This commit is contained in:
Jessie
2024-01-26 22:50:50 -05:00
parent b0a2373215
commit b083ff2789
2 changed files with 32 additions and 3 deletions

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@@ -1,12 +1,18 @@
#![no_std]
#![no_std] #![feature(naked_functions)]
#[cfg(all(target_arch = "x86_64", target_os = "windows"))]
mod win64 {
#[used] #[no_mangle]
static _fltused: i32 = 0;
mod memcpy;
mod memset;
mod strlen;
mod memmove;
mod memcmp;
mod misc;
}
#[allow(unused)]
@@ -35,7 +41,5 @@ extern "system" {

25
src/win64/misc.rs Normal file
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@@ -0,0 +1,25 @@
#[no_mangle] #[naked]
pub unsafe extern "C" fn __chkstk() {
core::arch::asm!(
"push %rcx",
"cmp $0x1000,%rax",
"lea 16(%rsp),%rcx", // rsp before calling this routine -> rcx
"jb 1f",
"2:",
"sub $0x1000,%rcx",
"test %rcx,(%rcx)",
"sub $0x1000,%rax",
"cmp $0x1000,%rax",
"ja 2b",
"1:",
"sub %rax,%rcx",
"test %rcx,(%rcx)",
"lea 8(%rsp),%rax", // load pointer to the return address into rax
"mov %rcx,%rsp", // install the new top of stack pointer into rsp
"mov -8(%rax),%rcx", // restore rcx
"push (%rax)", // push return address onto the stack
"sub %rsp,%rax", // restore the original value in rax
"ret",
options(noreturn, att_syntax)
);
}