| /* SPDX-License-Identifier: LGPL-2.1 OR MIT */ |
| /* |
| * MIPS specific definitions for NOLIBC |
| * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu> |
| */ |
| |
| #ifndef _NOLIBC_ARCH_MIPS_H |
| #define _NOLIBC_ARCH_MIPS_H |
| |
| /* The struct returned by the stat() syscall. 88 bytes are returned by the |
| * syscall. |
| */ |
| struct sys_stat_struct { |
| unsigned int st_dev; |
| long st_pad1[3]; |
| unsigned long st_ino; |
| unsigned int st_mode; |
| unsigned int st_nlink; |
| unsigned int st_uid; |
| unsigned int st_gid; |
| unsigned int st_rdev; |
| long st_pad2[2]; |
| long st_size; |
| long st_pad3; |
| |
| long st_atime; |
| long st_atime_nsec; |
| long st_mtime; |
| long st_mtime_nsec; |
| |
| long st_ctime; |
| long st_ctime_nsec; |
| long st_blksize; |
| long st_blocks; |
| long st_pad4[14]; |
| }; |
| |
| /* Syscalls for MIPS ABI O32 : |
| * - WARNING! there's always a delayed slot! |
| * - WARNING again, the syntax is different, registers take a '$' and numbers |
| * do not. |
| * - registers are 32-bit |
| * - stack is 8-byte aligned |
| * - syscall number is passed in v0 (starts at 0xfa0). |
| * - arguments are in a0, a1, a2, a3, then the stack. The caller needs to |
| * leave some room in the stack for the callee to save a0..a3 if needed. |
| * - Many registers are clobbered, in fact only a0..a2 and s0..s8 are |
| * preserved. See: https://www.linux-mips.org/wiki/Syscall as well as |
| * scall32-o32.S in the kernel sources. |
| * - the system call is performed by calling "syscall" |
| * - syscall return comes in v0, and register a3 needs to be checked to know |
| * if an error occurred, in which case errno is in v0. |
| * - 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. |
| */ |
| |
| #define my_syscall0(num) \ |
| ({ \ |
| register long _num __asm__ ("v0") = (num); \ |
| register long _arg4 __asm__ ("a3"); \ |
| \ |
| __asm__ volatile ( \ |
| "addiu $sp, $sp, -32\n" \ |
| "syscall\n" \ |
| "addiu $sp, $sp, 32\n" \ |
| : "=r"(_num), "=r"(_arg4) \ |
| : "r"(_num) \ |
| : "memory", "cc", "at", "v1", "hi", "lo", \ |
| "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ |
| ); \ |
| _arg4 ? -_num : _num; \ |
| }) |
| |
| #define my_syscall1(num, arg1) \ |
| ({ \ |
| register long _num __asm__ ("v0") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg4 __asm__ ("a3"); \ |
| \ |
| __asm__ volatile ( \ |
| "addiu $sp, $sp, -32\n" \ |
| "syscall\n" \ |
| "addiu $sp, $sp, 32\n" \ |
| : "=r"(_num), "=r"(_arg4) \ |
| : "0"(_num), \ |
| "r"(_arg1) \ |
| : "memory", "cc", "at", "v1", "hi", "lo", \ |
| "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ |
| ); \ |
| _arg4 ? -_num : _num; \ |
| }) |
| |
| #define my_syscall2(num, arg1, arg2) \ |
| ({ \ |
| register long _num __asm__ ("v0") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| register long _arg4 __asm__ ("a3"); \ |
| \ |
| __asm__ volatile ( \ |
| "addiu $sp, $sp, -32\n" \ |
| "syscall\n" \ |
| "addiu $sp, $sp, 32\n" \ |
| : "=r"(_num), "=r"(_arg4) \ |
| : "0"(_num), \ |
| "r"(_arg1), "r"(_arg2) \ |
| : "memory", "cc", "at", "v1", "hi", "lo", \ |
| "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ |
| ); \ |
| _arg4 ? -_num : _num; \ |
| }) |
| |
| #define my_syscall3(num, arg1, arg2, arg3) \ |
| ({ \ |
| register long _num __asm__ ("v0") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| register long _arg3 __asm__ ("a2") = (long)(arg3); \ |
| register long _arg4 __asm__ ("a3"); \ |
| \ |
| __asm__ volatile ( \ |
| "addiu $sp, $sp, -32\n" \ |
| "syscall\n" \ |
| "addiu $sp, $sp, 32\n" \ |
| : "=r"(_num), "=r"(_arg4) \ |
| : "0"(_num), \ |
| "r"(_arg1), "r"(_arg2), "r"(_arg3) \ |
| : "memory", "cc", "at", "v1", "hi", "lo", \ |
| "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ |
| ); \ |
| _arg4 ? -_num : _num; \ |
| }) |
| |
| #define my_syscall4(num, arg1, arg2, arg3, arg4) \ |
| ({ \ |
| register long _num __asm__ ("v0") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| register long _arg3 __asm__ ("a2") = (long)(arg3); \ |
| register long _arg4 __asm__ ("a3") = (long)(arg4); \ |
| \ |
| __asm__ volatile ( \ |
| "addiu $sp, $sp, -32\n" \ |
| "syscall\n" \ |
| "addiu $sp, $sp, 32\n" \ |
| : "=r" (_num), "=r"(_arg4) \ |
| : "0"(_num), \ |
| "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ |
| : "memory", "cc", "at", "v1", "hi", "lo", \ |
| "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ |
| ); \ |
| _arg4 ? -_num : _num; \ |
| }) |
| |
| #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ |
| ({ \ |
| register long _num __asm__ ("v0") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| register long _arg3 __asm__ ("a2") = (long)(arg3); \ |
| register long _arg4 __asm__ ("a3") = (long)(arg4); \ |
| register long _arg5 = (long)(arg5); \ |
| \ |
| __asm__ volatile ( \ |
| "addiu $sp, $sp, -32\n" \ |
| "sw %7, 16($sp)\n" \ |
| "syscall\n " \ |
| "addiu $sp, $sp, 32\n" \ |
| : "=r" (_num), "=r"(_arg4) \ |
| : "0"(_num), \ |
| "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ |
| : "memory", "cc", "at", "v1", "hi", "lo", \ |
| "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ |
| ); \ |
| _arg4 ? -_num : _num; \ |
| }) |
| |
| char **environ __attribute__((weak)); |
| const unsigned long *_auxv __attribute__((weak)); |
| |
| /* startup code, note that it's called __start on MIPS */ |
| void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __start(void) |
| { |
| __asm__ volatile ( |
| //".set nomips16\n" |
| ".set push\n" |
| ".set noreorder\n" |
| ".option pic0\n" |
| //".ent __start\n" |
| //"__start:\n" |
| "lw $a0,($sp)\n" // argc was in the stack |
| "addiu $a1, $sp, 4\n" // argv = sp + 4 |
| "sll $a2, $a0, 2\n" // a2 = argc * 4 |
| "add $a2, $a2, $a1\n" // envp = argv + 4*argc ... |
| "addiu $a2, $a2, 4\n" // ... + 4 |
| "lui $a3, %hi(environ)\n" // load environ into a3 (hi) |
| "addiu $a3, %lo(environ)\n" // load environ into a3 (lo) |
| "sw $a2,($a3)\n" // store envp(a2) into environ |
| |
| "move $t0, $a2\n" // iterate t0 over envp, look for NULL |
| "0:" // do { |
| "lw $a3, ($t0)\n" // a3=*(t0); |
| "bne $a3, $0, 0b\n" // } while (a3); |
| "addiu $t0, $t0, 4\n" // delayed slot: t0+=4; |
| "lui $a3, %hi(_auxv)\n" // load _auxv into a3 (hi) |
| "addiu $a3, %lo(_auxv)\n" // load _auxv into a3 (lo) |
| "sw $t0, ($a3)\n" // store t0 into _auxv |
| |
| "li $t0, -8\n" |
| "and $sp, $sp, $t0\n" // sp must be 8-byte aligned |
| "addiu $sp,$sp,-16\n" // the callee expects to save a0..a3 there! |
| "jal main\n" // main() returns the status code, we'll exit with it. |
| "nop\n" // delayed slot |
| "move $a0, $v0\n" // retrieve 32-bit exit code from v0 |
| "li $v0, 4001\n" // NR_exit == 4001 |
| "syscall\n" |
| //".end __start\n" |
| ".set pop\n" |
| ); |
| __builtin_unreachable(); |
| } |
| |
| #endif // _NOLIBC_ARCH_MIPS_H |
