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| -rw-r--r-- | tools/include/nolibc/arch-arm.h | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h new file mode 100644 index 000000000000..f31be8e967d6 --- /dev/null +++ b/tools/include/nolibc/arch-arm.h @@ -0,0 +1,204 @@ +/* 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" + "_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 |