mirror of
https://github.com/jart/cosmopolitan.git
synced 2024-05-18 03:22:40 +00:00
2fc507c98f
* modelines: tw -> sw shiftwidth, not textwidth. * space-surround modelines * fix irregular modelines * Fix modeline in titlegen.c
53 lines
2.7 KiB
ArmAsm
53 lines
2.7 KiB
ArmAsm
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
|
|
│ vi: set noet ft=asm ts=8 sw=8 fenc=utf-8 :vi │
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2023 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/macros.internal.h"
|
|
|
|
// Invokes system call w/ arity of two.
|
|
//
|
|
// This function has three parameters. The first two are for
|
|
// args passed along to the system call. The third's for the
|
|
// the magic number, indicating which system call is called.
|
|
//
|
|
// The returned value follows the Linux kernel convention ie
|
|
// errors are returned as `-errno`, rather than -1 w/ errno.
|
|
//
|
|
// This helper should not be used to do cancelation points.
|
|
__syscall2:
|
|
#ifdef __aarch64__
|
|
mov x8,x2 // syscall number (linux)
|
|
mov x16,x2 // syscall number (xnu)
|
|
mov x9,0 // clear carry flag
|
|
adds x9,x9,0 // clear carry flag
|
|
svc 0
|
|
bcs 1f
|
|
ret
|
|
1: neg x0,x0
|
|
ret
|
|
#elif defined(__x86_64__)
|
|
mov %edx,%eax // arg3 -> syscall number
|
|
clc // linux saves carry flag
|
|
syscall // bsds set carry on errs
|
|
jnc 1f
|
|
neg %rax // normalizes to system v
|
|
1: ret
|
|
#else
|
|
#error "unsupported architecture"
|
|
#endif
|
|
.endfn __syscall2,globl
|