; \
+} while(0)
+
+#define PUSHINT(err, s, v) do { \
+	if ((err = tre_stack_push_int(s, v)) != REG_OK) \
+		return err; \
+} while(0)
+
+static reg_errcode_t tre_parse(tre_parse_ctx_t *ctx)
+{
+	tre_ast_node_t *nbranch=0, *nunion=0;
+	int ere = ctx->cflags & REG_EXTENDED;
+	const char *s = ctx->start;
+	int subid = 0;
+	int depth = 0;
+	reg_errcode_t err;
+	tre_stack_t *stack = ctx->stack;
+
+	PUSHINT(err, stack, subid++);
+	for (;;) {
+		if ((!ere && *s == '\\' && s[1] == '(') ||
+		    (ere && *s == '(')) {
+			PUSHPTR(err, stack, nunion);
+			PUSHPTR(err, stack, nbranch);
+			PUSHINT(err, stack, subid++);
+			s++;
+			if (!ere)
+				s++;
+			depth++;
+			nbranch = nunion = 0;
+			ctx->start = s;
+			continue;
+		}
+		if ((!ere && *s == '\\' && s[1] == ')') ||
+		    (ere && *s == ')' && depth)) {
+			ctx->n = tre_ast_new_literal(ctx->mem, EMPTY, -1, -1);
+			if (!ctx->n)
+				return REG_ESPACE;
+		} else {
+			err = parse_atom(ctx, s);
+			if (err != REG_OK)
+				return err;
+			s = ctx->s;
+		}
+
+	parse_iter:
+		for (;;) {
+			int min, max;
+
+			if (*s!='\\' && *s!='*') {
+				if (!ere)
+					break;
+				if (*s!='+' && *s!='?' && *s!='{')
+					break;
+			}
+			if (*s=='\\' && ere)
+				break;
+			/* extension: treat \+, \? as repetitions in BRE */
+			if (*s=='\\' && s[1]!='+' && s[1]!='?' && s[1]!='{')
+				break;
+			if (*s=='\\')
+				s++;
+
+			/* handle ^* at the start of a BRE. */
+			if (!ere && s==ctx->start+1 && s[-1]=='^')
+				break;
+
+			/* extension: multiple consecutive *+?{,} is unspecified,
+			   but (a+)+ has to be supported so accepting a++ makes
+			   sense, note however that the RE_DUP_MAX limit can be
+			   circumvented: (a{255}){255} uses a lot of memory.. */
+			if (*s=='{') {
+				s = parse_dup(s+1, ere, &min, &max);
+				if (!s)
+					return REG_BADBR;
+			} else {
+				min=0;
+				max=-1;
+				if (*s == '+')
+					min = 1;
+				if (*s == '?')
+					max = 1;
+				s++;
+			}
+			if (max == 0)
+				ctx->n = tre_ast_new_literal(ctx->mem, EMPTY, -1, -1);
+			else
+				ctx->n = tre_ast_new_iter(ctx->mem, ctx->n, min, max, 0);
+			if (!ctx->n)
+				return REG_ESPACE;
+		}
+
+		nbranch = tre_ast_new_catenation(ctx->mem, nbranch, ctx->n);
+		if ((ere && *s == '|') ||
+		    (ere && *s == ')' && depth) ||
+		    (!ere && *s == '\\' && s[1] == ')') ||
+		    /* extension: treat \| as alternation in BRE */
+		    (!ere && *s == '\\' && s[1] == '|') ||
+		    !*s) {
+			/* extension: empty branch is unspecified (), (|a), (a|)
+			   here they are not rejected but match on empty string */
+			int c = *s;
+			nunion = tre_ast_new_union(ctx->mem, nunion, nbranch);
+			nbranch = 0;
+
+			if (c == '\\' && s[1] == '|') {
+				s+=2;
+				ctx->start = s;
+			} else if (c == '|') {
+				s++;
+				ctx->start = s;
+			} else {
+				if (c == '\\') {
+					if (!depth) return REG_EPAREN;
+					s+=2;
+				} else if (c == ')')
+					s++;
+				depth--;
+				err = marksub(ctx, nunion, tre_stack_pop_int(stack));
+				if (err != REG_OK)
+					return err;
+				if (!c && depth<0) {
+					ctx->submatch_id = subid;
+					return REG_OK;
+				}
+				if (!c || depth<0)
+					return REG_EPAREN;
+				nbranch = tre_stack_pop_voidptr(stack);
+				nunion = tre_stack_pop_voidptr(stack);
+				goto parse_iter;
+			}
+		}
+	}
+}
+
+
+/***********************************************************************
+ from tre-compile.c
+***********************************************************************/
+
+
+/*
+  TODO:
+   - Fix tre_ast_to_tnfa() to recurse using a stack instead of recursive
+     function calls.
+*/
+
+/*
+  Algorithms to setup tags so that submatch addressing can be done.
+*/
+
+
+/* Inserts a catenation node to the root of the tree given in `node'.
+   As the left child a new tag with number `tag_id' to `node' is added,
+   and the right child is the old root. */
+static reg_errcode_t
+tre_add_tag_left(tre_mem_t mem, tre_ast_node_t *node, int tag_id)
+{
+  tre_catenation_t *c;
+
+  c = tre_mem_alloc(mem, sizeof(*c));
+  if (c == NULL)
+    return REG_ESPACE;
+  c->left = tre_ast_new_literal(mem, TAG, tag_id, -1);
+  if (c->left == NULL)
+    return REG_ESPACE;
+  c->right = tre_mem_alloc(mem, sizeof(tre_ast_node_t));
+  if (c->right == NULL)
+    return REG_ESPACE;
+
+  c->right->obj = node->obj;
+  c->right->type = node->type;
+  c->right->nullable = -1;
+  c->right->submatch_id = -1;
+  c->right->firstpos = NULL;
+  c->right->lastpos = NULL;
+  c->right->num_tags = 0;
+  c->right->num_submatches = 0;
+  node->obj = c;
+  node->type = CATENATION;
+  return REG_OK;
+}
+
+/* Inserts a catenation node to the root of the tree given in `node'.
+   As the right child a new tag with number `tag_id' to `node' is added,
+   and the left child is the old root. */
+static reg_errcode_t
+tre_add_tag_right(tre_mem_t mem, tre_ast_node_t *node, int tag_id)
+{
+  tre_catenation_t *c;
+
+  c = tre_mem_alloc(mem, sizeof(*c));
+  if (c == NULL)
+    return REG_ESPACE;
+  c->right = tre_ast_new_literal(mem, TAG, tag_id, -1);
+  if (c->right == NULL)
+    return REG_ESPACE;
+  c->left = tre_mem_alloc(mem, sizeof(tre_ast_node_t));
+  if (c->left == NULL)
+    return REG_ESPACE;
+
+  c->left->obj = node->obj;
+  c->left->type = node->type;
+  c->left->nullable = -1;
+  c->left->submatch_id = -1;
+  c->left->firstpos = NULL;
+  c->left->lastpos = NULL;
+  c->left->num_tags = 0;
+  c->left->num_submatches = 0;
+  node->obj = c;
+  node->type = CATENATION;
+  return REG_OK;
+}
+
+typedef enum {
+  ADDTAGS_RECURSE,
+  ADDTAGS_AFTER_ITERATION,
+  ADDTAGS_AFTER_UNION_LEFT,
+  ADDTAGS_AFTER_UNION_RIGHT,
+  ADDTAGS_AFTER_CAT_LEFT,
+  ADDTAGS_AFTER_CAT_RIGHT,
+  ADDTAGS_SET_SUBMATCH_END
+} tre_addtags_symbol_t;
+
+
+typedef struct {
+  int tag;
+  int next_tag;
+} tre_tag_states_t;
+
+
+/* Go through `regset' and set submatch data for submatches that are
+   using this tag. */
+static void
+tre_purge_regset(int *regset, tre_tnfa_t *tnfa, int tag)
+{
+  int i;
+
+  for (i = 0; regset[i] >= 0; i++)
+    {
+      int id = regset[i] / 2;
+      int start = !(regset[i] % 2);
+      if (start)
+	tnfa->submatch_data[id].so_tag = tag;
+      else
+	tnfa->submatch_data[id].eo_tag = tag;
+    }
+  regset[0] = -1;
+}
+
+
+/* Adds tags to appropriate locations in the parse tree in `tree', so that
+   subexpressions marked for submatch addressing can be traced. */
+static reg_errcode_t
+tre_add_tags(tre_mem_t mem, tre_stack_t *stack, tre_ast_node_t *tree,
+	     tre_tnfa_t *tnfa)
+{
+  reg_errcode_t status = REG_OK;
+  tre_addtags_symbol_t symbol;
+  tre_ast_node_t *node = tree; /* Tree node we are currently looking at. */
+  int bottom = tre_stack_num_objects(stack);
+  /* True for first pass (counting number of needed tags) */
+  int first_pass = (mem == NULL || tnfa == NULL);
+  int *regset, *orig_regset;
+  int num_tags = 0; /* Total number of tags. */
+  int num_minimals = 0;	 /* Number of special minimal tags. */
+  int tag = 0;	    /* The tag that is to be added next. */
+  int next_tag = 1; /* Next tag to use after this one. */
+  int *parents;	    /* Stack of submatches the current submatch is
+		       contained in. */
+  int minimal_tag = -1; /* Tag that marks the beginning of a minimal match. */
+  tre_tag_states_t *saved_states;
+
+  tre_tag_direction_t direction = TRE_TAG_MINIMIZE;
+  if (!first_pass)
+    {
+      tnfa->end_tag = 0;
+      tnfa->minimal_tags[0] = -1;
+    }
+
+  regset = xmalloc(sizeof(*regset) * ((tnfa->num_submatches + 1) * 2));
+  if (regset == NULL)
+    return REG_ESPACE;
+  regset[0] = -1;
+  orig_regset = regset;
+
+  parents = xmalloc(sizeof(*parents) * (tnfa->num_submatches + 1));
+  if (parents == NULL)
+    {
+      xfree(regset);
+      return REG_ESPACE;
+    }
+  parents[0] = -1;
+
+  saved_states = xmalloc(sizeof(*saved_states) * (tnfa->num_submatches + 1));
+  if (saved_states == NULL)
+    {
+      xfree(regset);
+      xfree(parents);
+      return REG_ESPACE;
+    }
+  else
+    {
+      unsigned int i;
+      for (i = 0; i <= tnfa->num_submatches; i++)
+	saved_states[i].tag = -1;
+    }
+
+  STACK_PUSH(stack, voidptr, node);
+  STACK_PUSH(stack, int, ADDTAGS_RECURSE);
+
+  while (tre_stack_num_objects(stack) > bottom)
+    {
+      if (status != REG_OK)
+	break;
+
+      symbol = (tre_addtags_symbol_t)tre_stack_pop_int(stack);
+      switch (symbol)
+	{
+
+	case ADDTAGS_SET_SUBMATCH_END:
+	  {
+	    int id = tre_stack_pop_int(stack);
+	    int i;
+
+	    /* Add end of this submatch to regset. */
+	    for (i = 0; regset[i] >= 0; i++);
+	    regset[i] = id * 2 + 1;
+	    regset[i + 1] = -1;
+
+	    /* Pop this submatch from the parents stack. */
+	    for (i = 0; parents[i] >= 0; i++);
+	    parents[i - 1] = -1;
+	    break;
+	  }
+
+	case ADDTAGS_RECURSE:
+	  node = tre_stack_pop_voidptr(stack);
+
+	  if (node->submatch_id >= 0)
+	    {
+	      int id = node->submatch_id;
+	      int i;
+
+
+	      /* Add start of this submatch to regset. */
+	      for (i = 0; regset[i] >= 0; i++);
+	      regset[i] = id * 2;
+	      regset[i + 1] = -1;
+
+	      if (!first_pass)
+		{
+		  for (i = 0; parents[i] >= 0; i++);
+		  tnfa->submatch_data[id].parents = NULL;
+		  if (i > 0)
+		    {
+		      int *p = xmalloc(sizeof(*p) * (i + 1));
+		      if (p == NULL)
+			{
+			  status = REG_ESPACE;
+			  break;
+			}
+		      assert(tnfa->submatch_data[id].parents == NULL);
+		      tnfa->submatch_data[id].parents = p;
+		      for (i = 0; parents[i] >= 0; i++)
+			p[i] = parents[i];
+		      p[i] = -1;
+		    }
+		}
+
+	      /* Add end of this submatch to regset after processing this
+		 node. */
+	      STACK_PUSHX(stack, int, node->submatch_id);
+	      STACK_PUSHX(stack, int, ADDTAGS_SET_SUBMATCH_END);
+	    }
+
+	  switch (node->type)
+	    {
+	    case LITERAL:
+	      {
+		tre_literal_t *lit = node->obj;
+
+		if (!IS_SPECIAL(lit) || IS_BACKREF(lit))
+		  {
+		    int i;
+		    if (regset[0] >= 0)
+		      {
+			/* Regset is not empty, so add a tag before the
+			   literal or backref. */
+			if (!first_pass)
+			  {
+			    status = tre_add_tag_left(mem, node, tag);
+			    tnfa->tag_directions[tag] = direction;
+			    if (minimal_tag >= 0)
+			      {
+				for (i = 0; tnfa->minimal_tags[i] >= 0; i++);
+				tnfa->minimal_tags[i] = tag;
+				tnfa->minimal_tags[i + 1] = minimal_tag;
+				tnfa->minimal_tags[i + 2] = -1;
+				minimal_tag = -1;
+				num_minimals++;
+			      }
+			    tre_purge_regset(regset, tnfa, tag);
+			  }
+			else
+			  {
+			    node->num_tags = 1;
+			  }
+
+			regset[0] = -1;
+			tag = next_tag;
+			num_tags++;
+			next_tag++;
+		      }
+		  }
+		else
+		  {
+		    assert(!IS_TAG(lit));
+		  }
+		break;
+	      }
+	    case CATENATION:
+	      {
+		tre_catenation_t *cat = node->obj;
+		tre_ast_node_t *left = cat->left;
+		tre_ast_node_t *right = cat->right;
+		int reserved_tag = -1;
+
+
+		/* After processing right child. */
+		STACK_PUSHX(stack, voidptr, node);
+		STACK_PUSHX(stack, int, ADDTAGS_AFTER_CAT_RIGHT);
+
+		/* Process right child. */
+		STACK_PUSHX(stack, voidptr, right);
+		STACK_PUSHX(stack, int, ADDTAGS_RECURSE);
+
+		/* After processing left child. */
+		STACK_PUSHX(stack, int, next_tag + left->num_tags);
+		if (left->num_tags > 0 && right->num_tags > 0)
+		  {
+		    /* Reserve the next tag to the right child. */
+		    reserved_tag = next_tag;
+		    next_tag++;
+		  }
+		STACK_PUSHX(stack, int, reserved_tag);
+		STACK_PUSHX(stack, int, ADDTAGS_AFTER_CAT_LEFT);
+
+		/* Process left child. */
+		STACK_PUSHX(stack, voidptr, left);
+		STACK_PUSHX(stack, int, ADDTAGS_RECURSE);
+
+		}
+	      break;
+	    case ITERATION:
+	      {
+		tre_iteration_t *iter = node->obj;
+
+		if (first_pass)
+		  {
+		    STACK_PUSHX(stack, int, regset[0] >= 0 || iter->minimal);
+		  }
+		else
+		  {
+		    STACK_PUSHX(stack, int, tag);
+		    STACK_PUSHX(stack, int, iter->minimal);
+		  }
+		STACK_PUSHX(stack, voidptr, node);
+		STACK_PUSHX(stack, int, ADDTAGS_AFTER_ITERATION);
+
+		STACK_PUSHX(stack, voidptr, iter->arg);
+		STACK_PUSHX(stack, int, ADDTAGS_RECURSE);
+
+		/* Regset is not empty, so add a tag here. */
+		if (regset[0] >= 0 || iter->minimal)
+		  {
+		    if (!first_pass)
+		      {
+			int i;
+			status = tre_add_tag_left(mem, node, tag);
+			if (iter->minimal)
+			  tnfa->tag_directions[tag] = TRE_TAG_MAXIMIZE;
+			else
+			  tnfa->tag_directions[tag] = direction;
+			if (minimal_tag >= 0)
+			  {
+			    for (i = 0; tnfa->minimal_tags[i] >= 0; i++);
+			    tnfa->minimal_tags[i] = tag;
+			    tnfa->minimal_tags[i + 1] = minimal_tag;
+			    tnfa->minimal_tags[i + 2] = -1;
+			    minimal_tag = -1;
+			    num_minimals++;
+			  }
+			tre_purge_regset(regset, tnfa, tag);
+		      }
+
+		    regset[0] = -1;
+		    tag = next_tag;
+		    num_tags++;
+		    next_tag++;
+		  }
+		direction = TRE_TAG_MINIMIZE;
+	      }
+	      break;
+	    case UNION:
+	      {
+		tre_union_t *uni = node->obj;
+		tre_ast_node_t *left = uni->left;
+		tre_ast_node_t *right = uni->right;
+		int left_tag;
+		int right_tag;
+
+		if (regset[0] >= 0)
+		  {
+		    left_tag = next_tag;
+		    right_tag = next_tag + 1;
+		  }
+		else
+		  {
+		    left_tag = tag;
+		    right_tag = next_tag;
+		  }
+
+		/* After processing right child. */
+		STACK_PUSHX(stack, int, right_tag);
+		STACK_PUSHX(stack, int, left_tag);
+		STACK_PUSHX(stack, voidptr, regset);
+		STACK_PUSHX(stack, int, regset[0] >= 0);
+		STACK_PUSHX(stack, voidptr, node);
+		STACK_PUSHX(stack, voidptr, right);
+		STACK_PUSHX(stack, voidptr, left);
+		STACK_PUSHX(stack, int, ADDTAGS_AFTER_UNION_RIGHT);
+
+		/* Process right child. */
+		STACK_PUSHX(stack, voidptr, right);
+		STACK_PUSHX(stack, int, ADDTAGS_RECURSE);
+
+		/* After processing left child. */
+		STACK_PUSHX(stack, int, ADDTAGS_AFTER_UNION_LEFT);
+
+		/* Process left child. */
+		STACK_PUSHX(stack, voidptr, left);
+		STACK_PUSHX(stack, int, ADDTAGS_RECURSE);
+
+		/* Regset is not empty, so add a tag here. */
+		if (regset[0] >= 0)
+		  {
+		    if (!first_pass)
+		      {
+			int i;
+			status = tre_add_tag_left(mem, node, tag);
+			tnfa->tag_directions[tag] = direction;
+			if (minimal_tag >= 0)
+			  {
+			    for (i = 0; tnfa->minimal_tags[i] >= 0; i++);
+			    tnfa->minimal_tags[i] = tag;
+			    tnfa->minimal_tags[i + 1] = minimal_tag;
+			    tnfa->minimal_tags[i + 2] = -1;
+			    minimal_tag = -1;
+			    num_minimals++;
+			  }
+			tre_purge_regset(regset, tnfa, tag);
+		      }
+
+		    regset[0] = -1;
+		    tag = next_tag;
+		    num_tags++;
+		    next_tag++;
+		  }
+
+		if (node->num_submatches > 0)
+		  {
+		    /* The next two tags are reserved for markers. */
+		    next_tag++;
+		    tag = next_tag;
+		    next_tag++;
+		  }
+
+		break;
+	      }
+	    }
+
+	  if (node->submatch_id >= 0)
+	    {
+	      int i;
+	      /* Push this submatch on the parents stack. */
+	      for (i = 0; parents[i] >= 0; i++);
+	      parents[i] = node->submatch_id;
+	      parents[i + 1] = -1;
+	    }
+
+	  break; /* end case: ADDTAGS_RECURSE */
+
+	case ADDTAGS_AFTER_ITERATION:
+	  {
+	    int minimal = 0;
+	    int enter_tag;
+	    node = tre_stack_pop_voidptr(stack);
+	    if (first_pass)
+	      {
+		node->num_tags = ((tre_iteration_t *)node->obj)->arg->num_tags
+		  + tre_stack_pop_int(stack);
+		minimal_tag = -1;
+	      }
+	    else
+	      {
+		minimal = tre_stack_pop_int(stack);
+		enter_tag = tre_stack_pop_int(stack);
+		if (minimal)
+		  minimal_tag = enter_tag;
+	      }
+
+	    if (!first_pass)
+	      {
+		if (minimal)
+		  direction = TRE_TAG_MINIMIZE;
+		else
+		  direction = TRE_TAG_MAXIMIZE;
+	      }
+	    break;
+	  }
+
+	case ADDTAGS_AFTER_CAT_LEFT:
+	  {
+	    int new_tag = tre_stack_pop_int(stack);
+	    next_tag = tre_stack_pop_int(stack);
+	    if (new_tag >= 0)
+	      {
+		tag = new_tag;
+	      }
+	    break;
+	  }
+
+	case ADDTAGS_AFTER_CAT_RIGHT:
+	  node = tre_stack_pop_voidptr(stack);
+	  if (first_pass)
+	    node->num_tags = ((tre_catenation_t *)node->obj)->left->num_tags
+	      + ((tre_catenation_t *)node->obj)->right->num_tags;
+	  break;
+
+	case ADDTAGS_AFTER_UNION_LEFT:
+	  /* Lift the bottom of the `regset' array so that when processing
+	     the right operand the items currently in the array are
+	     invisible.	 The original bottom was saved at ADDTAGS_UNION and
+	     will be restored at ADDTAGS_AFTER_UNION_RIGHT below. */
+	  while (*regset >= 0)
+	    regset++;
+	  break;
+
+	case ADDTAGS_AFTER_UNION_RIGHT:
+	  {
+	    int added_tags, tag_left, tag_right;
+	    tre_ast_node_t *left = tre_stack_pop_voidptr(stack);
+	    tre_ast_node_t *right = tre_stack_pop_voidptr(stack);
+	    node = tre_stack_pop_voidptr(stack);
+	    added_tags = tre_stack_pop_int(stack);
+	    if (first_pass)
+	      {
+		node->num_tags = ((tre_union_t *)node->obj)->left->num_tags
+		  + ((tre_union_t *)node->obj)->right->num_tags + added_tags
+		  + ((node->num_submatches > 0) ? 2 : 0);
+	      }
+	    regset = tre_stack_pop_voidptr(stack);
+	    tag_left = tre_stack_pop_int(stack);
+	    tag_right = tre_stack_pop_int(stack);
+
+	    /* Add tags after both children, the left child gets a smaller
+	       tag than the right child.  This guarantees that we prefer
+	       the left child over the right child. */
+	    /* XXX - This is not always necessary (if the children have
+	       tags which must be seen for every match of that child). */
+	    /* XXX - Check if this is the only place where tre_add_tag_right
+	       is used.	 If so, use tre_add_tag_left (putting the tag before
+	       the child as opposed after the child) and throw away
+	       tre_add_tag_right. */
+	    if (node->num_submatches > 0)
+	      {
+		if (!first_pass)
+		  {
+		    status = tre_add_tag_right(mem, left, tag_left);
+		    tnfa->tag_directions[tag_left] = TRE_TAG_MAXIMIZE;
+		    if (status == REG_OK)
+		      status = tre_add_tag_right(mem, right, tag_right);
+		    tnfa->tag_directions[tag_right] = TRE_TAG_MAXIMIZE;
+		  }
+		num_tags += 2;
+	      }
+	    direction = TRE_TAG_MAXIMIZE;
+	    break;
+	  }
+
+	default:
+	  assert(0);
+	  break;
+
+	} /* end switch(symbol) */
+    } /* end while(tre_stack_num_objects(stack) > bottom) */
+
+  if (!first_pass)
+    tre_purge_regset(regset, tnfa, tag);
+
+  if (!first_pass && minimal_tag >= 0)
+    {
+      int i;
+      for (i = 0; tnfa->minimal_tags[i] >= 0; i++);
+      tnfa->minimal_tags[i] = tag;
+      tnfa->minimal_tags[i + 1] = minimal_tag;
+      tnfa->minimal_tags[i + 2] = -1;
+      minimal_tag = -1;
+      num_minimals++;
+    }
+
+  assert(tree->num_tags == num_tags);
+  tnfa->end_tag = num_tags;
+  tnfa->num_tags = num_tags;
+  tnfa->num_minimals = num_minimals;
+  xfree(orig_regset);
+  xfree(parents);
+  xfree(saved_states);
+  return status;
+}
+
+
+
+/*
+  AST to TNFA compilation routines.
+*/
+
+typedef enum {
+  COPY_RECURSE,
+  COPY_SET_RESULT_PTR
+} tre_copyast_symbol_t;
+
+/* Flags for tre_copy_ast(). */
+#define COPY_REMOVE_TAGS	 1
+#define COPY_MAXIMIZE_FIRST_TAG	 2
+
+static reg_errcode_t
+tre_copy_ast(tre_mem_t mem, tre_stack_t *stack, tre_ast_node_t *ast,
+	     int flags, int *pos_add, tre_tag_direction_t *tag_directions,
+	     tre_ast_node_t **copy, int *max_pos)
+{
+  reg_errcode_t status = REG_OK;
+  int bottom = tre_stack_num_objects(stack);
+  int num_copied = 0;
+  int first_tag = 1;
+  tre_ast_node_t **result = copy;
+  tre_copyast_symbol_t symbol;
+
+  STACK_PUSH(stack, voidptr, ast);
+  STACK_PUSH(stack, int, COPY_RECURSE);
+
+  while (status == REG_OK && tre_stack_num_objects(stack) > bottom)
+    {
+      tre_ast_node_t *node;
+      if (status != REG_OK)
+	break;
+
+      symbol = (tre_copyast_symbol_t)tre_stack_pop_int(stack);
+      switch (symbol)
+	{
+	case COPY_SET_RESULT_PTR:
+	  result = tre_stack_pop_voidptr(stack);
+	  break;
+	case COPY_RECURSE:
+	  node = tre_stack_pop_voidptr(stack);
+	  switch (node->type)
+	    {
+	    case LITERAL:
+	      {
+		tre_literal_t *lit = node->obj;
+		int pos = lit->position;
+		int min = lit->code_min;
+		int max = lit->code_max;
+		if (!IS_SPECIAL(lit) || IS_BACKREF(lit))
+		  {
+		    /* XXX - e.g. [ab] has only one position but two
+		       nodes, so we are creating holes in the state space
+		       here.  Not fatal, just wastes memory. */
+		    pos += *pos_add;
+		    num_copied++;
+		  }
+		else if (IS_TAG(lit) && (flags & COPY_REMOVE_TAGS))
+		  {
+		    /* Change this tag to empty. */
+		    min = EMPTY;
+		    max = pos = -1;
+		  }
+		else if (IS_TAG(lit) && (flags & COPY_MAXIMIZE_FIRST_TAG)
+			 && first_tag)
+		  {
+		    /* Maximize the first tag. */
+		    tag_directions[max] = TRE_TAG_MAXIMIZE;
+		    first_tag = 0;
+		  }
+		*result = tre_ast_new_literal(mem, min, max, pos);
+		if (*result == NULL)
+		  status = REG_ESPACE;
+		else {
+		  tre_literal_t *p = (*result)->obj;
+		  p->class = lit->class;
+		  p->neg_classes = lit->neg_classes;
+		}
+
+		if (pos > *max_pos)
+		  *max_pos = pos;
+		break;
+	      }
+	    case UNION:
+	      {
+		tre_union_t *uni = node->obj;
+		tre_union_t *tmp;
+		*result = tre_ast_new_union(mem, uni->left, uni->right);
+		if (*result == NULL)
+		  {
+		    status = REG_ESPACE;
+		    break;
+		  }
+		tmp = (*result)->obj;
+		result = &tmp->left;
+		STACK_PUSHX(stack, voidptr, uni->right);
+		STACK_PUSHX(stack, int, COPY_RECURSE);
+		STACK_PUSHX(stack, voidptr, &tmp->right);
+		STACK_PUSHX(stack, int, COPY_SET_RESULT_PTR);
+		STACK_PUSHX(stack, voidptr, uni->left);
+		STACK_PUSHX(stack, int, COPY_RECURSE);
+		break;
+	      }
+	    case CATENATION:
+	      {
+		tre_catenation_t *cat = node->obj;
+		tre_catenation_t *tmp;
+		*result = tre_ast_new_catenation(mem, cat->left, cat->right);
+		if (*result == NULL)
+		  {
+		    status = REG_ESPACE;
+		    break;
+		  }
+		tmp = (*result)->obj;
+		tmp->left = NULL;
+		tmp->right = NULL;
+		result = &tmp->left;
+
+		STACK_PUSHX(stack, voidptr, cat->right);
+		STACK_PUSHX(stack, int, COPY_RECURSE);
+		STACK_PUSHX(stack, voidptr, &tmp->right);
+		STACK_PUSHX(stack, int, COPY_SET_RESULT_PTR);
+		STACK_PUSHX(stack, voidptr, cat->left);
+		STACK_PUSHX(stack, int, COPY_RECURSE);
+		break;
+	      }
+	    case ITERATION:
+	      {
+		tre_iteration_t *iter = node->obj;
+		STACK_PUSHX(stack, voidptr, iter->arg);
+		STACK_PUSHX(stack, int, COPY_RECURSE);
+		*result = tre_ast_new_iter(mem, iter->arg, iter->min,
+					   iter->max, iter->minimal);
+		if (*result == NULL)
+		  {
+		    status = REG_ESPACE;
+		    break;
+		  }
+		iter = (*result)->obj;
+		result = &iter->arg;
+		break;
+	      }
+	    default:
+	      assert(0);
+	      break;
+	    }
+	  break;
+	}
+    }
+  *pos_add += num_copied;
+  return status;
+}
+
+typedef enum {
+  EXPAND_RECURSE,
+  EXPAND_AFTER_ITER
+} tre_expand_ast_symbol_t;
+
+/* Expands each iteration node that has a finite nonzero minimum or maximum
+   iteration count to a catenated sequence of copies of the node. */
+static reg_errcode_t
+tre_expand_ast(tre_mem_t mem, tre_stack_t *stack, tre_ast_node_t *ast,
+	       int *position, tre_tag_direction_t *tag_directions)
+{
+  reg_errcode_t status = REG_OK;
+  int bottom = tre_stack_num_objects(stack);
+  int pos_add = 0;
+  int pos_add_total = 0;
+  int max_pos = 0;
+  int iter_depth = 0;
+
+  STACK_PUSHR(stack, voidptr, ast);
+  STACK_PUSHR(stack, int, EXPAND_RECURSE);
+  while (status == REG_OK && tre_stack_num_objects(stack) > bottom)
+    {
+      tre_ast_node_t *node;
+      tre_expand_ast_symbol_t symbol;
+
+      if (status != REG_OK)
+	break;
+
+      symbol = (tre_expand_ast_symbol_t)tre_stack_pop_int(stack);
+      node = tre_stack_pop_voidptr(stack);
+      switch (symbol)
+	{
+	case EXPAND_RECURSE:
+	  switch (node->type)
+	    {
+	    case LITERAL:
+	      {
+		tre_literal_t *lit= node->obj;
+		if (!IS_SPECIAL(lit) || IS_BACKREF(lit))
+		  {
+		    lit->position += pos_add;
+		    if (lit->position > max_pos)
+		      max_pos = lit->position;
+		  }
+		break;
+	      }
+	    case UNION:
+	      {
+		tre_union_t *uni = node->obj;
+		STACK_PUSHX(stack, voidptr, uni->right);
+		STACK_PUSHX(stack, int, EXPAND_RECURSE);
+		STACK_PUSHX(stack, voidptr, uni->left);
+		STACK_PUSHX(stack, int, EXPAND_RECURSE);
+		break;
+	      }
+	    case CATENATION:
+	      {
+		tre_catenation_t *cat = node->obj;
+		STACK_PUSHX(stack, voidptr, cat->right);
+		STACK_PUSHX(stack, int, EXPAND_RECURSE);
+		STACK_PUSHX(stack, voidptr, cat->left);
+		STACK_PUSHX(stack, int, EXPAND_RECURSE);
+		break;
+	      }
+	    case ITERATION:
+	      {
+		tre_iteration_t *iter = node->obj;
+		STACK_PUSHX(stack, int, pos_add);
+		STACK_PUSHX(stack, voidptr, node);
+		STACK_PUSHX(stack, int, EXPAND_AFTER_ITER);
+		STACK_PUSHX(stack, voidptr, iter->arg);
+		STACK_PUSHX(stack, int, EXPAND_RECURSE);
+		/* If we are going to expand this node at EXPAND_AFTER_ITER
+		   then don't increase the `pos' fields of the nodes now, it
+		   will get done when expanding. */
+		if (iter->min > 1 || iter->max > 1)
+		  pos_add = 0;
+		iter_depth++;
+		break;
+	      }
+	    default:
+	      assert(0);
+	      break;
+	    }
+	  break;
+	case EXPAND_AFTER_ITER:
+	  {
+	    tre_iteration_t *iter = node->obj;
+	    int pos_add_last;
+	    pos_add = tre_stack_pop_int(stack);
+	    pos_add_last = pos_add;
+	    if (iter->min > 1 || iter->max > 1)
+	      {
+		tre_ast_node_t *seq1 = NULL, *seq2 = NULL;
+		int j;
+		int pos_add_save = pos_add;
+
+		/* Create a catenated sequence of copies of the node. */
+		for (j = 0; j < iter->min; j++)
+		  {
+		    tre_ast_node_t *copy;
+		    /* Remove tags from all but the last copy. */
+		    int flags = ((j + 1 < iter->min)
+				 ? COPY_REMOVE_TAGS
+				 : COPY_MAXIMIZE_FIRST_TAG);
+		    pos_add_save = pos_add;
+		    status = tre_copy_ast(mem, stack, iter->arg, flags,
+					  &pos_add, tag_directions, &copy,
+					  &max_pos);
+		    if (status != REG_OK)
+		      return status;
+		    if (seq1 != NULL)
+		      seq1 = tre_ast_new_catenation(mem, seq1, copy);
+		    else
+		      seq1 = copy;
+		    if (seq1 == NULL)
+		      return REG_ESPACE;
+		  }
+
+		if (iter->max == -1)
+		  {
+		    /* No upper limit. */
+		    pos_add_save = pos_add;
+		    status = tre_copy_ast(mem, stack, iter->arg, 0,
+					  &pos_add, NULL, &seq2, &max_pos);
+		    if (status != REG_OK)
+		      return status;
+		    seq2 = tre_ast_new_iter(mem, seq2, 0, -1, 0);
+		    if (seq2 == NULL)
+		      return REG_ESPACE;
+		  }
+		else
+		  {
+		    for (j = iter->min; j < iter->max; j++)
+		      {
+			tre_ast_node_t *tmp, *copy;
+			pos_add_save = pos_add;
+			status = tre_copy_ast(mem, stack, iter->arg, 0,
+					      &pos_add, NULL, &copy, &max_pos);
+			if (status != REG_OK)
+			  return status;
+			if (seq2 != NULL)
+			  seq2 = tre_ast_new_catenation(mem, copy, seq2);
+			else
+			  seq2 = copy;
+			if (seq2 == NULL)
+			  return REG_ESPACE;
+			tmp = tre_ast_new_literal(mem, EMPTY, -1, -1);
+			if (tmp == NULL)
+			  return REG_ESPACE;
+			seq2 = tre_ast_new_union(mem, tmp, seq2);
+			if (seq2 == NULL)
+			  return REG_ESPACE;
+		      }
+		  }
+
+		pos_add = pos_add_save;
+		if (seq1 == NULL)
+		  seq1 = seq2;
+		else if (seq2 != NULL)
+		  seq1 = tre_ast_new_catenation(mem, seq1, seq2);
+		if (seq1 == NULL)
+		  return REG_ESPACE;
+		node->obj = seq1->obj;
+		node->type = seq1->type;
+	      }
+
+	    iter_depth--;
+	    pos_add_total += pos_add - pos_add_last;
+	    if (iter_depth == 0)
+	      pos_add = pos_add_total;
+
+	    break;
+	  }
+	default:
+	  assert(0);
+	  break;
+	}
+    }
+
+  *position += pos_add_total;
+
+  /* `max_pos' should never be larger than `*position' if the above
+     code works, but just an extra safeguard let's make sure
+     `*position' is set large enough so enough memory will be
+     allocated for the transition table. */
+  if (max_pos > *position)
+    *position = max_pos;
+
+  return status;
+}
+
+static tre_pos_and_tags_t *
+tre_set_empty(tre_mem_t mem)
+{
+  tre_pos_and_tags_t *new_set;
+
+  new_set = tre_mem_calloc(mem, sizeof(*new_set));
+  if (new_set == NULL)
+    return NULL;
+
+  new_set[0].position = -1;
+  new_set[0].code_min = -1;
+  new_set[0].code_max = -1;
+
+  return new_set;
+}
+
+static tre_pos_and_tags_t *
+tre_set_one(tre_mem_t mem, int position, int code_min, int code_max,
+	    tre_ctype_t class, tre_ctype_t *neg_classes, int backref)
+{
+  tre_pos_and_tags_t *new_set;
+
+  new_set = tre_mem_calloc(mem, sizeof(*new_set) * 2);
+  if (new_set == NULL)
+    return NULL;
+
+  new_set[0].position = position;
+  new_set[0].code_min = code_min;
+  new_set[0].code_max = code_max;
+  new_set[0].class = class;
+  new_set[0].neg_classes = neg_classes;
+  new_set[0].backref = backref;
+  new_set[1].position = -1;
+  new_set[1].code_min = -1;
+  new_set[1].code_max = -1;
+
+  return new_set;
+}
+
+static tre_pos_and_tags_t *
+tre_set_union(tre_mem_t mem, tre_pos_and_tags_t *set1, tre_pos_and_tags_t *set2,
+	      int *tags, int assertions)
+{
+  int s1, s2, i, j;
+  tre_pos_and_tags_t *new_set;
+  int *new_tags;
+  int num_tags;
+
+  for (num_tags = 0; tags != NULL && tags[num_tags] >= 0; num_tags++);
+  for (s1 = 0; set1[s1].position >= 0; s1++);
+  for (s2 = 0; set2[s2].position >= 0; s2++);
+  new_set = tre_mem_calloc(mem, sizeof(*new_set) * (s1 + s2 + 1));
+  if (!new_set )
+    return NULL;
+
+  for (s1 = 0; set1[s1].position >= 0; s1++)
+    {
+      new_set[s1].position = set1[s1].position;
+      new_set[s1].code_min = set1[s1].code_min;
+      new_set[s1].code_max = set1[s1].code_max;
+      new_set[s1].assertions = set1[s1].assertions | assertions;
+      new_set[s1].class = set1[s1].class;
+      new_set[s1].neg_classes = set1[s1].neg_classes;
+      new_set[s1].backref = set1[s1].backref;
+      if (set1[s1].tags == NULL && tags == NULL)
+	new_set[s1].tags = NULL;
+      else
+	{
+	  for (i = 0; set1[s1].tags != NULL && set1[s1].tags[i] >= 0; i++);
+	  new_tags = tre_mem_alloc(mem, (sizeof(*new_tags)
+					 * (i + num_tags + 1)));
+	  if (new_tags == NULL)
+	    return NULL;
+	  for (j = 0; j < i; j++)
+	    new_tags[j] = set1[s1].tags[j];
+	  for (i = 0; i < num_tags; i++)
+	    new_tags[j + i] = tags[i];
+	  new_tags[j + i] = -1;
+	  new_set[s1].tags = new_tags;
+	}
+    }
+
+  for (s2 = 0; set2[s2].position >= 0; s2++)
+    {
+      new_set[s1 + s2].position = set2[s2].position;
+      new_set[s1 + s2].code_min = set2[s2].code_min;
+      new_set[s1 + s2].code_max = set2[s2].code_max;
+      /* XXX - why not | assertions here as well? */
+      new_set[s1 + s2].assertions = set2[s2].assertions;
+      new_set[s1 + s2].class = set2[s2].class;
+      new_set[s1 + s2].neg_classes = set2[s2].neg_classes;
+      new_set[s1 + s2].backref = set2[s2].backref;
+      if (set2[s2].tags == NULL)
+	new_set[s1 + s2].tags = NULL;
+      else
+	{
+	  for (i = 0; set2[s2].tags[i] >= 0; i++);
+	  new_tags = tre_mem_alloc(mem, sizeof(*new_tags) * (i + 1));
+	  if (new_tags == NULL)
+	    return NULL;
+	  for (j = 0; j < i; j++)
+	    new_tags[j] = set2[s2].tags[j];
+	  new_tags[j] = -1;
+	  new_set[s1 + s2].tags = new_tags;
+	}
+    }
+  new_set[s1 + s2].position = -1;
+  return new_set;
+}
+
+/* Finds the empty path through `node' which is the one that should be
+   taken according to POSIX.2 rules, and adds the tags on that path to
+   `tags'.   `tags' may be NULL.  If `num_tags_seen' is not NULL, it is
+   set to the number of tags seen on the path. */
+static reg_errcode_t
+tre_match_empty(tre_stack_t *stack, tre_ast_node_t *node, int *tags,
+		int *assertions, int *num_tags_seen)
+{
+  tre_literal_t *lit;
+  tre_union_t *uni;
+  tre_catenation_t *cat;
+  tre_iteration_t *iter;
+  int i;
+  int bottom = tre_stack_num_objects(stack);
+  reg_errcode_t status = REG_OK;
+  if (num_tags_seen)
+    *num_tags_seen = 0;
+
+  status = tre_stack_push_voidptr(stack, node);
+
+  /* Walk through the tree recursively. */
+  while (status == REG_OK && tre_stack_num_objects(stack) > bottom)
+    {
+      node = tre_stack_pop_voidptr(stack);
+
+      switch (node->type)
+	{
+	case LITERAL:
+	  lit = (tre_literal_t *)node->obj;
+	  switch (lit->code_min)
+	    {
+	    case TAG:
+	      if (lit->code_max >= 0)
+		{
+		  if (tags != NULL)
+		    {
+		      /* Add the tag to `tags'. */
+		      for (i = 0; tags[i] >= 0; i++)
+			if (tags[i] == lit->code_max)
+			  break;
+		      if (tags[i] < 0)
+			{
+			  tags[i] = lit->code_max;
+			  tags[i + 1] = -1;
+			}
+		    }
+		  if (num_tags_seen)
+		    (*num_tags_seen)++;
+		}
+	      break;
+	    case ASSERTION:
+	      assert(lit->code_max >= 1
+		     || lit->code_max <= ASSERT_LAST);
+	      if (assertions != NULL)
+		*assertions |= lit->code_max;
+	      break;
+	    case EMPTY:
+	      break;
+	    default:
+	      assert(0);
+	      break;
+	    }
+	  break;
+
+	case UNION:
+	  /* Subexpressions starting earlier take priority over ones
+	     starting later, so we prefer the left subexpression over the
+	     right subexpression. */
+	  uni = (tre_union_t *)node->obj;
+	  if (uni->left->nullable)
+	    STACK_PUSHX(stack, voidptr, uni->left)
+	  else if (uni->right->nullable)
+	    STACK_PUSHX(stack, voidptr, uni->right)
+	  else
+	    assert(0);
+	  break;
+
+	case CATENATION:
+	  /* The path must go through both children. */
+	  cat = (tre_catenation_t *)node->obj;
+	  assert(cat->left->nullable);
+	  assert(cat->right->nullable);
+	  STACK_PUSHX(stack, voidptr, cat->left);
+	  STACK_PUSHX(stack, voidptr, cat->right);
+	  break;
+
+	case ITERATION:
+	  /* A match with an empty string is preferred over no match at
+	     all, so we go through the argument if possible. */
+	  iter = (tre_iteration_t *)node->obj;
+	  if (iter->arg->nullable)
+	    STACK_PUSHX(stack, voidptr, iter->arg);
+	  break;
+
+	default:
+	  assert(0);
+	  break;
+	}
+    }
+
+  return status;
+}
+
+
+typedef enum {
+  NFL_RECURSE,
+  NFL_POST_UNION,
+  NFL_POST_CATENATION,
+  NFL_POST_ITERATION
+} tre_nfl_stack_symbol_t;
+
+
+/* Computes and fills in the fields `nullable', `firstpos', and `lastpos' for
+   the nodes of the AST `tree'. */
+static reg_errcode_t
+tre_compute_nfl(tre_mem_t mem, tre_stack_t *stack, tre_ast_node_t *tree)
+{
+  int bottom = tre_stack_num_objects(stack);
+
+  STACK_PUSHR(stack, voidptr, tree);
+  STACK_PUSHR(stack, int, NFL_RECURSE);
+
+  while (tre_stack_num_objects(stack) > bottom)
+    {
+      tre_nfl_stack_symbol_t symbol;
+      tre_ast_node_t *node;
+
+      symbol = (tre_nfl_stack_symbol_t)tre_stack_pop_int(stack);
+      node = tre_stack_pop_voidptr(stack);
+      switch (symbol)
+	{
+	case NFL_RECURSE:
+	  switch (node->type)
+	    {
+	    case LITERAL:
+	      {
+		tre_literal_t *lit = (tre_literal_t *)node->obj;
+		if (IS_BACKREF(lit))
+		  {
+		    /* Back references: nullable = false, firstpos = {i},
+		       lastpos = {i}. */
+		    node->nullable = 0;
+		    node->firstpos = tre_set_one(mem, lit->position, 0,
+					     TRE_CHAR_MAX, 0, NULL, -1);
+		    if (!node->firstpos)
+		      return REG_ESPACE;
+		    node->lastpos = tre_set_one(mem, lit->position, 0,
+						TRE_CHAR_MAX, 0, NULL,
+						(int)lit->code_max);
+		    if (!node->lastpos)
+		      return REG_ESPACE;
+		  }
+		else if (lit->code_min < 0)
+		  {
+		    /* Tags, empty strings, params, and zero width assertions:
+		       nullable = true, firstpos = {}, and lastpos = {}. */
+		    node->nullable = 1;
+		    node->firstpos = tre_set_empty(mem);
+		    if (!node->firstpos)
+		      return REG_ESPACE;
+		    node->lastpos = tre_set_empty(mem);
+		    if (!node->lastpos)
+		      return REG_ESPACE;
+		  }
+		else
+		  {
+		    /* Literal at position i: nullable = false, firstpos = {i},
+		       lastpos = {i}. */
+		    node->nullable = 0;
+		    node->firstpos =
+		      tre_set_one(mem, lit->position, (int)lit->code_min,
+				  (int)lit->code_max, 0, NULL, -1);
+		    if (!node->firstpos)
+		      return REG_ESPACE;
+		    node->lastpos = tre_set_one(mem, lit->position,
+						(int)lit->code_min,
+						(int)lit->code_max,
+						lit->class, lit->neg_classes,
+						-1);
+		    if (!node->lastpos)
+		      return REG_ESPACE;
+		  }
+		break;
+	      }
+
+	    case UNION:
+	      /* Compute the attributes for the two subtrees, and after that
+		 for this node. */
+	      STACK_PUSHR(stack, voidptr, node);
+	      STACK_PUSHR(stack, int, NFL_POST_UNION);
+	      STACK_PUSHR(stack, voidptr, ((tre_union_t *)node->obj)->right);
+	      STACK_PUSHR(stack, int, NFL_RECURSE);
+	      STACK_PUSHR(stack, voidptr, ((tre_union_t *)node->obj)->left);
+	      STACK_PUSHR(stack, int, NFL_RECURSE);
+	      break;
+
+	    case CATENATION:
+	      /* Compute the attributes for the two subtrees, and after that
+		 for this node. */
+	      STACK_PUSHR(stack, voidptr, node);
+	      STACK_PUSHR(stack, int, NFL_POST_CATENATION);
+	      STACK_PUSHR(stack, voidptr, ((tre_catenation_t *)node->obj)->right);
+	      STACK_PUSHR(stack, int, NFL_RECURSE);
+	      STACK_PUSHR(stack, voidptr, ((tre_catenation_t *)node->obj)->left);
+	      STACK_PUSHR(stack, int, NFL_RECURSE);
+	      break;
+
+	    case ITERATION:
+	      /* Compute the attributes for the subtree, and after that for
+		 this node. */
+	      STACK_PUSHR(stack, voidptr, node);
+	      STACK_PUSHR(stack, int, NFL_POST_ITERATION);
+	      STACK_PUSHR(stack, voidptr, ((tre_iteration_t *)node->obj)->arg);
+	      STACK_PUSHR(stack, int, NFL_RECURSE);
+	      break;
+	    }
+	  break; /* end case: NFL_RECURSE */
+
+	case NFL_POST_UNION:
+	  {
+	    tre_union_t *uni = (tre_union_t *)node->obj;
+	    node->nullable = uni->left->nullable || uni->right->nullable;
+	    node->firstpos = tre_set_union(mem, uni->left->firstpos,
+					   uni->right->firstpos, NULL, 0);
+	    if (!node->firstpos)
+	      return REG_ESPACE;
+	    node->lastpos = tre_set_union(mem, uni->left->lastpos,
+					  uni->right->lastpos, NULL, 0);
+	    if (!node->lastpos)
+	      return REG_ESPACE;
+	    break;
+	  }
+
+	case NFL_POST_ITERATION:
+	  {
+	    tre_iteration_t *iter = (tre_iteration_t *)node->obj;
+
+	    if (iter->min == 0 || iter->arg->nullable)
+	      node->nullable = 1;
+	    else
+	      node->nullable = 0;
+	    node->firstpos = iter->arg->firstpos;
+	    node->lastpos = iter->arg->lastpos;
+	    break;
+	  }
+
+	case NFL_POST_CATENATION:
+	  {
+	    int num_tags, *tags, assertions;
+	    reg_errcode_t status;
+	    tre_catenation_t *cat = node->obj;
+	    node->nullable = cat->left->nullable && cat->right->nullable;
+
+	    /* Compute firstpos. */
+	    if (cat->left->nullable)
+	      {
+		/* The left side matches the empty string.  Make a first pass
+		   with tre_match_empty() to get the number of tags and
+		   parameters. */
+		status = tre_match_empty(stack, cat->left,
+					 NULL, NULL, &num_tags);
+		if (status != REG_OK)
+		  return status;
+		/* Allocate arrays for the tags and parameters. */
+		tags = xmalloc(sizeof(*tags) * (num_tags + 1));
+		if (!tags)
+		  return REG_ESPACE;
+		tags[0] = -1;
+		assertions = 0;
+		/* Second pass with tre_mach_empty() to get the list of
+		   tags and parameters. */
+		status = tre_match_empty(stack, cat->left, tags,
+					 &assertions, NULL);
+		if (status != REG_OK)
+		  {
+		    xfree(tags);
+		    return status;
+		  }
+		node->firstpos =
+		  tre_set_union(mem, cat->right->firstpos, cat->left->firstpos,
+				tags, assertions);
+		xfree(tags);
+		if (!node->firstpos)
+		  return REG_ESPACE;
+	      }
+	    else
+	      {
+		node->firstpos = cat->left->firstpos;
+	      }
+
+	    /* Compute lastpos. */
+	    if (cat->right->nullable)
+	      {
+		/* The right side matches the empty string.  Make a first pass
+		   with tre_match_empty() to get the number of tags and
+		   parameters. */
+		status = tre_match_empty(stack, cat->right,
+					 NULL, NULL, &num_tags);
+		if (status != REG_OK)
+		  return status;
+		/* Allocate arrays for the tags and parameters. */
+		tags = xmalloc(sizeof(int) * (num_tags + 1));
+		if (!tags)
+		  return REG_ESPACE;
+		tags[0] = -1;
+		assertions = 0;
+		/* Second pass with tre_mach_empty() to get the list of
+		   tags and parameters. */
+		status = tre_match_empty(stack, cat->right, tags,
+					 &assertions, NULL);
+		if (status != REG_OK)
+		  {
+		    xfree(tags);
+		    return status;
+		  }
+		node->lastpos =
+		  tre_set_union(mem, cat->left->lastpos, cat->right->lastpos,
+				tags, assertions);
+		xfree(tags);
+		if (!node->lastpos)
+		  return REG_ESPACE;
+	      }
+	    else
+	      {
+		node->lastpos = cat->right->lastpos;
+	      }
+	    break;
+	  }
+
+	default:
+	  assert(0);
+	  break;
+	}
+    }
+
+  return REG_OK;
+}
+
+
+/* Adds a transition from each position in `p1' to each position in `p2'. */
+static reg_errcode_t
+tre_make_trans(tre_pos_and_tags_t *p1, tre_pos_and_tags_t *p2,
+	       tre_tnfa_transition_t *transitions,
+	       int *counts, int *offs)
+{
+  tre_pos_and_tags_t *orig_p2 = p2;
+  tre_tnfa_transition_t *trans;
+  int i, j, k, l, dup, prev_p2_pos;
+
+  if (transitions != NULL)
+    while (p1->position >= 0)
+      {
+	p2 = orig_p2;
+	prev_p2_pos = -1;
+	while (p2->position >= 0)
+	  {
+	    /* Optimization: if this position was already handled, skip it. */
+	    if (p2->position == prev_p2_pos)
+	      {
+		p2++;
+		continue;
+	      }
+	    prev_p2_pos = p2->position;
+	    /* Set `trans' to point to the next unused transition from
+	       position `p1->position'. */
+	    trans = transitions + offs[p1->position];
+	    while (trans->state != NULL)
+	      {
+#if 0
+		/* If we find a previous transition from `p1->position' to
+		   `p2->position', it is overwritten.  This can happen only
+		   if there are nested loops in the regexp, like in "((a)*)*".
+		   In POSIX.2 repetition using the outer loop is always
+		   preferred over using the inner loop.	 Therefore the
+		   transition for the inner loop is useless and can be thrown
+		   away. */
+		/* XXX - The same position is used for all nodes in a bracket
+		   expression, so this optimization cannot be used (it will
+		   break bracket expressions) unless I figure out a way to
+		   detect it here. */
+		if (trans->state_id == p2->position)
+		  {
+		    break;
+		  }
+#endif
+		trans++;
+	      }
+
+	    if (trans->state == NULL)
+	      (trans + 1)->state = NULL;
+	    /* Use the character ranges, assertions, etc. from `p1' for
+	       the transition from `p1' to `p2'. */
+	    trans->code_min = p1->code_min;
+	    trans->code_max = p1->code_max;
+	    trans->state = transitions + offs[p2->position];
+	    trans->state_id = p2->position;
+	    trans->assertions = p1->assertions | p2->assertions
+	      | (p1->class ? ASSERT_CHAR_CLASS : 0)
+	      | (p1->neg_classes != NULL ? ASSERT_CHAR_CLASS_NEG : 0);
+	    if (p1->backref >= 0)
+	      {
+		assert((trans->assertions & ASSERT_CHAR_CLASS) == 0);
+		assert(p2->backref < 0);
+		trans->u.backref = p1->backref;
+		trans->assertions |= ASSERT_BACKREF;
+	      }
+	    else
+	      trans->u.class = p1->class;
+	    if (p1->neg_classes != NULL)
+	      {
+		for (i = 0; p1->neg_classes[i] != (tre_ctype_t)0; i++);
+		trans->neg_classes =
+		  xmalloc(sizeof(*trans->neg_classes) * (i + 1));
+		if (trans->neg_classes == NULL)
+		  return REG_ESPACE;
+		for (i = 0; p1->neg_classes[i] != (tre_ctype_t)0; i++)
+		  trans->neg_classes[i] = p1->neg_classes[i];
+		trans->neg_classes[i] = (tre_ctype_t)0;
+	      }
+	    else
+	      trans->neg_classes = NULL;
+
+	    /* Find out how many tags this transition has. */
+	    i = 0;
+	    if (p1->tags != NULL)
+	      while(p1->tags[i] >= 0)
+		i++;
+	    j = 0;
+	    if (p2->tags != NULL)
+	      while(p2->tags[j] >= 0)
+		j++;
+
+	    /* If we are overwriting a transition, free the old tag array. */
+	    if (trans->tags != NULL)
+	      xfree(trans->tags);
+	    trans->tags = NULL;
+
+	    /* If there were any tags, allocate an array and fill it. */
+	    if (i + j > 0)
+	      {
+		trans->tags = xmalloc(sizeof(*trans->tags) * (i + j + 1));
+		if (!trans->tags)
+		  return REG_ESPACE;
+		i = 0;
+		if (p1->tags != NULL)
+		  while(p1->tags[i] >= 0)
+		    {
+		      trans->tags[i] = p1->tags[i];
+		      i++;
+		    }
+		l = i;
+		j = 0;
+		if (p2->tags != NULL)
+		  while (p2->tags[j] >= 0)
+		    {
+		      /* Don't add duplicates. */
+		      dup = 0;
+		      for (k = 0; k < i; k++)
+			if (trans->tags[k] == p2->tags[j])
+			  {
+			    dup = 1;
+			    break;
+			  }
+		      if (!dup)
+			trans->tags[l++] = p2->tags[j];
+		      j++;
+		    }
+		trans->tags[l] = -1;
+	      }
+
+	    p2++;
+	  }
+	p1++;
+      }
+  else
+    /* Compute a maximum limit for the number of transitions leaving
+       from each state. */
+    while (p1->position >= 0)
+      {
+	p2 = orig_p2;
+	while (p2->position >= 0)
+	  {
+	    counts[p1->position]++;
+	    p2++;
+	  }
+	p1++;
+      }
+  return REG_OK;
+}
+
+/* Converts the syntax tree to a TNFA.	All the transitions in the TNFA are
+   labelled with one character range (there are no transitions on empty
+   strings).  The TNFA takes O(n^2) space in the worst case, `n' is size of
+   the regexp. */
+static reg_errcode_t
+tre_ast_to_tnfa(tre_ast_node_t *node, tre_tnfa_transition_t *transitions,
+		int *counts, int *offs)
+{
+  tre_union_t *uni;
+  tre_catenation_t *cat;
+  tre_iteration_t *iter;
+  reg_errcode_t errcode = REG_OK;
+
+  /* XXX - recurse using a stack!. */
+  switch (node->type)
+    {
+    case LITERAL:
+      break;
+    case UNION:
+      uni = (tre_union_t *)node->obj;
+      errcode = tre_ast_to_tnfa(uni->left, transitions, counts, offs);
+      if (errcode != REG_OK)
+	return errcode;
+      errcode = tre_ast_to_tnfa(uni->right, transitions, counts, offs);
+      break;
+
+    case CATENATION:
+      cat = (tre_catenation_t *)node->obj;
+      /* Add a transition from each position in cat->left->lastpos
+	 to each position in cat->right->firstpos. */
+      errcode = tre_make_trans(cat->left->lastpos, cat->right->firstpos,
+			       transitions, counts, offs);
+      if (errcode != REG_OK)
+	return errcode;
+      errcode = tre_ast_to_tnfa(cat->left, transitions, counts, offs);
+      if (errcode != REG_OK)
+	return errcode;
+      errcode = tre_ast_to_tnfa(cat->right, transitions, counts, offs);
+      break;
+
+    case ITERATION:
+      iter = (tre_iteration_t *)node->obj;
+      assert(iter->max == -1 || iter->max == 1);
+
+      if (iter->max == -1)
+	{
+	  assert(iter->min == 0 || iter->min == 1);
+	  /* Add a transition from each last position in the iterated
+	     expression to each first position. */
+	  errcode = tre_make_trans(iter->arg->lastpos, iter->arg->firstpos,
+				   transitions, counts, offs);
+	  if (errcode != REG_OK)
+	    return errcode;
+	}
+      errcode = tre_ast_to_tnfa(iter->arg, transitions, counts, offs);
+      break;
+    }
+  return errcode;
+}
+
+
+#define ERROR_EXIT(err)		  \
+  do				  \
+    {				  \
+      errcode = err;		  \
+      if (/*CONSTCOND*/1)	  \
+      	goto error_exit;	  \
+    }				  \
+ while (/*CONSTCOND*/0)
+
+
+int
+regcomp(regex_t *restrict preg, const char *restrict regex, int cflags)
+{
+  tre_stack_t *stack;
+  tre_ast_node_t *tree, *tmp_ast_l, *tmp_ast_r;
+  tre_pos_and_tags_t *p;
+  int *counts = NULL, *offs = NULL;
+  int i, add = 0;
+  tre_tnfa_transition_t *transitions, *initial;
+  tre_tnfa_t *tnfa = NULL;
+  tre_submatch_data_t *submatch_data;
+  tre_tag_direction_t *tag_directions = NULL;
+  reg_errcode_t errcode;
+  tre_mem_t mem;
+
+  /* Parse context. */
+  tre_parse_ctx_t parse_ctx;
+
+  /* Allocate a stack used throughout the compilation process for various
+     purposes. */
+  stack = tre_stack_new(512, 1024000, 128);
+  if (!stack)
+    return REG_ESPACE;
+  /* Allocate a fast memory allocator. */
+  mem = tre_mem_new();
+  if (!mem)
+    {
+      tre_stack_destroy(stack);
+      return REG_ESPACE;
+    }
+
+  /* Parse the regexp. */
+  memset(&parse_ctx, 0, sizeof(parse_ctx));
+  parse_ctx.mem = mem;
+  parse_ctx.stack = stack;
+  parse_ctx.start = regex;
+  parse_ctx.cflags = cflags;
+  parse_ctx.max_backref = -1;
+  errcode = tre_parse(&parse_ctx);
+  if (errcode != REG_OK)
+    ERROR_EXIT(errcode);
+  preg->re_nsub = parse_ctx.submatch_id - 1;
+  tree = parse_ctx.n;
+
+#ifdef TRE_DEBUG
+  tre_ast_print(tree);
+#endif /* TRE_DEBUG */
+
+  /* Referring to nonexistent subexpressions is illegal. */
+  if (parse_ctx.max_backref > (int)preg->re_nsub)
+    ERROR_EXIT(REG_ESUBREG);
+
+  /* Allocate the TNFA struct. */
+  tnfa = xcalloc(1, sizeof(tre_tnfa_t));
+  if (tnfa == NULL)
+    ERROR_EXIT(REG_ESPACE);
+  tnfa->have_backrefs = parse_ctx.max_backref >= 0;
+  tnfa->have_approx = 0;
+  tnfa->num_submatches = parse_ctx.submatch_id;
+
+  /* Set up tags for submatch addressing.  If REG_NOSUB is set and the
+     regexp does not have back references, this can be skipped. */
+  if (tnfa->have_backrefs || !(cflags & REG_NOSUB))
+    {
+
+      /* Figure out how many tags we will need. */
+      errcode = tre_add_tags(NULL, stack, tree, tnfa);
+      if (errcode != REG_OK)
+	ERROR_EXIT(errcode);
+
+      if (tnfa->num_tags > 0)
+	{
+	  tag_directions = xmalloc(sizeof(*tag_directions)
+				   * (tnfa->num_tags + 1));
+	  if (tag_directions == NULL)
+	    ERROR_EXIT(REG_ESPACE);
+	  tnfa->tag_directions = tag_directions;
+	  memset(tag_directions, -1,
+		 sizeof(*tag_directions) * (tnfa->num_tags + 1));
+	}
+      tnfa->minimal_tags = xcalloc((unsigned)tnfa->num_tags * 2 + 1,
+				   sizeof(*tnfa->minimal_tags));
+      if (tnfa->minimal_tags == NULL)
+	ERROR_EXIT(REG_ESPACE);
+
+      submatch_data = xcalloc((unsigned)parse_ctx.submatch_id,
+			      sizeof(*submatch_data));
+      if (submatch_data == NULL)
+	ERROR_EXIT(REG_ESPACE);
+      tnfa->submatch_data = submatch_data;
+
+      errcode = tre_add_tags(mem, stack, tree, tnfa);
+      if (errcode != REG_OK)
+	ERROR_EXIT(errcode);
+
+    }
+
+  /* Expand iteration nodes. */
+  errcode = tre_expand_ast(mem, stack, tree, &parse_ctx.position,
+			   tag_directions);
+  if (errcode != REG_OK)
+    ERROR_EXIT(errcode);
+
+  /* Add a dummy node for the final state.
+     XXX - For certain patterns this dummy node can be optimized away,
+	   for example "a*" or "ab*".	Figure out a simple way to detect
+	   this possibility. */
+  tmp_ast_l = tree;
+  tmp_ast_r = tre_ast_new_literal(mem, 0, 0, parse_ctx.position++);
+  if (tmp_ast_r == NULL)
+    ERROR_EXIT(REG_ESPACE);
+
+  tree = tre_ast_new_catenation(mem, tmp_ast_l, tmp_ast_r);
+  if (tree == NULL)
+    ERROR_EXIT(REG_ESPACE);
+
+  errcode = tre_compute_nfl(mem, stack, tree);
+  if (errcode != REG_OK)
+    ERROR_EXIT(errcode);
+
+  counts = xmalloc(sizeof(int) * parse_ctx.position);
+  if (counts == NULL)
+    ERROR_EXIT(REG_ESPACE);
+
+  offs = xmalloc(sizeof(int) * parse_ctx.position);
+  if (offs == NULL)
+    ERROR_EXIT(REG_ESPACE);
+
+  for (i = 0; i < parse_ctx.position; i++)
+    counts[i] = 0;
+  tre_ast_to_tnfa(tree, NULL, counts, NULL);
+
+  add = 0;
+  for (i = 0; i < parse_ctx.position; i++)
+    {
+      offs[i] = add;
+      add += counts[i] + 1;
+      counts[i] = 0;
+    }
+  transitions = xcalloc((unsigned)add + 1, sizeof(*transitions));
+  if (transitions == NULL)
+    ERROR_EXIT(REG_ESPACE);
+  tnfa->transitions = transitions;
+  tnfa->num_transitions = add;
+
+  errcode = tre_ast_to_tnfa(tree, transitions, counts, offs);
+  if (errcode != REG_OK)
+    ERROR_EXIT(errcode);
+
+  tnfa->firstpos_chars = NULL;
+
+  p = tree->firstpos;
+  i = 0;
+  while (p->position >= 0)
+    {
+      i++;
+      p++;
+    }
+
+  initial = xcalloc((unsigned)i + 1, sizeof(tre_tnfa_transition_t));
+  if (initial == NULL)
+    ERROR_EXIT(REG_ESPACE);
+  tnfa->initial = initial;
+
+  i = 0;
+  for (p = tree->firstpos; p->position >= 0; p++)
+    {
+      initial[i].state = transitions + offs[p->position];
+      initial[i].state_id = p->position;
+      initial[i].tags = NULL;
+      /* Copy the arrays p->tags, and p->params, they are allocated
+	 from a tre_mem object. */
+      if (p->tags)
+	{
+	  int j;
+	  for (j = 0; p->tags[j] >= 0; j++);
+	  initial[i].tags = xmalloc(sizeof(*p->tags) * (j + 1));
+	  if (!initial[i].tags)
+	    ERROR_EXIT(REG_ESPACE);
+	  memcpy(initial[i].tags, p->tags, sizeof(*p->tags) * (j + 1));
+	}
+      initial[i].assertions = p->assertions;
+      i++;
+    }
+  initial[i].state = NULL;
+
+  tnfa->num_transitions = add;
+  tnfa->final = transitions + offs[tree->lastpos[0].position];
+  tnfa->num_states = parse_ctx.position;
+  tnfa->cflags = cflags;
+
+  tre_mem_destroy(mem);
+  tre_stack_destroy(stack);
+  xfree(counts);
+  xfree(offs);
+
+  preg->TRE_REGEX_T_FIELD = (void *)tnfa;
+  return REG_OK;
+
+ error_exit:
+  /* Free everything that was allocated and return the error code. */
+  tre_mem_destroy(mem);
+  if (stack != NULL)
+    tre_stack_destroy(stack);
+  if (counts != NULL)
+    xfree(counts);
+  if (offs != NULL)
+    xfree(offs);
+  preg->TRE_REGEX_T_FIELD = (void *)tnfa;
+  regfree(preg);
+  return errcode;
+}
+
+
+
+
+void
+regfree(regex_t *preg)
+{
+  tre_tnfa_t *tnfa;
+  unsigned int i;
+  tre_tnfa_transition_t *trans;
+
+  tnfa = (void *)preg->TRE_REGEX_T_FIELD;
+  if (!tnfa)
+    return;
+
+  for (i = 0; i < tnfa->num_transitions; i++)
+    if (tnfa->transitions[i].state)
+      {
+	if (tnfa->transitions[i].tags)
+	  xfree(tnfa->transitions[i].tags);
+	if (tnfa->transitions[i].neg_classes)
+	  xfree(tnfa->transitions[i].neg_classes);
+      }
+  if (tnfa->transitions)
+    xfree(tnfa->transitions);
+
+  if (tnfa->initial)
+    {
+      for (trans = tnfa->initial; trans->state; trans++)
+	{
+	  if (trans->tags)
+	    xfree(trans->tags);
+	}
+      xfree(tnfa->initial);
+    }
+
+  if (tnfa->submatch_data)
+    {
+      for (i = 0; i < tnfa->num_submatches; i++)
+	if (tnfa->submatch_data[i].parents)
+	  xfree(tnfa->submatch_data[i].parents);
+      xfree(tnfa->submatch_data);
+    }
+
+  if (tnfa->tag_directions)
+    xfree(tnfa->tag_directions);
+  if (tnfa->firstpos_chars)
+    xfree(tnfa->firstpos_chars);
+  if (tnfa->minimal_tags)
+    xfree(tnfa->minimal_tags);
+  xfree(tnfa);
+}
\ No newline at end of file
diff --git a/lib/mlibc/options/posix/musl-generic-regex/regerror.c b/lib/mlibc/options/posix/musl-generic-regex/regerror.c
new file mode 100644
index 0000000..41e9a36
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/regerror.c
@@ -0,0 +1,37 @@
+#include <string.h>
+#include <regex.h>
+#include <stdio.h>
+// #include "locale_impl.h"
+
+/* Error message strings for error codes listed in `regex.h'.  This list
+   needs to be in sync with the codes listed there, naturally. */
+
+/* Converted to single string by Rich Felker to remove the need for
+ * data relocations at runtime, 27 Feb 2006. */
+
+static const char messages[] = {
+  "No error\0"
+  "No match\0"
+  "Invalid regexp\0"
+  "Unknown collating element\0"
+  "Unknown character class name\0"
+  "Trailing backslash\0"
+  "Invalid back reference\0"
+  "Missing ']'\0"
+  "Missing ')'\0"
+  "Missing '}'\0"
+  "Invalid contents of {}\0"
+  "Invalid character range\0"
+  "Out of memory\0"
+  "Repetition not preceded by valid expression\0"
+  "\0Unknown error"
+};
+
+size_t regerror(int e, const regex_t *restrict preg, char *restrict buf, size_t size)
+{
+	const char *s;
+	for (s=messages; e && *s; e--, s+=strlen(s)+1);
+	if (!*s) s++;
+	// s = LCTRANS_CUR(s);
+	return 1+snprintf(buf, size, "%s", s);
+}
diff --git a/lib/mlibc/options/posix/musl-generic-regex/regexec.c b/lib/mlibc/options/posix/musl-generic-regex/regexec.c
new file mode 100644
index 0000000..1a169ab
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/regexec.c
@@ -0,0 +1,1028 @@
+/*
+  regexec.c - TRE POSIX compatible matching functions (and more).
+
+  Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
+  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+#include <wctype.h>
+#include <limits.h>
+#include <stdint.h>
+
+#include <regex.h>
+
+#include "tre.h"
+
+#include <assert.h>
+
+static void
+tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags,
+		const tre_tnfa_t *tnfa, regoff_t *tags, regoff_t match_eo);
+
+/***********************************************************************
+ from tre-match-utils.h
+***********************************************************************/
+
+#define GET_NEXT_WCHAR() do {                                                 \
+    prev_c = next_c; pos += pos_add_next;                                     \
+    if ((pos_add_next = mbtowc(&next_c, str_byte, MB_LEN_MAX)) <= 0) {        \
+        if (pos_add_next < 0) { ret = REG_NOMATCH; goto error_exit; }         \
+        else pos_add_next++;                                                  \
+    }                                                                         \
+    str_byte += pos_add_next;                                                 \
+  } while (0)
+
+#define IS_WORD_CHAR(c)	 ((c) == L'_' || tre_isalnum(c))
+
+#define CHECK_ASSERTIONS(assertions)					      \
+  (((assertions & ASSERT_AT_BOL)					      \
+    && (pos > 0 || reg_notbol)						      \
+    && (prev_c != L'\n' || !reg_newline))				      \
+   || ((assertions & ASSERT_AT_EOL)					      \
+       && (next_c != L'\0' || reg_noteol)				      \
+       && (next_c != L'\n' || !reg_newline))				      \
+   || ((assertions & ASSERT_AT_BOW)					      \
+       && (IS_WORD_CHAR(prev_c) || !IS_WORD_CHAR(next_c)))	              \
+   || ((assertions & ASSERT_AT_EOW)					      \
+       && (!IS_WORD_CHAR(prev_c) || IS_WORD_CHAR(next_c)))		      \
+   || ((assertions & ASSERT_AT_WB)					      \
+       && (pos != 0 && next_c != L'\0'					      \
+	   && IS_WORD_CHAR(prev_c) == IS_WORD_CHAR(next_c)))		      \
+   || ((assertions & ASSERT_AT_WB_NEG)					      \
+       && (pos == 0 || next_c == L'\0'					      \
+	   || IS_WORD_CHAR(prev_c) != IS_WORD_CHAR(next_c))))
+
+#define CHECK_CHAR_CLASSES(trans_i, tnfa, eflags)                             \
+  (((trans_i->assertions & ASSERT_CHAR_CLASS)                                 \
+       && !(tnfa->cflags & REG_ICASE)                                         \
+       && !tre_isctype((tre_cint_t)prev_c, trans_i->u.class))                 \
+    || ((trans_i->assertions & ASSERT_CHAR_CLASS)                             \
+        && (tnfa->cflags & REG_ICASE)                                         \
+        && !tre_isctype(tre_tolower((tre_cint_t)prev_c),trans_i->u.class)     \
+	&& !tre_isctype(tre_toupper((tre_cint_t)prev_c),trans_i->u.class))    \
+    || ((trans_i->assertions & ASSERT_CHAR_CLASS_NEG)                         \
+        && tre_neg_char_classes_match(trans_i->neg_classes,(tre_cint_t)prev_c,\
+                                      tnfa->cflags & REG_ICASE)))
+
+
+
+
+/* Returns 1 if `t1' wins `t2', 0 otherwise. */
+static int
+tre_tag_order(int num_tags, tre_tag_direction_t *tag_directions,
+	      regoff_t *t1, regoff_t *t2)
+{
+  int i;
+  for (i = 0; i < num_tags; i++)
+    {
+      if (tag_directions[i] == TRE_TAG_MINIMIZE)
+	{
+	  if (t1[i] < t2[i])
+	    return 1;
+	  if (t1[i] > t2[i])
+	    return 0;
+	}
+      else
+	{
+	  if (t1[i] > t2[i])
+	    return 1;
+	  if (t1[i] < t2[i])
+	    return 0;
+	}
+    }
+  /*  assert(0);*/
+  return 0;
+}
+
+static int
+tre_neg_char_classes_match(tre_ctype_t *classes, tre_cint_t wc, int icase)
+{
+  while (*classes != (tre_ctype_t)0)
+    if ((!icase && tre_isctype(wc, *classes))
+	|| (icase && (tre_isctype(tre_toupper(wc), *classes)
+		      || tre_isctype(tre_tolower(wc), *classes))))
+      return 1; /* Match. */
+    else
+      classes++;
+  return 0; /* No match. */
+}
+
+
+/***********************************************************************
+ from tre-match-parallel.c
+***********************************************************************/
+
+/*
+  This algorithm searches for matches basically by reading characters
+  in the searched string one by one, starting at the beginning.	 All
+  matching paths in the TNFA are traversed in parallel.	 When two or
+  more paths reach the same state, exactly one is chosen according to
+  tag ordering rules; if returning submatches is not required it does
+  not matter which path is chosen.
+
+  The worst case time required for finding the leftmost and longest
+  match, or determining that there is no match, is always linearly
+  dependent on the length of the text being searched.
+
+  This algorithm cannot handle TNFAs with back referencing nodes.
+  See `tre-match-backtrack.c'.
+*/
+
+typedef struct {
+  tre_tnfa_transition_t *state;
+  regoff_t *tags;
+} tre_tnfa_reach_t;
+
+typedef struct {
+  regoff_t pos;
+  regoff_t **tags;
+} tre_reach_pos_t;
+
+
+static reg_errcode_t
+tre_tnfa_run_parallel(const tre_tnfa_t *tnfa, const void *string,
+		      regoff_t *match_tags, int eflags,
+		      regoff_t *match_end_ofs)
+{
+  /* State variables required by GET_NEXT_WCHAR. */
+  tre_char_t prev_c = 0, next_c = 0;
+  const char *str_byte = string;
+  regoff_t pos = -1;
+  regoff_t pos_add_next = 1;
+#ifdef TRE_MBSTATE
+  mbstate_t mbstate;
+#endif /* TRE_MBSTATE */
+  int reg_notbol = eflags & REG_NOTBOL;
+  int reg_noteol = eflags & REG_NOTEOL;
+  int reg_newline = tnfa->cflags & REG_NEWLINE;
+  reg_errcode_t ret;
+
+  char *buf;
+  tre_tnfa_transition_t *trans_i;
+  tre_tnfa_reach_t *reach, *reach_next, *reach_i, *reach_next_i;
+  tre_reach_pos_t *reach_pos;
+  int *tag_i;
+  int num_tags, i;
+
+  regoff_t match_eo = -1;	   /* end offset of match (-1 if no match found yet) */
+  int new_match = 0;
+  regoff_t *tmp_tags = NULL;
+  regoff_t *tmp_iptr;
+
+#ifdef TRE_MBSTATE
+  memset(&mbstate, '\0', sizeof(mbstate));
+#endif /* TRE_MBSTATE */
+
+  if (!match_tags)
+    num_tags = 0;
+  else
+    num_tags = tnfa->num_tags;
+
+  /* Allocate memory for temporary data required for matching.	This needs to
+     be done for every matching operation to be thread safe.  This allocates
+     everything in a single large block with calloc(). */
+  {
+    size_t tbytes, rbytes, pbytes, xbytes, total_bytes;
+    char *tmp_buf;
+
+    /* Ensure that tbytes and xbytes*num_states cannot overflow, and that
+     * they don't contribute more than 1/8 of SIZE_MAX to total_bytes. */
+    if (num_tags > SIZE_MAX/(8 * sizeof(regoff_t) * tnfa->num_states))
+      return REG_ESPACE;
+
+    /* Likewise check rbytes. */
+    if (tnfa->num_states+1 > SIZE_MAX/(8 * sizeof(*reach_next)))
+      return REG_ESPACE;
+
+    /* Likewise check pbytes. */
+    if (tnfa->num_states > SIZE_MAX/(8 * sizeof(*reach_pos)))
+      return REG_ESPACE;
+
+    /* Compute the length of the block we need. */
+    tbytes = sizeof(*tmp_tags) * num_tags;
+    rbytes = sizeof(*reach_next) * (tnfa->num_states + 1);
+    pbytes = sizeof(*reach_pos) * tnfa->num_states;
+    xbytes = sizeof(regoff_t) * num_tags;
+    total_bytes =
+      (sizeof(long) - 1) * 4 /* for alignment paddings */
+      + (rbytes + xbytes * tnfa->num_states) * 2 + tbytes + pbytes;
+
+    /* Allocate the memory. */
+    buf = calloc(total_bytes, 1);
+    if (buf == NULL)
+      return REG_ESPACE;
+
+    /* Get the various pointers within tmp_buf (properly aligned). */
+    tmp_tags = (void *)buf;
+    tmp_buf = buf + tbytes;
+    tmp_buf += ALIGN(tmp_buf, long);
+    reach_next = (void *)tmp_buf;
+    tmp_buf += rbytes;
+    tmp_buf += ALIGN(tmp_buf, long);
+    reach = (void *)tmp_buf;
+    tmp_buf += rbytes;
+    tmp_buf += ALIGN(tmp_buf, long);
+    reach_pos = (void *)tmp_buf;
+    tmp_buf += pbytes;
+    tmp_buf += ALIGN(tmp_buf, long);
+    for (i = 0; i < tnfa->num_states; i++)
+      {
+	reach[i].tags = (void *)tmp_buf;
+	tmp_buf += xbytes;
+	reach_next[i].tags = (void *)tmp_buf;
+	tmp_buf += xbytes;
+      }
+  }
+
+  for (i = 0; i < tnfa->num_states; i++)
+    reach_pos[i].pos = -1;
+
+  GET_NEXT_WCHAR();
+  pos = 0;
+
+  reach_next_i = reach_next;
+  while (1)
+    {
+      /* If no match found yet, add the initial states to `reach_next'. */
+      if (match_eo < 0)
+	{
+	  trans_i = tnfa->initial;
+	  while (trans_i->state != NULL)
+	    {
+	      if (reach_pos[trans_i->state_id].pos < pos)
+		{
+		  if (trans_i->assertions
+		      && CHECK_ASSERTIONS(trans_i->assertions))
+		    {
+		      trans_i++;
+		      continue;
+		    }
+
+		  reach_next_i->state = trans_i->state;
+		  for (i = 0; i < num_tags; i++)
+		    reach_next_i->tags[i] = -1;
+		  tag_i = trans_i->tags;
+		  if (tag_i)
+		    while (*tag_i >= 0)
+		      {
+			if (*tag_i < num_tags)
+			  reach_next_i->tags[*tag_i] = pos;
+			tag_i++;
+		      }
+		  if (reach_next_i->state == tnfa->final)
+		    {
+		      match_eo = pos;
+		      new_match = 1;
+		      for (i = 0; i < num_tags; i++)
+			match_tags[i] = reach_next_i->tags[i];
+		    }
+		  reach_pos[trans_i->state_id].pos = pos;
+		  reach_pos[trans_i->state_id].tags = &reach_next_i->tags;
+		  reach_next_i++;
+		}
+	      trans_i++;
+	    }
+	  reach_next_i->state = NULL;
+	}
+      else
+	{
+	  if (num_tags == 0 || reach_next_i == reach_next)
+	    /* We have found a match. */
+	    break;
+	}
+
+      /* Check for end of string. */
+      if (!next_c) break;
+
+      GET_NEXT_WCHAR();
+
+      /* Swap `reach' and `reach_next'. */
+      reach_i = reach;
+      reach = reach_next;
+      reach_next = reach_i;
+
+      /* For each state in `reach', weed out states that don't fulfill the
+	 minimal matching conditions. */
+      if (tnfa->num_minimals && new_match)
+	{
+	  new_match = 0;
+	  reach_next_i = reach_next;
+	  for (reach_i = reach; reach_i->state; reach_i++)
+	    {
+	      int skip = 0;
+	      for (i = 0; tnfa->minimal_tags[i] >= 0; i += 2)
+		{
+		  int end = tnfa->minimal_tags[i];
+		  int start = tnfa->minimal_tags[i + 1];
+		  if (end >= num_tags)
+		    {
+		      skip = 1;
+		      break;
+		    }
+		  else if (reach_i->tags[start] == match_tags[start]
+			   && reach_i->tags[end] < match_tags[end])
+		    {
+		      skip = 1;
+		      break;
+		    }
+		}
+	      if (!skip)
+		{
+		  reach_next_i->state = reach_i->state;
+		  tmp_iptr = reach_next_i->tags;
+		  reach_next_i->tags = reach_i->tags;
+		  reach_i->tags = tmp_iptr;
+		  reach_next_i++;
+		}
+	    }
+	  reach_next_i->state = NULL;
+
+	  /* Swap `reach' and `reach_next'. */
+	  reach_i = reach;
+	  reach = reach_next;
+	  reach_next = reach_i;
+	}
+
+      /* For each state in `reach' see if there is a transition leaving with
+	 the current input symbol to a state not yet in `reach_next', and
+	 add the destination states to `reach_next'. */
+      reach_next_i = reach_next;
+      for (reach_i = reach; reach_i->state; reach_i++)
+	{
+	  for (trans_i = reach_i->state; trans_i->state; trans_i++)
+	    {
+	      /* Does this transition match the input symbol? */
+	      if (trans_i->code_min <= (tre_cint_t)prev_c &&
+		  trans_i->code_max >= (tre_cint_t)prev_c)
+		{
+		  if (trans_i->assertions
+		      && (CHECK_ASSERTIONS(trans_i->assertions)
+			  || CHECK_CHAR_CLASSES(trans_i, tnfa, eflags)))
+		    {
+		      continue;
+		    }
+
+		  /* Compute the tags after this transition. */
+		  for (i = 0; i < num_tags; i++)
+		    tmp_tags[i] = reach_i->tags[i];
+		  tag_i = trans_i->tags;
+		  if (tag_i != NULL)
+		    while (*tag_i >= 0)
+		      {
+			if (*tag_i < num_tags)
+			  tmp_tags[*tag_i] = pos;
+			tag_i++;
+		      }
+
+		  if (reach_pos[trans_i->state_id].pos < pos)
+		    {
+		      /* Found an unvisited node. */
+		      reach_next_i->state = trans_i->state;
+		      tmp_iptr = reach_next_i->tags;
+		      reach_next_i->tags = tmp_tags;
+		      tmp_tags = tmp_iptr;
+		      reach_pos[trans_i->state_id].pos = pos;
+		      reach_pos[trans_i->state_id].tags = &reach_next_i->tags;
+
+		      if (reach_next_i->state == tnfa->final
+			  && (match_eo == -1
+			      || (num_tags > 0
+				  && reach_next_i->tags[0] <= match_tags[0])))
+			{
+			  match_eo = pos;
+			  new_match = 1;
+			  for (i = 0; i < num_tags; i++)
+			    match_tags[i] = reach_next_i->tags[i];
+			}
+		      reach_next_i++;
+
+		    }
+		  else
+		    {
+		      assert(reach_pos[trans_i->state_id].pos == pos);
+		      /* Another path has also reached this state.  We choose
+			 the winner by examining the tag values for both
+			 paths. */
+		      if (tre_tag_order(num_tags, tnfa->tag_directions,
+					tmp_tags,
+					*reach_pos[trans_i->state_id].tags))
+			{
+			  /* The new path wins. */
+			  tmp_iptr = *reach_pos[trans_i->state_id].tags;
+			  *reach_pos[trans_i->state_id].tags = tmp_tags;
+			  if (trans_i->state == tnfa->final)
+			    {
+			      match_eo = pos;
+			      new_match = 1;
+			      for (i = 0; i < num_tags; i++)
+				match_tags[i] = tmp_tags[i];
+			    }
+			  tmp_tags = tmp_iptr;
+			}
+		    }
+		}
+	    }
+	}
+      reach_next_i->state = NULL;
+    }
+
+  *match_end_ofs = match_eo;
+  ret = match_eo >= 0 ? REG_OK : REG_NOMATCH;
+error_exit:
+  xfree(buf);
+  return ret;
+}
+
+
+
+/***********************************************************************
+ from tre-match-backtrack.c
+***********************************************************************/
+
+/*
+  This matcher is for regexps that use back referencing.  Regexp matching
+  with back referencing is an NP-complete problem on the number of back
+  references.  The easiest way to match them is to use a backtracking
+  routine which basically goes through all possible paths in the TNFA
+  and chooses the one which results in the best (leftmost and longest)
+  match.  This can be spectacularly expensive and may run out of stack
+  space, but there really is no better known generic algorithm.	 Quoting
+  Henry Spencer from comp.compilers:
+  <URL: http://compilers.iecc.com/comparch/article/93-03-102>
+
+    POSIX.2 REs require longest match, which is really exciting to
+    implement since the obsolete ("basic") variant also includes
+    \<digit>.  I haven't found a better way of tackling this than doing
+    a preliminary match using a DFA (or simulation) on a modified RE
+    that just replicates subREs for \<digit>, and then doing a
+    backtracking match to determine whether the subRE matches were
+    right.  This can be rather slow, but I console myself with the
+    thought that people who use \<digit> deserve very slow execution.
+    (Pun unintentional but very appropriate.)
+
+*/
+
+typedef struct {
+  regoff_t pos;
+  const char *str_byte;
+  tre_tnfa_transition_t *state;
+  int state_id;
+  int next_c;
+  regoff_t *tags;
+#ifdef TRE_MBSTATE
+  mbstate_t mbstate;
+#endif /* TRE_MBSTATE */
+} tre_backtrack_item_t;
+
+typedef struct tre_backtrack_struct {
+  tre_backtrack_item_t item;
+  struct tre_backtrack_struct *prev;
+  struct tre_backtrack_struct *next;
+} *tre_backtrack_t;
+
+#ifdef TRE_MBSTATE
+#define BT_STACK_MBSTATE_IN  stack->item.mbstate = (mbstate)
+#define BT_STACK_MBSTATE_OUT (mbstate) = stack->item.mbstate
+#else /* !TRE_MBSTATE */
+#define BT_STACK_MBSTATE_IN
+#define BT_STACK_MBSTATE_OUT
+#endif /* !TRE_MBSTATE */
+
+#define tre_bt_mem_new		  tre_mem_new
+#define tre_bt_mem_alloc	  tre_mem_alloc
+#define tre_bt_mem_destroy	  tre_mem_destroy
+
+
+#define BT_STACK_PUSH(_pos, _str_byte, _str_wide, _state, _state_id, _next_c, _tags, _mbstate) \
+  do									      \
+    {									      \
+      int i;								      \
+      if (!stack->next)							      \
+	{								      \
+	  tre_backtrack_t s;						      \
+	  s = tre_bt_mem_alloc(mem, sizeof(*s));			      \
+	  if (!s)							      \
+	    {								      \
+	      tre_bt_mem_destroy(mem);					      \
+	      if (tags)							      \
+		xfree(tags);						      \
+	      if (pmatch)						      \
+		xfree(pmatch);						      \
+	      if (states_seen)						      \
+		xfree(states_seen);					      \
+	      return REG_ESPACE;					      \
+	    }								      \
+	  s->prev = stack;						      \
+	  s->next = NULL;						      \
+	  s->item.tags = tre_bt_mem_alloc(mem,				      \
+					  sizeof(*tags) * tnfa->num_tags);    \
+	  if (!s->item.tags)						      \
+	    {								      \
+	      tre_bt_mem_destroy(mem);					      \
+	      if (tags)							      \
+		xfree(tags);						      \
+	      if (pmatch)						      \
+		xfree(pmatch);						      \
+	      if (states_seen)						      \
+		xfree(states_seen);					      \
+	      return REG_ESPACE;					      \
+	    }								      \
+	  stack->next = s;						      \
+	  stack = s;							      \
+	}								      \
+      else								      \
+	stack = stack->next;						      \
+      stack->item.pos = (_pos);						      \
+      stack->item.str_byte = (_str_byte);				      \
+      stack->item.state = (_state);					      \
+      stack->item.state_id = (_state_id);				      \
+      stack->item.next_c = (_next_c);					      \
+      for (i = 0; i < tnfa->num_tags; i++)				      \
+	stack->item.tags[i] = (_tags)[i];				      \
+      BT_STACK_MBSTATE_IN;						      \
+    }									      \
+  while (0)
+
+#define BT_STACK_POP()							      \
+  do									      \
+    {									      \
+      int i;								      \
+      assert(stack->prev);						      \
+      pos = stack->item.pos;						      \
+      str_byte = stack->item.str_byte;					      \
+      state = stack->item.state;					      \
+      next_c = stack->item.next_c;					      \
+      for (i = 0; i < tnfa->num_tags; i++)				      \
+	tags[i] = stack->item.tags[i];					      \
+      BT_STACK_MBSTATE_OUT;						      \
+      stack = stack->prev;						      \
+    }									      \
+  while (0)
+
+#undef MIN
+#define MIN(a, b) ((a) <= (b) ? (a) : (b))
+
+static reg_errcode_t
+tre_tnfa_run_backtrack(const tre_tnfa_t *tnfa, const void *string,
+		       regoff_t *match_tags, int eflags, regoff_t *match_end_ofs)
+{
+  /* State variables required by GET_NEXT_WCHAR. */
+  tre_char_t prev_c = 0, next_c = 0;
+  const char *str_byte = string;
+  regoff_t pos = 0;
+  regoff_t pos_add_next = 1;
+#ifdef TRE_MBSTATE
+  mbstate_t mbstate;
+#endif /* TRE_MBSTATE */
+  int reg_notbol = eflags & REG_NOTBOL;
+  int reg_noteol = eflags & REG_NOTEOL;
+  int reg_newline = tnfa->cflags & REG_NEWLINE;
+
+  /* These are used to remember the necessary values of the above
+     variables to return to the position where the current search
+     started from. */
+  int next_c_start;
+  const char *str_byte_start;
+  regoff_t pos_start = -1;
+#ifdef TRE_MBSTATE
+  mbstate_t mbstate_start;
+#endif /* TRE_MBSTATE */
+
+  /* End offset of best match so far, or -1 if no match found yet. */
+  regoff_t match_eo = -1;
+  /* Tag arrays. */
+  int *next_tags;
+  regoff_t *tags = NULL;
+  /* Current TNFA state. */
+  tre_tnfa_transition_t *state;
+  int *states_seen = NULL;
+
+  /* Memory allocator to for allocating the backtracking stack. */
+  tre_mem_t mem = tre_bt_mem_new();
+
+  /* The backtracking stack. */
+  tre_backtrack_t stack;
+
+  tre_tnfa_transition_t *trans_i;
+  regmatch_t *pmatch = NULL;
+  int ret;
+
+#ifdef TRE_MBSTATE
+  memset(&mbstate, '\0', sizeof(mbstate));
+#endif /* TRE_MBSTATE */
+
+  if (!mem)
+    return REG_ESPACE;
+  stack = tre_bt_mem_alloc(mem, sizeof(*stack));
+  if (!stack)
+    {
+      ret = REG_ESPACE;
+      goto error_exit;
+    }
+  stack->prev = NULL;
+  stack->next = NULL;
+
+  if (tnfa->num_tags)
+    {
+      tags = xmalloc(sizeof(*tags) * tnfa->num_tags);
+      if (!tags)
+	{
+	  ret = REG_ESPACE;
+	  goto error_exit;
+	}
+    }
+  if (tnfa->num_submatches)
+    {
+      pmatch = xmalloc(sizeof(*pmatch) * tnfa->num_submatches);
+      if (!pmatch)
+	{
+	  ret = REG_ESPACE;
+	  goto error_exit;
+	}
+    }
+  if (tnfa->num_states)
+    {
+      states_seen = xmalloc(sizeof(*states_seen) * tnfa->num_states);
+      if (!states_seen)
+	{
+	  ret = REG_ESPACE;
+	  goto error_exit;
+	}
+    }
+
+ retry:
+  {
+    int i;
+    for (i = 0; i < tnfa->num_tags; i++)
+      {
+	tags[i] = -1;
+	if (match_tags)
+	  match_tags[i] = -1;
+      }
+    for (i = 0; i < tnfa->num_states; i++)
+      states_seen[i] = 0;
+  }
+
+  state = NULL;
+  pos = pos_start;
+  GET_NEXT_WCHAR();
+  pos_start = pos;
+  next_c_start = next_c;
+  str_byte_start = str_byte;
+#ifdef TRE_MBSTATE
+  mbstate_start = mbstate;
+#endif /* TRE_MBSTATE */
+
+  /* Handle initial states. */
+  next_tags = NULL;
+  for (trans_i = tnfa->initial; trans_i->state; trans_i++)
+    {
+      if (trans_i->assertions && CHECK_ASSERTIONS(trans_i->assertions))
+	{
+	  continue;
+	}
+      if (state == NULL)
+	{
+	  /* Start from this state. */
+	  state = trans_i->state;
+	  next_tags = trans_i->tags;
+	}
+      else
+	{
+	  /* Backtrack to this state. */
+	  BT_STACK_PUSH(pos, str_byte, 0, trans_i->state,
+			trans_i->state_id, next_c, tags, mbstate);
+	  {
+	    int *tmp = trans_i->tags;
+	    if (tmp)
+	      while (*tmp >= 0)
+		stack->item.tags[*tmp++] = pos;
+	  }
+	}
+    }
+
+  if (next_tags)
+    for (; *next_tags >= 0; next_tags++)
+      tags[*next_tags] = pos;
+
+
+  if (state == NULL)
+    goto backtrack;
+
+  while (1)
+    {
+      tre_tnfa_transition_t *next_state;
+      int empty_br_match;
+
+      if (state == tnfa->final)
+	{
+	  if (match_eo < pos
+	      || (match_eo == pos
+		  && match_tags
+		  && tre_tag_order(tnfa->num_tags, tnfa->tag_directions,
+				   tags, match_tags)))
+	    {
+	      int i;
+	      /* This match wins the previous match. */
+	      match_eo = pos;
+	      if (match_tags)
+		for (i = 0; i < tnfa->num_tags; i++)
+		  match_tags[i] = tags[i];
+	    }
+	  /* Our TNFAs never have transitions leaving from the final state,
+	     so we jump right to backtracking. */
+	  goto backtrack;
+	}
+
+      /* Go to the next character in the input string. */
+      empty_br_match = 0;
+      trans_i = state;
+      if (trans_i->state && trans_i->assertions & ASSERT_BACKREF)
+	{
+	  /* This is a back reference state.  All transitions leaving from
+	     this state have the same back reference "assertion".  Instead
+	     of reading the next character, we match the back reference. */
+	  regoff_t so, eo;
+	  int bt = trans_i->u.backref;
+	  regoff_t bt_len;
+	  int result;
+
+	  /* Get the substring we need to match against.  Remember to
+	     turn off REG_NOSUB temporarily. */
+	  tre_fill_pmatch(bt + 1, pmatch, tnfa->cflags & ~REG_NOSUB,
+			  tnfa, tags, pos);
+	  so = pmatch[bt].rm_so;
+	  eo = pmatch[bt].rm_eo;
+	  bt_len = eo - so;
+
+	  result = strncmp((const char*)string + so, str_byte - 1,
+				 (size_t)bt_len);
+
+	  if (result == 0)
+	    {
+	      /* Back reference matched.  Check for infinite loop. */
+	      if (bt_len == 0)
+		empty_br_match = 1;
+	      if (empty_br_match && states_seen[trans_i->state_id])
+		{
+		  goto backtrack;
+		}
+
+	      states_seen[trans_i->state_id] = empty_br_match;
+
+	      /* Advance in input string and resync `prev_c', `next_c'
+		 and pos. */
+	      str_byte += bt_len - 1;
+	      pos += bt_len - 1;
+	      GET_NEXT_WCHAR();
+	    }
+	  else
+	    {
+	      goto backtrack;
+	    }
+	}
+      else
+	{
+	  /* Check for end of string. */
+	  if (next_c == L'\0')
+		goto backtrack;
+
+	  /* Read the next character. */
+	  GET_NEXT_WCHAR();
+	}
+
+      next_state = NULL;
+      for (trans_i = state; trans_i->state; trans_i++)
+	{
+	  if (trans_i->code_min <= (tre_cint_t)prev_c
+	      && trans_i->code_max >= (tre_cint_t)prev_c)
+	    {
+	      if (trans_i->assertions
+		  && (CHECK_ASSERTIONS(trans_i->assertions)
+		      || CHECK_CHAR_CLASSES(trans_i, tnfa, eflags)))
+		{
+		  continue;
+		}
+
+	      if (next_state == NULL)
+		{
+		  /* First matching transition. */
+		  next_state = trans_i->state;
+		  next_tags = trans_i->tags;
+		}
+	      else
+		{
+		  /* Second matching transition.  We may need to backtrack here
+		     to take this transition instead of the first one, so we
+		     push this transition in the backtracking stack so we can
+		     jump back here if needed. */
+		  BT_STACK_PUSH(pos, str_byte, 0, trans_i->state,
+				trans_i->state_id, next_c, tags, mbstate);
+		  {
+		    int *tmp;
+		    for (tmp = trans_i->tags; tmp && *tmp >= 0; tmp++)
+		      stack->item.tags[*tmp] = pos;
+		  }
+#if 0 /* XXX - it's important not to look at all transitions here to keep
+	 the stack small! */
+		  break;
+#endif
+		}
+	    }
+	}
+
+      if (next_state != NULL)
+	{
+	  /* Matching transitions were found.  Take the first one. */
+	  state = next_state;
+
+	  /* Update the tag values. */
+	  if (next_tags)
+	    while (*next_tags >= 0)
+	      tags[*next_tags++] = pos;
+	}
+      else
+	{
+	backtrack:
+	  /* A matching transition was not found.  Try to backtrack. */
+	  if (stack->prev)
+	    {
+	      if (stack->item.state->assertions & ASSERT_BACKREF)
+		{
+		  states_seen[stack->item.state_id] = 0;
+		}
+
+	      BT_STACK_POP();
+	    }
+	  else if (match_eo < 0)
+	    {
+	      /* Try starting from a later position in the input string. */
+	      /* Check for end of string. */
+	      if (next_c == L'\0')
+		    {
+		      break;
+		    }
+	      next_c = next_c_start;
+#ifdef TRE_MBSTATE
+	      mbstate = mbstate_start;
+#endif /* TRE_MBSTATE */
+	      str_byte = str_byte_start;
+	      goto retry;
+	    }
+	  else
+	    {
+	      break;
+	    }
+	}
+    }
+
+  ret = match_eo >= 0 ? REG_OK : REG_NOMATCH;
+  *match_end_ofs = match_eo;
+
+ error_exit:
+  tre_bt_mem_destroy(mem);
+#ifndef TRE_USE_ALLOCA
+  if (tags)
+    xfree(tags);
+  if (pmatch)
+    xfree(pmatch);
+  if (states_seen)
+    xfree(states_seen);
+#endif /* !TRE_USE_ALLOCA */
+
+  return ret;
+}
+
+/***********************************************************************
+ from regexec.c
+***********************************************************************/
+
+/* Fills the POSIX.2 regmatch_t array according to the TNFA tag and match
+   endpoint values. */
+static void
+tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags,
+		const tre_tnfa_t *tnfa, regoff_t *tags, regoff_t match_eo)
+{
+  tre_submatch_data_t *submatch_data;
+  unsigned int i, j;
+  int *parents;
+
+  i = 0;
+  if (match_eo >= 0 && !(cflags & REG_NOSUB))
+    {
+      /* Construct submatch offsets from the tags. */
+      submatch_data = tnfa->submatch_data;
+      while (i < tnfa->num_submatches && i < nmatch)
+	{
+	  if (submatch_data[i].so_tag == tnfa->end_tag)
+	    pmatch[i].rm_so = match_eo;
+	  else
+	    pmatch[i].rm_so = tags[submatch_data[i].so_tag];
+
+	  if (submatch_data[i].eo_tag == tnfa->end_tag)
+	    pmatch[i].rm_eo = match_eo;
+	  else
+	    pmatch[i].rm_eo = tags[submatch_data[i].eo_tag];
+
+	  /* If either of the endpoints were not used, this submatch
+	     was not part of the match. */
+	  if (pmatch[i].rm_so == -1 || pmatch[i].rm_eo == -1)
+	    pmatch[i].rm_so = pmatch[i].rm_eo = -1;
+
+	  i++;
+	}
+      /* Reset all submatches that are not within all of their parent
+	 submatches. */
+      i = 0;
+      while (i < tnfa->num_submatches && i < nmatch)
+	{
+	  if (pmatch[i].rm_eo == -1)
+	    assert(pmatch[i].rm_so == -1);
+	  assert(pmatch[i].rm_so <= pmatch[i].rm_eo);
+
+	  parents = submatch_data[i].parents;
+	  if (parents != NULL)
+	    for (j = 0; parents[j] >= 0; j++)
+	      {
+		if (pmatch[i].rm_so < pmatch[parents[j]].rm_so
+		    || pmatch[i].rm_eo > pmatch[parents[j]].rm_eo)
+		  pmatch[i].rm_so = pmatch[i].rm_eo = -1;
+	      }
+	  i++;
+	}
+    }
+
+  while (i < nmatch)
+    {
+      pmatch[i].rm_so = -1;
+      pmatch[i].rm_eo = -1;
+      i++;
+    }
+}
+
+
+/*
+  Wrapper functions for POSIX compatible regexp matching.
+*/
+
+int
+regexec(const regex_t *restrict preg, const char *restrict string,
+	  size_t nmatch, regmatch_t pmatch[restrict], int eflags)
+{
+  tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD;
+  reg_errcode_t status;
+  regoff_t *tags = NULL, eo;
+  if (tnfa->cflags & REG_NOSUB) nmatch = 0;
+  if (tnfa->num_tags > 0 && nmatch > 0)
+    {
+      tags = xmalloc(sizeof(*tags) * tnfa->num_tags);
+      if (tags == NULL)
+	return REG_ESPACE;
+    }
+
+  /* Dispatch to the appropriate matcher. */
+  if (tnfa->have_backrefs)
+    {
+      /* The regex has back references, use the backtracking matcher. */
+      status = tre_tnfa_run_backtrack(tnfa, string, tags, eflags, &eo);
+    }
+  else
+    {
+      /* Exact matching, no back references, use the parallel matcher. */
+      status = tre_tnfa_run_parallel(tnfa, string, tags, eflags, &eo);
+    }
+
+  if (status == REG_OK)
+    /* A match was found, so fill the submatch registers. */
+    tre_fill_pmatch(nmatch, pmatch, tnfa->cflags, tnfa, tags, eo);
+  if (tags)
+    xfree(tags);
+  return status;
+}
\ No newline at end of file
diff --git a/lib/mlibc/options/posix/musl-generic-regex/tre-mem.c b/lib/mlibc/options/posix/musl-generic-regex/tre-mem.c
new file mode 100644
index 0000000..a3df685
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/tre-mem.c
@@ -0,0 +1,158 @@
+/*
+  tre-mem.c - TRE memory allocator
+
+  Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
+  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+/*
+  This memory allocator is for allocating small memory blocks efficiently
+  in terms of memory overhead and execution speed.  The allocated blocks
+  cannot be freed individually, only all at once.  There can be multiple
+  allocators, though.
+*/
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "tre.h"
+
+/*
+  This memory allocator is for allocating small memory blocks efficiently
+  in terms of memory overhead and execution speed.  The allocated blocks
+  cannot be freed individually, only all at once.  There can be multiple
+  allocators, though.
+*/
+
+/* Returns a new memory allocator or NULL if out of memory. */
+tre_mem_t
+tre_mem_new_impl(int provided, void *provided_block)
+{
+  tre_mem_t mem;
+  if (provided)
+    {
+      mem = provided_block;
+      memset(mem, 0, sizeof(*mem));
+    }
+  else
+    mem = xcalloc(1, sizeof(*mem));
+  if (mem == NULL)
+    return NULL;
+  return mem;
+}
+
+
+/* Frees the memory allocator and all memory allocated with it. */
+void
+tre_mem_destroy(tre_mem_t mem)
+{
+  tre_list_t *tmp, *l = mem->blocks;
+
+  while (l != NULL)
+    {
+      xfree(l->data);
+      tmp = l->next;
+      xfree(l);
+      l = tmp;
+    }
+  xfree(mem);
+}
+
+
+/* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
+   allocated block or NULL if an underlying malloc() failed. */
+void *
+tre_mem_alloc_impl(tre_mem_t mem, int provided, void *provided_block,
+		   int zero, size_t size)
+{
+  void *ptr;
+
+  if (mem->failed)
+    {
+      return NULL;
+    }
+
+  if (mem->n < size)
+    {
+      /* We need more memory than is available in the current block.
+	 Allocate a new block. */
+      tre_list_t *l;
+      if (provided)
+	{
+	  if (provided_block == NULL)
+	    {
+	      mem->failed = 1;
+	      return NULL;
+	    }
+	  mem->ptr = provided_block;
+	  mem->n = TRE_MEM_BLOCK_SIZE;
+	}
+      else
+	{
+	  int block_size;
+	  if (size * 8 > TRE_MEM_BLOCK_SIZE)
+	    block_size = size * 8;
+	  else
+	    block_size = TRE_MEM_BLOCK_SIZE;
+	  l = xmalloc(sizeof(*l));
+	  if (l == NULL)
+	    {
+	      mem->failed = 1;
+	      return NULL;
+	    }
+	  l->data = xmalloc(block_size);
+	  if (l->data == NULL)
+	    {
+	      xfree(l);
+	      mem->failed = 1;
+	      return NULL;
+	    }
+	  l->next = NULL;
+	  if (mem->current != NULL)
+	    mem->current->next = l;
+	  if (mem->blocks == NULL)
+	    mem->blocks = l;
+	  mem->current = l;
+	  mem->ptr = l->data;
+	  mem->n = block_size;
+	}
+    }
+
+  /* Make sure the next pointer will be aligned. */
+  size += ALIGN(mem->ptr + size, long);
+
+  /* Allocate from current block. */
+  ptr = mem->ptr;
+  mem->ptr += size;
+  mem->n -= size;
+
+  /* Set to zero if needed. */
+  if (zero)
+    memset(ptr, 0, size);
+
+  return ptr;
+}
\ No newline at end of file
diff --git a/lib/mlibc/options/posix/musl-generic-regex/tre.h b/lib/mlibc/options/posix/musl-generic-regex/tre.h
new file mode 100644
index 0000000..5891f75
--- /dev/null
+++ b/lib/mlibc/options/posix/musl-generic-regex/tre.h
@@ -0,0 +1,241 @@
+// Taken from musl tre.h
+/*
+  tre-internal.h - TRE internal definitions
+
+  Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
+  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include <regex.h>
+#include <wchar.h>
+#include <wctype.h>
+
+#define hidden __attribute__((__visibility__("hidden")))
+
+// TODO: These should probably go in limits.h
+#define CHARCLASS_NAME_MAX 14
+#define RE_DUP_MAX 255
+
+#undef  TRE_MBSTATE
+
+#define NDEBUG
+
+#define TRE_REGEX_T_FIELD __opaque
+typedef int reg_errcode_t;
+
+typedef wchar_t tre_char_t;
+
+#define DPRINT(msg) do { } while(0)
+
+#define elementsof(x)	( sizeof(x) / sizeof(x[0]) )
+
+#define tre_mbrtowc(pwc, s, n, ps) (mbtowc((pwc), (s), (n)))
+
+/* Wide characters. */
+typedef wint_t tre_cint_t;
+#define TRE_CHAR_MAX 0x10ffff
+
+#define tre_isalnum iswalnum
+#define tre_isalpha iswalpha
+#define tre_isblank iswblank
+#define tre_iscntrl iswcntrl
+#define tre_isdigit iswdigit
+#define tre_isgraph iswgraph
+#define tre_islower iswlower
+#define tre_isprint iswprint
+#define tre_ispunct iswpunct
+#define tre_isspace iswspace
+#define tre_isupper iswupper
+#define tre_isxdigit iswxdigit
+
+#define tre_tolower towlower
+#define tre_toupper towupper
+#define tre_strlen  wcslen
+
+/* Use system provided iswctype() and wctype(). */
+typedef wctype_t tre_ctype_t;
+#define tre_isctype iswctype
+#define tre_ctype   wctype
+
+/* Returns number of bytes to add to (char *)ptr to make it
+   properly aligned for the type. */
+#define ALIGN(ptr, type) \
+  ((((long)ptr) % sizeof(type)) \
+   ? (sizeof(type) - (((long)ptr) % sizeof(type))) \
+   : 0)
+
+#undef MAX
+#undef MIN
+#define MAX(a, b) (((a) >= (b)) ? (a) : (b))
+#define MIN(a, b) (((a) <= (b)) ? (a) : (b))
+
+/* TNFA transition type. A TNFA state is an array of transitions,
+   the terminator is a transition with NULL `state'. */
+typedef struct tnfa_transition tre_tnfa_transition_t;
+
+struct tnfa_transition {
+  /* Range of accepted characters. */
+  tre_cint_t code_min;
+  tre_cint_t code_max;
+  /* Pointer to the destination state. */
+  tre_tnfa_transition_t *state;
+  /* ID number of the destination state. */
+  int state_id;
+  /* -1 terminated array of tags (or NULL). */
+  int *tags;
+  /* Assertion bitmap. */
+  int assertions;
+  /* Assertion parameters. */
+  union {
+    /* Character class assertion. */
+    tre_ctype_t class;
+    /* Back reference assertion. */
+    int backref;
+  } u;
+  /* Negative character class assertions. */
+  tre_ctype_t *neg_classes;
+};
+
+
+/* Assertions. */
+#define ASSERT_AT_BOL		  1   /* Beginning of line. */
+#define ASSERT_AT_EOL		  2   /* End of line. */
+#define ASSERT_CHAR_CLASS	  4   /* Character class in `class'. */
+#define ASSERT_CHAR_CLASS_NEG	  8   /* Character classes in `neg_classes'. */
+#define ASSERT_AT_BOW		 16   /* Beginning of word. */
+#define ASSERT_AT_EOW		 32   /* End of word. */
+#define ASSERT_AT_WB		 64   /* Word boundary. */
+#define ASSERT_AT_WB_NEG	128   /* Not a word boundary. */
+#define ASSERT_BACKREF		256   /* A back reference in `backref'. */
+#define ASSERT_LAST		256
+
+/* Tag directions. */
+typedef enum {
+  TRE_TAG_MINIMIZE = 0,
+  TRE_TAG_MAXIMIZE = 1
+} tre_tag_direction_t;
+
+/* Instructions to compute submatch register values from tag values
+   after a successful match.  */
+struct tre_submatch_data {
+  /* Tag that gives the value for rm_so (submatch start offset). */
+  int so_tag;
+  /* Tag that gives the value for rm_eo (submatch end offset). */
+  int eo_tag;
+  /* List of submatches this submatch is contained in. */
+  int *parents;
+};
+
+typedef struct tre_submatch_data tre_submatch_data_t;
+
+
+/* TNFA definition. */
+typedef struct tnfa tre_tnfa_t;
+
+struct tnfa {
+  tre_tnfa_transition_t *transitions;
+  unsigned int num_transitions;
+  tre_tnfa_transition_t *initial;
+  tre_tnfa_transition_t *final;
+  tre_submatch_data_t *submatch_data;
+  char *firstpos_chars;
+  int first_char;
+  unsigned int num_submatches;
+  tre_tag_direction_t *tag_directions;
+  int *minimal_tags;
+  int num_tags;
+  int num_minimals;
+  int end_tag;
+  int num_states;
+  int cflags;
+  int have_backrefs;
+  int have_approx;
+};
+
+/* from tre-mem.h: */
+
+#define TRE_MEM_BLOCK_SIZE 1024
+
+typedef struct tre_list {
+  void *data;
+  struct tre_list *next;
+} tre_list_t;
+
+typedef struct tre_mem_struct {
+  tre_list_t *blocks;
+  tre_list_t *current;
+  char *ptr;
+  size_t n;
+  int failed;
+  void **provided;
+} *tre_mem_t;
+
+#ifndef __MLIBC_ABI_ONLY
+
+#define tre_mem_new_impl   __tre_mem_new_impl
+#define tre_mem_alloc_impl __tre_mem_alloc_impl
+#define tre_mem_destroy    __tre_mem_destroy
+
+hidden tre_mem_t tre_mem_new_impl(int provided, void *provided_block);
+hidden void *tre_mem_alloc_impl(tre_mem_t mem, int provided, void *provided_block,
+                                int zero, size_t size);
+
+/* Returns a new memory allocator or NULL if out of memory. */
+#define tre_mem_new()  tre_mem_new_impl(0, NULL)
+
+/* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
+   allocated block or NULL if an underlying malloc() failed. */
+#define tre_mem_alloc(mem, size) tre_mem_alloc_impl(mem, 0, NULL, 0, size)
+
+/* Allocates a block of `size' bytes from `mem'.  Returns a pointer to the
+   allocated block or NULL if an underlying malloc() failed.  The memory
+   is set to zero. */
+#define tre_mem_calloc(mem, size) tre_mem_alloc_impl(mem, 0, NULL, 1, size)
+
+#ifdef TRE_USE_ALLOCA
+/* alloca() versions.  Like above, but memory is allocated with alloca()
+   instead of malloc(). */
+
+#define tre_mem_newa() \
+  tre_mem_new_impl(1, alloca(sizeof(struct tre_mem_struct)))
+
+#define tre_mem_alloca(mem, size)					      \
+  ((mem)->n >= (size)							      \
+   ? tre_mem_alloc_impl((mem), 1, NULL, 0, (size))			      \
+   : tre_mem_alloc_impl((mem), 1, alloca(TRE_MEM_BLOCK_SIZE), 0, (size)))
+#endif /* TRE_USE_ALLOCA */
+
+
+/* Frees the memory allocator and all memory allocated with it. */
+hidden void tre_mem_destroy(tre_mem_t mem);
+
+#define xmalloc malloc
+#define xcalloc calloc
+#define xfree free
+#define xrealloc realloc
+
+#endif /* !__MLIBC_ABI_ONLY */