From bd5969fc876a10b18613302db7087ef3c40f18e1 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Thu, 7 Mar 2024 17:28:00 -0500
Subject: lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 lib/mlibc/sysdeps/aero/generic/thread.cpp | 55 +++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 lib/mlibc/sysdeps/aero/generic/thread.cpp

(limited to 'lib/mlibc/sysdeps/aero/generic/thread.cpp')

diff --git a/lib/mlibc/sysdeps/aero/generic/thread.cpp b/lib/mlibc/sysdeps/aero/generic/thread.cpp
new file mode 100644
index 0000000..bc9a449
--- /dev/null
+++ b/lib/mlibc/sysdeps/aero/generic/thread.cpp
@@ -0,0 +1,55 @@
+#include <mlibc/all-sysdeps.hpp>
+#include <mlibc/thread-entry.hpp>
+
+#include <bits/ensure.h>
+#include <mlibc/tcb.hpp>
+
+#include <sys/mman.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+extern "C" void __mlibc_enter_thread(void *entry, void *user_arg, Tcb *tcb) {
+    // Wait until our parent sets up the TID:
+    while (!__atomic_load_n(&tcb->tid, __ATOMIC_RELAXED))
+        mlibc::sys_futex_wait(&tcb->tid, 0, nullptr);
+
+    if (mlibc::sys_tcb_set(tcb))
+        __ensure(!"sys_tcb_set() failed");
+
+    tcb->invokeThreadFunc(entry, user_arg);
+
+    auto self = reinterpret_cast<Tcb *>(tcb);
+
+    __atomic_store_n(&self->didExit, 1, __ATOMIC_RELEASE);
+    mlibc::sys_futex_wake(&self->didExit);
+
+    mlibc::sys_thread_exit();
+}
+
+namespace mlibc {
+
+static constexpr size_t default_stacksize = 0x1000000;
+
+int sys_prepare_stack(void **stack, void *entry, void *user_arg, void *tcb,
+                      size_t *stack_size, size_t *guard_size, void **stack_base) {
+    if (!*stack_size)
+        *stack_size = default_stacksize;
+    *guard_size = 0;
+
+    if (*stack) {
+		*stack_base = *stack;
+    } else {
+        *stack_base = mmap(nullptr, *stack_size, PROT_READ | PROT_WRITE,
+                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    }
+	
+	uintptr_t *sp = reinterpret_cast<uintptr_t *>(reinterpret_cast<uintptr_t>(*stack_base) + *stack_size);
+
+    *--sp = reinterpret_cast<uintptr_t>(tcb);
+    *--sp = reinterpret_cast<uintptr_t>(user_arg);
+    *--sp = reinterpret_cast<uintptr_t>(entry);
+    *stack = reinterpret_cast<void *>(sp);
+    return 0;
+}
+} // namespace mlibc
-- 
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