linux-zen-desktop/tools/include/nolibc/arch-aarch64.h

205 lines
10 KiB
C

/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* AARCH64 specific definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_ARCH_AARCH64_H
#define _NOLIBC_ARCH_AARCH64_H
#include "compiler.h"
/* The struct returned by the newfstatat() syscall. Differs slightly from the
* x86_64's stat one by field ordering, so be careful.
*/
struct sys_stat_struct {
unsigned long st_dev;
unsigned long st_ino;
unsigned int st_mode;
unsigned int st_nlink;
unsigned int st_uid;
unsigned int st_gid;
unsigned long st_rdev;
unsigned long __pad1;
long st_size;
int st_blksize;
int __pad2;
long st_blocks;
long st_atime;
unsigned long st_atime_nsec;
long st_mtime;
unsigned long st_mtime_nsec;
long st_ctime;
unsigned long st_ctime_nsec;
unsigned int __unused[2];
};
/* Syscalls for AARCH64 :
* - registers are 64-bit
* - stack is 16-byte aligned
* - syscall number is passed in x8
* - arguments are in x0, x1, x2, x3, x4, x5
* - the system call is performed by calling svc 0
* - syscall return comes in x0.
* - the arguments are cast to long and assigned into the target registers
* which are then simply passed as registers to the asm code, so that we
* don't have to experience issues with register constraints.
*
* On aarch64, select() is not implemented so we have to use pselect6().
*/
#define __ARCH_WANT_SYS_PSELECT6
#define my_syscall0(num) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0"); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall1(num, arg1) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
register long _arg4 __asm__ ("x3") = (long)(arg4); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
register long _arg4 __asm__ ("x3") = (long)(arg4); \
register long _arg5 __asm__ ("x4") = (long)(arg5); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r" (_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
register long _arg4 __asm__ ("x3") = (long)(arg4); \
register long _arg5 __asm__ ("x4") = (long)(arg5); \
register long _arg6 __asm__ ("x5") = (long)(arg6); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r" (_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_arg6), "r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
char **environ __attribute__((weak));
const unsigned long *_auxv __attribute__((weak));
/* startup code */
void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void)
{
__asm__ volatile (
#ifdef _NOLIBC_STACKPROTECTOR
"bl __stack_chk_init\n" /* initialize stack protector */
#endif
"ldr x0, [sp]\n" /* argc (x0) was in the stack */
"add x1, sp, 8\n" /* argv (x1) = sp */
"lsl x2, x0, 3\n" /* envp (x2) = 8*argc ... */
"add x2, x2, 8\n" /* + 8 (skip null) */
"add x2, x2, x1\n" /* + argv */
"adrp x3, environ\n" /* x3 = &environ (high bits) */
"str x2, [x3, #:lo12:environ]\n" /* store envp into environ */
"mov x4, x2\n" /* search for auxv (follows NULL after last env) */
"0:\n"
"ldr x5, [x4], 8\n" /* x5 = *x4; x4 += 8 */
"cbnz x5, 0b\n" /* and stop at NULL after last env */
"adrp x3, _auxv\n" /* x3 = &_auxv (high bits) */
"str x4, [x3, #:lo12:_auxv]\n" /* store x4 into _auxv */
"and sp, x1, -16\n" /* sp must be 16-byte aligned in the callee */
"bl main\n" /* main() returns the status code, we'll exit with it. */
"mov x8, 93\n" /* NR_exit == 93 */
"svc #0\n"
);
__builtin_unreachable();
}
#endif /* _NOLIBC_ARCH_AARCH64_H */