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/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* ARM specific definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_ARCH_ARM_H
#define _NOLIBC_ARCH_ARM_H
/* O_* macros for fcntl/open are architecture-specific */
#define O_RDONLY 0
#define O_WRONLY 1
#define O_RDWR 2
#define O_CREAT 0x40
#define O_EXCL 0x80
#define O_NOCTTY 0x100
#define O_TRUNC 0x200
#define O_APPEND 0x400
#define O_NONBLOCK 0x800
#define O_DIRECTORY 0x4000
/* The struct returned by the stat() syscall, 32-bit only, the syscall returns
* exactly 56 bytes (stops before the unused array). In big endian, the format
* differs as devices are returned as short only.
*/
struct sys_stat_struct {
#if defined(__ARMEB__)
unsigned short st_dev;
unsigned short __pad1;
#else
unsigned long st_dev;
#endif
unsigned long st_ino;
unsigned short st_mode;
unsigned short st_nlink;
unsigned short st_uid;
unsigned short st_gid;
#if defined(__ARMEB__)
unsigned short st_rdev;
unsigned short __pad2;
#else
unsigned long st_rdev;
#endif
unsigned long st_size;
unsigned long st_blksize;
unsigned long st_blocks;
unsigned long st_atime;
unsigned long st_atime_nsec;
unsigned long st_mtime;
unsigned long st_mtime_nsec;
unsigned long st_ctime;
unsigned long st_ctime_nsec;
unsigned long __unused[2];
};
/* Syscalls for ARM in ARM or Thumb modes :
* - registers are 32-bit
* - stack is 8-byte aligned
* ( http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka4127.html)
* - syscall number is passed in r7
* - arguments are in r0, r1, r2, r3, r4, r5
* - the system call is performed by calling svc #0
* - syscall return comes in r0.
* - only lr is clobbered.
* - 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.
* - the syscall number is always specified last in order to allow to force
* some registers before (gcc refuses a %-register at the last position).
*
* Also, ARM supports the old_select syscall if newselect is not available
*/
#define __ARCH_WANT_SYS_OLD_SELECT
#define my_syscall0(num) \
({ \
register long _num __asm__ ("r7") = (num); \
register long _arg1 __asm__ ("r0"); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall1(num, arg1) \
({ \
register long _num __asm__ ("r7") = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
register long _num __asm__ ("r7") = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
register long _num __asm__ ("r7") = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
register long _num __asm__ ("r7") = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
register long _arg4 __asm__ ("r3") = (long)(arg4); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
register long _num __asm__ ("r7") = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
register long _arg4 __asm__ ("r3") = (long)(arg4); \
register long _arg5 __asm__ ("r4") = (long)(arg5); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r" (_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
/* startup code */
__asm__ (".section .text\n"
".weak _start\n"
".global _start\n"
"_start:\n"
#if defined(__THUMBEB__) || defined(__THUMBEL__)
/* We enter here in 32-bit mode but if some previous functions were in
* 16-bit mode, the assembler cannot know, so we need to tell it we're in
* 32-bit now, then switch to 16-bit (is there a better way to do it than
* adding 1 by hand ?) and tell the asm we're now in 16-bit mode so that
* it generates correct instructions. Note that we do not support thumb1.
*/
".code 32\n"
"add r0, pc, #1\n"
"bx r0\n"
".code 16\n"
#endif
"pop {%r0}\n" // argc was in the stack
"mov %r1, %sp\n" // argv = sp
"add %r2, %r1, %r0, lsl #2\n" // envp = argv + 4*argc ...
"add %r2, %r2, $4\n" // ... + 4
"and %r3, %r1, $-8\n" // AAPCS : sp must be 8-byte aligned in the
"mov %sp, %r3\n" // callee, an bl doesn't push (lr=pc)
"bl main\n" // main() returns the status code, we'll exit with it.
"movs r7, $1\n" // NR_exit == 1
"svc $0x00\n"
"");
#endif // _NOLIBC_ARCH_ARM_H
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