| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157 |
- /* SPDX-License-Identifier: LGPL-2.1 OR MIT */
- /*
- * RISCV (32 and 64) specific definitions for NOLIBC
- * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
- */
- #ifndef _NOLIBC_ARCH_RISCV_H
- #define _NOLIBC_ARCH_RISCV_H
- #include "compiler.h"
- #include "crt.h"
- /* Syscalls for RISCV :
- * - 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 ecall
- * - 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.
- */
- #define my_syscall0(num) \
- ({ \
- register long _num __asm__ ("a7") = (num); \
- register long _arg1 __asm__ ("a0"); \
- \
- __asm__ volatile ( \
- "ecall\n\t" \
- : "=r"(_arg1) \
- : "r"(_num) \
- : "memory", "cc" \
- ); \
- _arg1; \
- })
- #define my_syscall1(num, arg1) \
- ({ \
- register long _num __asm__ ("a7") = (num); \
- register long _arg1 __asm__ ("a0") = (long)(arg1); \
- \
- __asm__ volatile ( \
- "ecall\n" \
- : "+r"(_arg1) \
- : "r"(_num) \
- : "memory", "cc" \
- ); \
- _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 ( \
- "ecall\n" \
- : "+r"(_arg1) \
- : "r"(_arg2), \
- "r"(_num) \
- : "memory", "cc" \
- ); \
- _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 ( \
- "ecall\n\t" \
- : "+r"(_arg1) \
- : "r"(_arg2), "r"(_arg3), \
- "r"(_num) \
- : "memory", "cc" \
- ); \
- _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 ( \
- "ecall\n" \
- : "+r"(_arg1) \
- : "r"(_arg2), "r"(_arg3), "r"(_arg4), \
- "r"(_num) \
- : "memory", "cc" \
- ); \
- _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 ( \
- "ecall\n" \
- : "+r"(_arg1) \
- : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
- "r"(_num) \
- : "memory", "cc" \
- ); \
- _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 ( \
- "ecall\n" \
- : "+r"(_arg1) \
- : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), "r"(_arg6), \
- "r"(_num) \
- : "memory", "cc" \
- ); \
- _arg1; \
- })
- /* startup code */
- void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
- {
- __asm__ volatile (
- ".option push\n"
- ".option norelax\n"
- "lla gp, __global_pointer$\n"
- ".option pop\n"
- "mv a0, sp\n" /* save stack pointer to a0, as arg1 of _start_c */
- "andi sp, a0, -16\n" /* sp must be 16-byte aligned */
- "call _start_c\n" /* transfer to c runtime */
- );
- __nolibc_entrypoint_epilogue();
- }
- #endif /* _NOLIBC_ARCH_RISCV_H */
|
