FILE
arch-mips.h
File preview with syntax highlighting.
linux-6.19.14/tools/include/nolibc/arch-mips.h
1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ 2/* 3 * MIPS specific definitions for NOLIBC 4 * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu> 5 */ 6 7#ifndef _NOLIBC_ARCH_MIPS_H 8#define _NOLIBC_ARCH_MIPS_H 9 10#include "compiler.h" 11#include "crt.h" 12 13#if !defined(_ABIO32) && !defined(_ABIN32) && !defined(_ABI64) 14#error Unsupported MIPS ABI 15#endif 16 17/* Syscalls for MIPS ABI O32 : 18 * - WARNING! there's always a delayed slot! 19 * - WARNING again, the syntax is different, registers take a '$' and numbers 20 * do not. 21 * - registers are 32-bit 22 * - stack is 8-byte aligned 23 * - syscall number is passed in v0 (starts at 0xfa0). 24 * - arguments are in a0, a1, a2, a3, then the stack. The caller needs to 25 * leave some room in the stack for the callee to save a0..a3 if needed. 26 * - Many registers are clobbered, in fact only a0..a2 and s0..s8 are 27 * preserved. See: https://www.linux-mips.org/wiki/Syscall as well as 28 * scall32-o32.S in the kernel sources. 29 * - the system call is performed by calling "syscall" 30 * - syscall return comes in v0, and register a3 needs to be checked to know 31 * if an error occurred, in which case errno is in v0. 32 * - the arguments are cast to long and assigned into the target registers 33 * which are then simply passed as registers to the asm code, so that we 34 * don't have to experience issues with register constraints. 35 * 36 * Syscalls for MIPS ABI N32, same as ABI O32 with the following differences : 37 * - arguments are in a0, a1, a2, a3, t0, t1, t2, t3. 38 * t0..t3 are also known as a4..a7. 39 * - stack is 16-byte aligned 40 */ 41 42#if defined(_ABIO32) 43 44#define _NOLIBC_SYSCALL_CLOBBERLIST \ 45 "memory", "cc", "at", "v1", "hi", "lo", \ 46 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" 47#define _NOLIBC_SYSCALL_STACK_RESERVE "addiu $sp, $sp, -32\n" 48#define _NOLIBC_SYSCALL_STACK_UNRESERVE "addiu $sp, $sp, 32\n" 49 50#else /* _ABIN32 || _ABI64 */ 51 52/* binutils, GCC and clang disagree about register aliases, use numbers instead. */ 53#define _NOLIBC_SYSCALL_CLOBBERLIST \ 54 "memory", "cc", "at", "v1", \ 55 "10", "11", "12", "13", "14", "15", "24", "25" 56 57#define _NOLIBC_SYSCALL_STACK_RESERVE 58#define _NOLIBC_SYSCALL_STACK_UNRESERVE 59 60#endif /* _ABIO32 */ 61 62#define my_syscall0(num) \ 63({ \ 64 register long _num __asm__ ("v0") = (num); \ 65 register long _arg4 __asm__ ("a3"); \ 66 \ 67 __asm__ volatile ( \ 68 _NOLIBC_SYSCALL_STACK_RESERVE \ 69 "syscall\n" \ 70 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 71 : "=r"(_num), "=r"(_arg4) \ 72 : "r"(_num) \ 73 : _NOLIBC_SYSCALL_CLOBBERLIST \ 74 ); \ 75 _arg4 ? -_num : _num; \ 76}) 77 78#define my_syscall1(num, arg1) \ 79({ \ 80 register long _num __asm__ ("v0") = (num); \ 81 register long _arg1 __asm__ ("a0") = (long)(arg1); \ 82 register long _arg4 __asm__ ("a3"); \ 83 \ 84 __asm__ volatile ( \ 85 _NOLIBC_SYSCALL_STACK_RESERVE \ 86 "syscall\n" \ 87 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 88 : "=r"(_num), "=r"(_arg4) \ 89 : "0"(_num), \ 90 "r"(_arg1) \ 91 : _NOLIBC_SYSCALL_CLOBBERLIST \ 92 ); \ 93 _arg4 ? -_num : _num; \ 94}) 95 96#define my_syscall2(num, arg1, arg2) \ 97({ \ 98 register long _num __asm__ ("v0") = (num); \ 99 register long _arg1 __asm__ ("a0") = (long)(arg1); \ 100 register long _arg2 __asm__ ("a1") = (long)(arg2); \ 101 register long _arg4 __asm__ ("a3"); \ 102 \ 103 __asm__ volatile ( \ 104 _NOLIBC_SYSCALL_STACK_RESERVE \ 105 "syscall\n" \ 106 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 107 : "=r"(_num), "=r"(_arg4) \ 108 : "0"(_num), \ 109 "r"(_arg1), "r"(_arg2) \ 110 : _NOLIBC_SYSCALL_CLOBBERLIST \ 111 ); \ 112 _arg4 ? -_num : _num; \ 113}) 114 115#define my_syscall3(num, arg1, arg2, arg3) \ 116({ \ 117 register long _num __asm__ ("v0") = (num); \ 118 register long _arg1 __asm__ ("a0") = (long)(arg1); \ 119 register long _arg2 __asm__ ("a1") = (long)(arg2); \ 120 register long _arg3 __asm__ ("a2") = (long)(arg3); \ 121 register long _arg4 __asm__ ("a3"); \ 122 \ 123 __asm__ volatile ( \ 124 _NOLIBC_SYSCALL_STACK_RESERVE \ 125 "syscall\n" \ 126 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 127 : "=r"(_num), "=r"(_arg4) \ 128 : "0"(_num), \ 129 "r"(_arg1), "r"(_arg2), "r"(_arg3) \ 130 : _NOLIBC_SYSCALL_CLOBBERLIST \ 131 ); \ 132 _arg4 ? -_num : _num; \ 133}) 134 135#define my_syscall4(num, arg1, arg2, arg3, arg4) \ 136({ \ 137 register long _num __asm__ ("v0") = (num); \ 138 register long _arg1 __asm__ ("a0") = (long)(arg1); \ 139 register long _arg2 __asm__ ("a1") = (long)(arg2); \ 140 register long _arg3 __asm__ ("a2") = (long)(arg3); \ 141 register long _arg4 __asm__ ("a3") = (long)(arg4); \ 142 \ 143 __asm__ volatile ( \ 144 _NOLIBC_SYSCALL_STACK_RESERVE \ 145 "syscall\n" \ 146 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 147 : "=r" (_num), "=r"(_arg4) \ 148 : "0"(_num), \ 149 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ 150 : _NOLIBC_SYSCALL_CLOBBERLIST \ 151 ); \ 152 _arg4 ? -_num : _num; \ 153}) 154 155#if defined(_ABIO32) 156 157#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ 158({ \ 159 register long _num __asm__ ("v0") = (num); \ 160 register long _arg1 __asm__ ("a0") = (long)(arg1); \ 161 register long _arg2 __asm__ ("a1") = (long)(arg2); \ 162 register long _arg3 __asm__ ("a2") = (long)(arg3); \ 163 register long _arg4 __asm__ ("a3") = (long)(arg4); \ 164 register long _arg5 = (long)(arg5); \ 165 \ 166 __asm__ volatile ( \ 167 _NOLIBC_SYSCALL_STACK_RESERVE \ 168 "sw %7, 16($sp)\n" \ 169 "syscall\n" \ 170 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 171 : "=r" (_num), "=r"(_arg4) \ 172 : "0"(_num), \ 173 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ 174 : _NOLIBC_SYSCALL_CLOBBERLIST \ 175 ); \ 176 _arg4 ? -_num : _num; \ 177}) 178 179#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ 180({ \ 181 register long _num __asm__ ("v0") = (num); \ 182 register long _arg1 __asm__ ("a0") = (long)(arg1); \ 183 register long _arg2 __asm__ ("a1") = (long)(arg2); \ 184 register long _arg3 __asm__ ("a2") = (long)(arg3); \ 185 register long _arg4 __asm__ ("a3") = (long)(arg4); \ 186 register long _arg5 = (long)(arg5); \ 187 register long _arg6 = (long)(arg6); \ 188 \ 189 __asm__ volatile ( \ 190 _NOLIBC_SYSCALL_STACK_RESERVE \ 191 "sw %7, 16($sp)\n" \ 192 "sw %8, 20($sp)\n" \ 193 "syscall\n" \ 194 _NOLIBC_SYSCALL_STACK_UNRESERVE \ 195 : "=r" (_num), "=r"(_arg4) \ 196 : "0"(_num), \ 197 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ 198 "r"(_arg6) \ 199 : _NOLIBC_SYSCALL_CLOBBERLIST \ 200 ); \ 201 _arg4 ? -_num : _num; \ 202}) 203 204#else /* _ABIN32 || _ABI64 */ 205 206#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ 207({ \ 208 register long _num __asm__ ("v0") = (num); \ 209 register long _arg1 __asm__ ("$4") = (long)(arg1); \ 210 register long _arg2 __asm__ ("$5") = (long)(arg2); \ 211 register long _arg3 __asm__ ("$6") = (long)(arg3); \ 212 register long _arg4 __asm__ ("$7") = (long)(arg4); \ 213 register long _arg5 __asm__ ("$8") = (long)(arg5); \ 214 \ 215 __asm__ volatile ( \ 216 "syscall\n" \ 217 : "=r" (_num), "=r"(_arg4) \ 218 : "0"(_num), \ 219 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ 220 : _NOLIBC_SYSCALL_CLOBBERLIST \ 221 ); \ 222 _arg4 ? -_num : _num; \ 223}) 224 225#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ 226({ \ 227 register long _num __asm__ ("v0") = (num); \ 228 register long _arg1 __asm__ ("$4") = (long)(arg1); \ 229 register long _arg2 __asm__ ("$5") = (long)(arg2); \ 230 register long _arg3 __asm__ ("$6") = (long)(arg3); \ 231 register long _arg4 __asm__ ("$7") = (long)(arg4); \ 232 register long _arg5 __asm__ ("$8") = (long)(arg5); \ 233 register long _arg6 __asm__ ("$9") = (long)(arg6); \ 234 \ 235 __asm__ volatile ( \ 236 "syscall\n" \ 237 : "=r" (_num), "=r"(_arg4) \ 238 : "0"(_num), \ 239 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ 240 "r"(_arg6) \ 241 : _NOLIBC_SYSCALL_CLOBBERLIST \ 242 ); \ 243 _arg4 ? -_num : _num; \ 244}) 245 246#endif /* _ABIO32 */ 247 248#ifndef NOLIBC_NO_RUNTIME 249/* startup code, note that it's called __start on MIPS */ 250void __start(void); 251void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __start(void) 252{ 253 __asm__ volatile ( 254 "move $a0, $sp\n" /* save stack pointer to $a0, as arg1 of _start_c */ 255#if defined(_ABIO32) 256 "addiu $sp, $sp, -16\n" /* the callee expects to save a0..a3 there */ 257#endif /* _ABIO32 */ 258 "lui $t9, %hi(_start_c)\n" /* ABI requires current function address in $t9 */ 259 "ori $t9, %lo(_start_c)\n" 260#if defined(_ABI64) 261 "lui $t0, %highest(_start_c)\n" 262 "ori $t0, %higher(_start_c)\n" 263 "dsll $t0, 0x20\n" 264 "or $t9, $t0\n" 265#endif /* _ABI64 */ 266 "jalr $t9\n" /* transfer to c runtime */ 267 ); 268 __nolibc_entrypoint_epilogue(); 269} 270#endif /* NOLIBC_NO_RUNTIME */ 271 272#endif /* _NOLIBC_ARCH_MIPS_H */
~/
Read-only file preview.