| /* SPDX-License-Identifier: LGPL-2.1 OR MIT */ |
| /* |
| * LoongArch specific definitions for NOLIBC |
| * Copyright (C) 2023 Loongson Technology Corporation Limited |
| */ |
| |
| #ifndef _NOLIBC_ARCH_LOONGARCH_H |
| #define _NOLIBC_ARCH_LOONGARCH_H |
| |
| /* Syscalls for LoongArch : |
| * - stack is 16-byte aligned |
| * - syscall number is passed in a7 |
| * - arguments are in a0, a1, a2, a3, a4, a5 |
| * - the system call is performed by calling "syscall 0" |
| * - syscall return comes in a0 |
| * - 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. |
| * |
| * On LoongArch, select() is not implemented so we have to use pselect6(). |
| */ |
| #define __ARCH_WANT_SYS_PSELECT6 |
| |
| #define my_syscall0(num) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (num); \ |
| register long _arg1 __asm__ ("a0"); \ |
| \ |
| __asm__ volatile ( \ |
| "syscall 0\n" \ |
| : "=r"(_arg1) \ |
| : "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| #define my_syscall1(num, arg1) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| \ |
| __asm__ volatile ( \ |
| "syscall 0\n" \ |
| : "+r"(_arg1) \ |
| : "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| #define my_syscall2(num, arg1, arg2) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| \ |
| __asm__ volatile ( \ |
| "syscall 0\n" \ |
| : "+r"(_arg1) \ |
| : "r"(_arg2), \ |
| "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| #define my_syscall3(num, arg1, arg2, arg3) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| register long _arg3 __asm__ ("a2") = (long)(arg3); \ |
| \ |
| __asm__ volatile ( \ |
| "syscall 0\n" \ |
| : "+r"(_arg1) \ |
| : "r"(_arg2), "r"(_arg3), \ |
| "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| #define my_syscall4(num, arg1, arg2, arg3, arg4) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (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 ( \ |
| "syscall 0\n" \ |
| : "+r"(_arg1) \ |
| : "r"(_arg2), "r"(_arg3), "r"(_arg4), \ |
| "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (num); \ |
| register long _arg1 __asm__ ("a0") = (long)(arg1); \ |
| register long _arg2 __asm__ ("a1") = (long)(arg2); \ |
| register long _arg3 __asm__ ("a2") = (long)(arg3); \ |
| register long _arg4 __asm__ ("a3") = (long)(arg4); \ |
| register long _arg5 __asm__ ("a4") = (long)(arg5); \ |
| \ |
| __asm__ volatile ( \ |
| "syscall 0\n" \ |
| : "+r"(_arg1) \ |
| : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ |
| "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| #define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ |
| ({ \ |
| register long _num __asm__ ("a7") = (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 __asm__ ("a4") = (long)(arg5); \ |
| register long _arg6 __asm__ ("a5") = (long)(arg6); \ |
| \ |
| __asm__ volatile ( \ |
| "syscall 0\n" \ |
| : "+r"(_arg1) \ |
| : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), "r"(_arg6), \ |
| "r"(_num) \ |
| : "memory", "$t0", "$t1", "$t2", "$t3", \ |
| "$t4", "$t5", "$t6", "$t7", "$t8" \ |
| ); \ |
| _arg1; \ |
| }) |
| |
| char **environ __attribute__((weak)); |
| const unsigned long *_auxv __attribute__((weak)); |
| |
| #if __loongarch_grlen == 32 |
| #define LONGLOG "2" |
| #define SZREG "4" |
| #define REG_L "ld.w" |
| #define LONG_S "st.w" |
| #define LONG_ADD "add.w" |
| #define LONG_ADDI "addi.w" |
| #define LONG_SLL "slli.w" |
| #define LONG_BSTRINS "bstrins.w" |
| #else // __loongarch_grlen == 64 |
| #define LONGLOG "3" |
| #define SZREG "8" |
| #define REG_L "ld.d" |
| #define LONG_S "st.d" |
| #define LONG_ADD "add.d" |
| #define LONG_ADDI "addi.d" |
| #define LONG_SLL "slli.d" |
| #define LONG_BSTRINS "bstrins.d" |
| #endif |
| |
| /* startup code */ |
| void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) |
| { |
| __asm__ volatile ( |
| REG_L " $a0, $sp, 0\n" // argc (a0) was in the stack |
| LONG_ADDI " $a1, $sp, "SZREG"\n" // argv (a1) = sp + SZREG |
| LONG_SLL " $a2, $a0, "LONGLOG"\n" // envp (a2) = SZREG*argc ... |
| LONG_ADDI " $a2, $a2, "SZREG"\n" // + SZREG (skip null) |
| LONG_ADD " $a2, $a2, $a1\n" // + argv |
| |
| "move $a3, $a2\n" // iterate a3 over envp to find auxv (after NULL) |
| "0:\n" // do { |
| REG_L " $a4, $a3, 0\n" // a4 = *a3; |
| LONG_ADDI " $a3, $a3, "SZREG"\n" // a3 += sizeof(void*); |
| "bne $a4, $zero, 0b\n" // } while (a4); |
| "la.pcrel $a4, _auxv\n" // a4 = &_auxv |
| LONG_S " $a3, $a4, 0\n" // store a3 into _auxv |
| |
| "la.pcrel $a3, environ\n" // a3 = &environ |
| LONG_S " $a2, $a3, 0\n" // store envp(a2) into environ |
| LONG_BSTRINS " $sp, $zero, 3, 0\n" // sp must be 16-byte aligned |
| "bl main\n" // main() returns the status code, we'll exit with it. |
| "li.w $a7, 93\n" // NR_exit == 93 |
| "syscall 0\n" |
| ); |
| __builtin_unreachable(); |
| } |
| |
| #endif // _NOLIBC_ARCH_LOONGARCH_H |
