2022-02-08 00:23:17 +08:00
|
|
|
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
|
|
|
|
|
/*
|
|
|
|
|
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/* Below comes the architecture-specific code. For each architecture, we have
|
|
|
|
|
* the syscall declarations and the _start code definition. This is the only
|
|
|
|
|
* global part. On all architectures the kernel puts everything in the stack
|
|
|
|
|
* before jumping to _start just above us, without any return address (_start
|
2023-05-21 17:36:29 +08:00
|
|
|
* is not a function but an entry point). So at the stack pointer we find argc.
|
2022-02-08 00:23:17 +08:00
|
|
|
* Then argv[] begins, and ends at the first NULL. Then we have envp which
|
|
|
|
|
* starts and ends with a NULL as well. So envp=argv+argc+1.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#ifndef _NOLIBC_ARCH_H
|
|
|
|
|
#define _NOLIBC_ARCH_H
|
|
|
|
|
|
|
|
|
|
#if defined(__x86_64__)
|
|
|
|
|
#include "arch-x86_64.h"
|
|
|
|
|
#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
|
|
|
|
|
#include "arch-i386.h"
|
|
|
|
|
#elif defined(__ARM_EABI__)
|
|
|
|
|
#include "arch-arm.h"
|
|
|
|
|
#elif defined(__aarch64__)
|
|
|
|
|
#include "arch-aarch64.h"
|
2023-10-20 15:30:33 +08:00
|
|
|
#elif defined(__mips__)
|
2022-02-08 00:23:17 +08:00
|
|
|
#include "arch-mips.h"
|
tools/nolibc: add support for powerpc
Both syscall declarations and _start code definition are added for
powerpc to nolibc.
Like mips, powerpc uses a register (exactly, the summary overflow bit)
to record the error occurred, and uses another register to return the
value [1]. So, the return value of every syscall declaration must be
normalized to match the __sysret() helper, return -value when there is
an error, otheriwse, return value directly.
Glibc and musl use different methods to check the summary overflow bit,
glibc (sysdeps/unix/sysv/linux/powerpc/sysdep.h) saves the cr register
to r0 at first, and then check the summary overflow bit in cr0:
mfcr r0
r0 & (1 << 28) ? -r3 : r3
-->
10003c14: 7c 00 00 26 mfcr r0
10003c18: 74 09 10 00 andis. r9,r0,4096
10003c1c: 41 82 00 08 beq 0x10003c24
10003c20: 7c 63 00 d0 neg r3,r3
Musl (arch/powerpc/syscall_arch.h) directly checks the summary overflow
bit with the 'bns' instruction, it is smaller:
/* no summary overflow bit means no error, return value directly */
bns+ 1f
/* otherwise, return negated value */
neg r3, r3
1:
-->
10000418: 40 a3 00 08 bns 0x10000420
1000041c: 7c 63 00 d0 neg r3,r3
Like musl, Linux (arch/powerpc/include/asm/vdso/gettimeofday.h) uses the
same method for do_syscall_2() too.
Here applies the second method to get smaller size.
[1]: https://man7.org/linux/man-pages/man2/syscall.2.html
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 02:39:26 +08:00
|
|
|
#elif defined(__powerpc__)
|
|
|
|
|
#include "arch-powerpc.h"
|
2022-02-08 00:23:17 +08:00
|
|
|
#elif defined(__riscv)
|
|
|
|
|
#include "arch-riscv.h"
|
2023-01-09 16:09:07 +08:00
|
|
|
#elif defined(__s390x__)
|
|
|
|
|
#include "arch-s390.h"
|
2023-03-04 22:29:53 +08:00
|
|
|
#elif defined(__loongarch__)
|
|
|
|
|
#include "arch-loongarch.h"
|
2023-11-05 18:07:05 +08:00
|
|
|
#else
|
|
|
|
|
#error Unsupported Architecture
|
2022-02-08 00:23:17 +08:00
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#endif /* _NOLIBC_ARCH_H */
|
