kernel: initramfs: Add initial OMAR port

CPIO is very outdated and its implementations varies on different hosts,
best to use OSMORA Archive Format (OMAR) instead!

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

4 files changed, 523 insertions, 0 deletions

diff --git a/tools/omar/Makefile b/tools/omar/Makefile
new file mode 100644
index 0000000..ee30260
--- /dev/null
+++ b/tools/omar/Makefile
@@ -0,0 +1,12 @@
+CFILES = $(shell find . -name "*.c")
+CFLAGS = -pedantic
+CC = gcc
+
+.PHONY: all
+all:
+	mkdir -p bin/
+	$(CC) $(CFLAGS) $(CFILES) -o bin/omar
+
+.PHONY: clean
+clean:
+	rm -rf bin/
diff --git a/tools/omar/README b/tools/omar/README
new file mode 100644
index 0000000..3c74d78
--- /dev/null
+++ b/tools/omar/README
@@ -0,0 +1,9 @@
+------------------------------
+OMAR - OSMORA Archive Format
+------------------------------
+
+OMAR is a minimal, bullshit free archive format aimed to replace
+the old and outdated CPIO (copy in/out) format.
+
+OMAR is designed for readonly in-memory filesystems (such as initramfs),
+with simplicity, clarity and "getting it done" in mind.
diff --git a/tools/omar/omar.1 b/tools/omar/omar.1
new file mode 100644
index 0000000..e59be31
--- /dev/null
+++ b/tools/omar/omar.1
@@ -0,0 +1,55 @@
+.\" Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
+.\" 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.
+.\" 3. Neither the name of Hyra nor the names of its
+.\"    contributors may be used to endorse or promote products derived from
+.\"    this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 OWNER 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.
+.Dd Apr 29 2025
+.Dt OMAR 1
+.Os HYRA
+.Sh NAME
+.Nm omar - OSMORA Archive Format
+.Sh SYNOPSIS
+omar -i [input] -o [output]
+
+.Sh DESCRIPTION
+Prepare files for use in an initramfs
+
+.Ft -i
+    input path directory
+
+.Ft -o
+    output path
+
+Upon creation of the archive image, OMAR will
+produce pathnames through stdout with the following
+types in square brackets ([])
+
+.Ft f
+    Regular file
+
+.Ft d
+    Directory
+
+.Sh AUTHORS
+.An Ian Moffett Aq Mt ian@osmora.org
diff --git a/tools/omar/omar.c b/tools/omar/omar.c
new file mode 100644
index 0000000..129303e
--- /dev/null
+++ b/tools/omar/omar.c
@@ -0,0 +1,447 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
+ * 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.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 OWNER 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 <sys/stat.h>
+#include <sys/errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <assert.h>
+#include <dirent.h>
+#include <string.h>
+#include <libgen.h>
+
+/* OMAR magic constants */
+#define OMAR_MAGIC "OMAR"
+#define OMAR_EOF "RAMO"
+
+/* OMAR type constants */
+#define OMAR_REG    0
+#define OMAR_DIR    1
+
+/* OMAR modes */
+#define OMAR_ARCHIVE  0
+#define OMAR_EXTRACT  1
+
+#define ALIGN_UP(value, align)        (((value) + (align)-1) & ~((align)-1))
+#define BLOCK_SIZE 512
+
+static int mode = OMAR_ARCHIVE;
+static int outfd;
+static const char *inpath = NULL;
+static const char *outpath = NULL;
+
+/*
+ * The OMAR file header, describes the basics
+ * of a file.
+ *
+ * @magic: Header magic ("OMAR")
+ * @len: Length of the file
+ * @namelen: Length of the filename
+ */
+struct omar_hdr {
+    char magic[4];
+    uint8_t type;
+    uint8_t namelen;
+    uint32_t len;
+} __attribute__((packed));
+
+static inline void
+help(void)
+{
+    printf("--------------------------------------\n");
+    printf("The OSMORA archive format\n");
+    printf("Usage: omar -i [input_dir] -o [output]\n");
+    printf("-h      Show this help screen\n");
+    printf("-x      Extract an OMAR archive\n");
+    printf("--------------------------------------\n");
+}
+
+/*
+ * Strip out root dir
+ *
+ * XXX: This is added code to work with Hyra
+ *      initramfs.
+ */
+static const char *
+strip_root(const char *path)
+{
+    const char *p;
+
+    for (p = path; *p != '\0'; ++p) {
+        if (*p == '/') {
+            ++p;
+            return p;
+        }
+    }
+
+    return NULL;
+}
+
+/*
+ * Recursive mkdir
+ */
+static void
+mkpath(const char *path)
+{
+    size_t len;
+    char buf[256];
+    char cwd[256];
+    char *p = NULL;
+
+    len = snprintf(buf, sizeof(buf), "%s", path);
+    if (buf[len - 1] == '/') {
+        buf[len - 1] = '\0';
+    }
+    for (p = (char *)buf + 1; *p != '\0'; ++p) {
+        if (*p == '/') {
+            *p = '\0';
+            mkdir(buf, 0700);
+            *p = '/';
+        }
+    }
+
+    mkdir(buf, 0700);
+}
+
+/*
+ * Push a file into the archive output
+ *
+ * @pathname: Full path name of file (NULL if EOF)
+ * @name: Name of file (for EOF, set to "EOF")
+ */
+static int
+file_push(const char *pathname, const char *name)
+{
+    struct omar_hdr hdr;
+    struct stat sb;
+    int infd, rem, error;
+    int pad_len;
+    size_t len;
+    char *buf;
+
+    hdr.type = OMAR_REG;
+
+    /* Attempt to open the input file if not EOF */
+    if (pathname != NULL) {
+        if ((infd = open(pathname, O_RDONLY)) < 0) {
+            perror("open");
+            return infd;
+        }
+
+        if ((error = fstat(infd, &sb)) < 0) {
+            return error;
+        }
+
+        if (S_ISDIR(sb.st_mode)) {
+            hdr.type = OMAR_DIR;
+        }
+    }
+
+    hdr.len = (pathname == NULL) ? 0 : sb.st_size;
+    hdr.namelen = strlen(name);
+
+    /*
+     * If we are at the end of the file, use the OMAR_EOF
+     * magic constant instant of the usual OMAR_MAGIC.
+     */
+    if (pathname == NULL) {
+        memcpy(hdr.magic, OMAR_EOF, sizeof(hdr.magic));
+    } else {
+        memcpy(hdr.magic, OMAR_MAGIC, sizeof(hdr.magic));
+    }
+
+    write(outfd, &hdr, sizeof(hdr));
+    write(outfd, name, hdr.namelen);
+
+    /* If we are at the end of file, we are done */
+    if (pathname == NULL) {
+        close(infd);
+        return 0;
+    }
+
+    /* Pad directories to zero */
+    if (hdr.type == OMAR_DIR) {
+        len = sizeof(hdr) + hdr.namelen;
+        rem = len & (BLOCK_SIZE - 1);
+        pad_len = BLOCK_SIZE - rem;
+
+        buf = malloc(pad_len);
+        memset(buf, 0, pad_len);
+        write(outfd, buf, pad_len);
+        free(buf);
+        return 0;
+    }
+
+    /* We need the file data now */
+    buf = malloc(hdr.len);
+    if (buf == NULL) {
+        printf("out of memory\n");
+        close(infd);
+        return -ENOMEM;
+    }
+    if (read(infd, buf, hdr.len) <= 0) {
+        perror("read");
+        close(infd);
+        return -EIO;
+    }
+
+    /*
+     * Write the actual file contents, if the file length is not
+     * a multiple of the block size, we'll need to pad out the rest
+     * to zero.
+     */
+    write(outfd, buf, hdr.len);
+    len = sizeof(hdr) + (hdr.namelen + hdr.len);
+    rem = len & (BLOCK_SIZE - 1);
+    if (rem != 0) {
+        /* Compute the padding length */
+        pad_len = BLOCK_SIZE - rem;
+
+        buf = realloc(buf, pad_len);
+        memset(buf, 0, pad_len);
+        write(outfd, buf, pad_len);
+    }
+    close(infd);
+    free(buf);
+    return 0;
+}
+
+/*
+ * Start creating an archive from the
+ * basepath of a directory.
+ */
+static int
+archive_create(const char *base, const char *dirname)
+{
+    DIR *dp;
+    struct dirent *ent;
+    struct omar_hdr hdr;
+    const char *p = NULL, *p1;
+    char pathbuf[256];
+    char namebuf[256];
+
+    dp = opendir(base);
+    if (dp == NULL) {
+        perror("opendir");
+        return -ENOENT;
+    }
+
+    while ((ent = readdir(dp)) != NULL) {
+        if (ent->d_name[0] == '.') {
+            continue;
+        }
+
+        snprintf(pathbuf, sizeof(pathbuf), "%s/%s", base, ent->d_name);
+        snprintf(namebuf, sizeof(namebuf), "%s/%s", dirname, ent->d_name);
+        p1 = strip_root(namebuf);
+
+        if (ent->d_type == DT_DIR) {
+            printf("%s [d]\n", p1);
+            file_push(pathbuf, p1);
+            archive_create(pathbuf, namebuf);
+        } else if (ent->d_type == DT_REG) {
+            printf("%s [f]\n", p1);
+            file_push(pathbuf, p1);
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * Extract a single file
+ *
+ * @data: Data to extract
+ * @len: Length of data
+ * @path: Path to output file
+ */
+static int
+extract_single(char *data, size_t len, const char *path)
+{
+    int fd;
+
+    if ((fd = open(path, O_WRONLY | O_CREAT, 0700)) < 0) {
+        return fd;
+    }
+
+    return write(fd, data, len) > 0 ? 0 : -1;
+}
+
+/*
+ * Extract an OMAR archive.
+ *
+ * XXX: The input file [-i] will be the OMAR archive to
+ *      be extracted, the output directory [-o] will be
+ *      where the files get extracted.
+ */
+static int
+archive_extract(void)
+{
+    char *buf, *name, *p;
+    struct stat sb;
+    struct omar_hdr *hdr;
+    int fd, error;
+    off_t off;
+    char namebuf[256];
+
+    if ((fd = open(inpath, O_RDONLY)) < 0) {
+        perror("open");
+        return fd;
+    }
+
+    if ((error = fstat(fd, &sb)) != 0) {
+        perror("fstat");
+        close(fd);
+        return error;
+    }
+
+    buf = malloc(sb.st_size);
+    if (buf == NULL) {
+        fprintf(stderr, "out of memory\n");
+        close(fd);
+        return -ENOMEM;
+    }
+
+    if (read(fd, buf, sb.st_size) <= 0) {
+        fprintf(stderr, "omar: no data read\n");
+        close(fd);
+        return -EIO;
+    }
+
+    hdr = (struct omar_hdr *)buf;
+    for (;;) {
+        if (memcmp(hdr->magic, OMAR_EOF, sizeof(OMAR_EOF)) == 0) {
+            printf("EOF!\n");
+            return 0;
+        }
+
+        /* Ensure the header is valid */
+        if (memcmp(hdr->magic, "OMAR", 4) != 0) {
+            fprintf(stderr, "bad magic\n");
+            break;
+        }
+
+        name = (char *)hdr + sizeof(struct omar_hdr);
+        memcpy(namebuf, name, hdr->namelen);
+        namebuf[hdr->namelen] = '\0';
+        printf("unpacking %s\n", namebuf);
+
+        if (hdr->type == OMAR_DIR) {
+            off = 512;
+            mkpath(namebuf);
+        } else {
+            off = ALIGN_UP(sizeof(hdr) + hdr->namelen + hdr->len, BLOCK_SIZE);
+            p = (char *)hdr + sizeof(struct omar_hdr);
+            p += hdr->namelen;
+            extract_single(p, hdr->len, namebuf);
+        }
+
+        hdr = (struct omar_hdr *)((char *)hdr + off);
+        memset(namebuf, 0, sizeof(namebuf));
+    }
+
+    free(buf);
+}
+
+int
+main(int argc, char **argv)
+{
+    int optc, retval;
+    int error, flags;
+
+    if (argc < 2) {
+        help();
+        return -1;
+    }
+
+    while ((optc = getopt(argc, argv, "xhi:o:")) != -1) {
+        switch (optc) {
+        case 'x':
+            mode = OMAR_EXTRACT;
+            break;
+        case 'i':
+            inpath = optarg;
+            break;
+        case 'o':
+            outpath = optarg;
+            break;
+        case 'h':
+            help();
+            return 0;
+        default:
+            help();
+            return -1;
+        }
+    }
+
+    if (inpath == NULL) {
+        fprintf(stderr, "omar: no input path\n");
+        help();
+        return -1;
+    }
+    if (outpath == NULL) {
+        fprintf(stderr, "omar: no output path\n");
+        help();
+        return -1;
+    }
+
+    /*
+     * Do our specific job based on the mode
+     * OMAR is set to be in.
+     */
+    switch (mode) {
+    case OMAR_ARCHIVE:
+        /* Begin archiving the file */
+        outfd = open(outpath, O_WRONLY | O_CREAT, 0700);
+        if (outfd < 0) {
+            printf("omar: failed to open output file\n");
+            return outfd;
+        }
+
+        retval = archive_create(inpath, basename((char *)inpath));
+        file_push(NULL, "EOF");
+        break;
+    case OMAR_EXTRACT:
+        /* Begin extracting the file */
+        if ((error = mkdir(outpath, 0700) != 0)) {
+            perror("mkdir");
+            return error;
+        }
+
+        retval = archive_extract();
+        break;
+    }
+    close(outfd);
+    return retval;
+}