| /* SPDX-License-Identifier: LGPL-2.1 OR MIT */ |
| /* |
| * PowerPC specific definitions for NOLIBC |
| * Copyright (C) 2023 Zhangjin Wu <falcon@tinylab.org> |
| */ |
| |
| #ifndef _NOLIBC_ARCH_POWERPC_H |
| #define _NOLIBC_ARCH_POWERPC_H |
| |
| #include "compiler.h" |
| #include "crt.h" |
| |
| /* Syscalls for PowerPC : |
| * - stack is 16-byte aligned |
| * - syscall number is passed in r0 |
| * - arguments are in r3, r4, r5, r6, r7, r8, r9 |
| * - the system call is performed by calling "sc" |
| * - syscall return comes in r3, and the summary overflow bit is checked |
| * to know if an error occurred, in which case errno is in r3. |
| * - 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 _NOLIBC_SYSCALL_CLOBBERLIST \ |
| "memory", "cr0", "r12", "r11", "r10", "r9" |
| |
| #define my_syscall0(num) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num) \ |
| : \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST, "r8", "r7", "r6", "r5", "r4" \ |
| ); \ |
| _ret; \ |
| }) |
| |
| #define my_syscall1(num, arg1) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| register long _arg1 __asm__ ("r3") = (long)(arg1); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num) \ |
| : "0"(_arg1) \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST, "r8", "r7", "r6", "r5", "r4" \ |
| ); \ |
| _ret; \ |
| }) |
| |
| |
| #define my_syscall2(num, arg1, arg2) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| register long _arg1 __asm__ ("r3") = (long)(arg1); \ |
| register long _arg2 __asm__ ("r4") = (long)(arg2); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num), "+r"(_arg2) \ |
| : "0"(_arg1) \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST, "r8", "r7", "r6", "r5" \ |
| ); \ |
| _ret; \ |
| }) |
| |
| |
| #define my_syscall3(num, arg1, arg2, arg3) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| register long _arg1 __asm__ ("r3") = (long)(arg1); \ |
| register long _arg2 __asm__ ("r4") = (long)(arg2); \ |
| register long _arg3 __asm__ ("r5") = (long)(arg3); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num), "+r"(_arg2), "+r"(_arg3) \ |
| : "0"(_arg1) \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST, "r8", "r7", "r6" \ |
| ); \ |
| _ret; \ |
| }) |
| |
| |
| #define my_syscall4(num, arg1, arg2, arg3, arg4) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| register long _arg1 __asm__ ("r3") = (long)(arg1); \ |
| register long _arg2 __asm__ ("r4") = (long)(arg2); \ |
| register long _arg3 __asm__ ("r5") = (long)(arg3); \ |
| register long _arg4 __asm__ ("r6") = (long)(arg4); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num), "+r"(_arg2), "+r"(_arg3), \ |
| "+r"(_arg4) \ |
| : "0"(_arg1) \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST, "r8", "r7" \ |
| ); \ |
| _ret; \ |
| }) |
| |
| |
| #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| register long _arg1 __asm__ ("r3") = (long)(arg1); \ |
| register long _arg2 __asm__ ("r4") = (long)(arg2); \ |
| register long _arg3 __asm__ ("r5") = (long)(arg3); \ |
| register long _arg4 __asm__ ("r6") = (long)(arg4); \ |
| register long _arg5 __asm__ ("r7") = (long)(arg5); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num), "+r"(_arg2), "+r"(_arg3), \ |
| "+r"(_arg4), "+r"(_arg5) \ |
| : "0"(_arg1) \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST, "r8" \ |
| ); \ |
| _ret; \ |
| }) |
| |
| #define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ |
| ({ \ |
| register long _ret __asm__ ("r3"); \ |
| register long _num __asm__ ("r0") = (num); \ |
| register long _arg1 __asm__ ("r3") = (long)(arg1); \ |
| register long _arg2 __asm__ ("r4") = (long)(arg2); \ |
| register long _arg3 __asm__ ("r5") = (long)(arg3); \ |
| register long _arg4 __asm__ ("r6") = (long)(arg4); \ |
| register long _arg5 __asm__ ("r7") = (long)(arg5); \ |
| register long _arg6 __asm__ ("r8") = (long)(arg6); \ |
| \ |
| __asm__ volatile ( \ |
| " sc\n" \ |
| " bns+ 1f\n" \ |
| " neg %0, %0\n" \ |
| "1:\n" \ |
| : "=r"(_ret), "+r"(_num), "+r"(_arg2), "+r"(_arg3), \ |
| "+r"(_arg4), "+r"(_arg5), "+r"(_arg6) \ |
| : "0"(_arg1) \ |
| : _NOLIBC_SYSCALL_CLOBBERLIST \ |
| ); \ |
| _ret; \ |
| }) |
| |
| #ifndef __powerpc64__ |
| /* FIXME: For 32-bit PowerPC, with newer gcc compilers (e.g. gcc 13.1.0), |
| * "omit-frame-pointer" fails with __attribute__((no_stack_protector)) but |
| * works with __attribute__((__optimize__("-fno-stack-protector"))) |
| */ |
| #ifdef __no_stack_protector |
| #undef __no_stack_protector |
| #define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector"))) |
| #endif |
| #endif /* !__powerpc64__ */ |
| |
| /* startup code */ |
| void __attribute__((weak, noreturn, optimize("Os", "omit-frame-pointer"))) __no_stack_protector _start(void) |
| { |
| #ifdef __powerpc64__ |
| #if _CALL_ELF == 2 |
| /* with -mabi=elfv2, save TOC/GOT pointer to r2 |
| * r12 is global entry pointer, we use it to compute TOC from r12 |
| * https://www.llvm.org/devmtg/2014-04/PDFs/Talks/Euro-LLVM-2014-Weigand.pdf |
| * https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.pdf |
| */ |
| __asm__ volatile ( |
| "addis 2, 12, .TOC. - _start@ha\n" |
| "addi 2, 2, .TOC. - _start@l\n" |
| ); |
| #endif /* _CALL_ELF == 2 */ |
| |
| __asm__ volatile ( |
| "mr 3, 1\n" /* save stack pointer to r3, as arg1 of _start_c */ |
| "clrrdi 1, 1, 4\n" /* align the stack to 16 bytes */ |
| "li 0, 0\n" /* zero the frame pointer */ |
| "stdu 1, -32(1)\n" /* the initial stack frame */ |
| "bl _start_c\n" /* transfer to c runtime */ |
| ); |
| #else |
| __asm__ volatile ( |
| "mr 3, 1\n" /* save stack pointer to r3, as arg1 of _start_c */ |
| "clrrwi 1, 1, 4\n" /* align the stack to 16 bytes */ |
| "li 0, 0\n" /* zero the frame pointer */ |
| "stwu 1, -16(1)\n" /* the initial stack frame */ |
| "bl _start_c\n" /* transfer to c runtime */ |
| ); |
| #endif |
| __builtin_unreachable(); |
| } |
| |
| #endif /* _NOLIBC_ARCH_POWERPC_H */ |
