1 /* SPDX-License-Identifier: LGPL-2.1 OR MIT */ 2 /* 3 * OpenRISC specific definitions for NOLIBC 4 * Copyright (C) 2026 Thomas Weißschuh <linux@weissschuh.net> 5 */ 6 7 #ifndef _NOLIBC_ARCH_OPENRISC_H 8 #define _NOLIBC_ARCH_OPENRISC_H 9 10 #include "compiler.h" 11 #include "crt.h" 12 13 /* 14 * Syscalls for OpenRISC: 15 * - syscall number is passed in r11 16 * - arguments are in r3, r4, r5, r6, r7, r8 17 * - the system call is performed by calling l.sys 1 18 * - syscall return value is in r11 19 */ 20 21 #define _NOLIBC_SYSCALL_CLOBBERLIST \ 22 "r12", "r13", "r15", "r17", "r19", "r21", "r23", "r25", "r27", "r29", "r31", "memory" 23 24 #define __nolibc_syscall0(num) \ 25 ({ \ 26 register long _num __asm__ ("r11") = (num); \ 27 \ 28 __asm__ volatile ( \ 29 "l.sys 1\n" \ 30 : "+r"(_num) \ 31 : \ 32 : "r3", "r4", "r5", "r6", "r7", "r8", \ 33 _NOLIBC_SYSCALL_CLOBBERLIST \ 34 ); \ 35 _num; \ 36 }) 37 38 #define __nolibc_syscall1(num, arg1) \ 39 ({ \ 40 register long _num __asm__ ("r11") = (num); \ 41 register long _arg1 __asm__ ("r3") = (long)(arg1); \ 42 \ 43 __asm__ volatile ( \ 44 "l.sys 1\n" \ 45 : "+r"(_num) \ 46 : "r"(_arg1) \ 47 : "r4", "r5", "r6", "r7", "r8", _NOLIBC_SYSCALL_CLOBBERLIST \ 48 ); \ 49 _num; \ 50 }) 51 52 #define __nolibc_syscall2(num, arg1, arg2) \ 53 ({ \ 54 register long _num __asm__ ("r11") = (num); \ 55 register long _arg1 __asm__ ("r3") = (long)(arg1); \ 56 register long _arg2 __asm__ ("r4") = (long)(arg2); \ 57 \ 58 __asm__ volatile ( \ 59 "l.sys 1\n" \ 60 : "+r"(_num) \ 61 : "r"(_arg1), "r"(_arg2) \ 62 : "r5", "r6", "r7", "r8", _NOLIBC_SYSCALL_CLOBBERLIST \ 63 ); \ 64 _num; \ 65 }) 66 67 #define __nolibc_syscall3(num, arg1, arg2, arg3) \ 68 ({ \ 69 register long _num __asm__ ("r11") = (num); \ 70 register long _arg1 __asm__ ("r3") = (long)(arg1); \ 71 register long _arg2 __asm__ ("r4") = (long)(arg2); \ 72 register long _arg3 __asm__ ("r5") = (long)(arg3); \ 73 \ 74 __asm__ volatile ( \ 75 "l.sys 1\n" \ 76 : "+r"(_num) \ 77 : "r"(_arg1), "r"(_arg2), "r"(_arg3) \ 78 : "r6", "r7", "r8", _NOLIBC_SYSCALL_CLOBBERLIST \ 79 ); \ 80 _num; \ 81 }) 82 83 #define __nolibc_syscall4(num, arg1, arg2, arg3, arg4) \ 84 ({ \ 85 register long _num __asm__ ("r11") = (num); \ 86 register long _arg1 __asm__ ("r3") = (long)(arg1); \ 87 register long _arg2 __asm__ ("r4") = (long)(arg2); \ 88 register long _arg3 __asm__ ("r5") = (long)(arg3); \ 89 register long _arg4 __asm__ ("r6") = (long)(arg4); \ 90 \ 91 __asm__ volatile ( \ 92 "l.sys 1\n" \ 93 : "+r"(_num) \ 94 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ 95 : "r7", "r8", _NOLIBC_SYSCALL_CLOBBERLIST \ 96 ); \ 97 _num; \ 98 }) 99 100 #define __nolibc_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ 101 ({ \ 102 register long _num __asm__ ("r11") = (num); \ 103 register long _arg1 __asm__ ("r3") = (long)(arg1); \ 104 register long _arg2 __asm__ ("r4") = (long)(arg2); \ 105 register long _arg3 __asm__ ("r5") = (long)(arg3); \ 106 register long _arg4 __asm__ ("r6") = (long)(arg4); \ 107 register long _arg5 __asm__ ("r7") = (long)(arg5); \ 108 \ 109 __asm__ volatile ( \ 110 "l.sys 1\n" \ 111 : "+r"(_num) \ 112 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ 113 : "r8", _NOLIBC_SYSCALL_CLOBBERLIST \ 114 ); \ 115 _num; \ 116 }) 117 118 #define __nolibc_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ 119 ({ \ 120 register long _num __asm__ ("r11") = (num); \ 121 register long _arg1 __asm__ ("r3") = (long)(arg1); \ 122 register long _arg2 __asm__ ("r4") = (long)(arg2); \ 123 register long _arg3 __asm__ ("r5") = (long)(arg3); \ 124 register long _arg4 __asm__ ("r6") = (long)(arg4); \ 125 register long _arg5 __asm__ ("r7") = (long)(arg5); \ 126 register long _arg6 __asm__ ("r8") = (long)(arg6); \ 127 \ 128 __asm__ volatile ( \ 129 "l.sys 1\n" \ 130 : "+r"(_num) \ 131 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ 132 "r"(_arg6) \ 133 : _NOLIBC_SYSCALL_CLOBBERLIST \ 134 ); \ 135 _num; \ 136 }) 137 138 #ifndef NOLIBC_NO_RUNTIME 139 /* startup code */ 140 void _start_wrapper(void); 141 void __attribute__((weak,noreturn)) 142 __nolibc_entrypoint __nolibc_no_stack_protector 143 _start_wrapper(void) 144 { 145 __asm__ volatile ( 146 ".global _start\n" /* The C function will have a prologue, */ 147 ".type _start, @function\n" /* corrupting "sp/r1" */ 148 ".weak _start\n" 149 "_start:\n" 150 151 "l.jal _start_c\n" /* transfer to c runtime */ 152 "l.or r3,r1,r1\n" /* save stack pointer to r3, as arg1 of _start_c */ 153 154 ".size _start, .-_start\n" 155 ); 156 __nolibc_entrypoint_epilogue(); 157 } 158 #endif /* NOLIBC_NO_RUNTIME */ 159 160 #endif /* _NOLIBC_ARCH_OPENRISC_H */ 161