/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ /* * RISCV (32 and 64) specific definitions for NOLIBC * Copyright (C) 2017-2022 Willy Tarreau */ #ifndef _NOLIBC_ARCH_RISCV_H #define _NOLIBC_ARCH_RISCV_H #include "compiler.h" struct sys_stat_struct { unsigned long st_dev; /* Device. */ unsigned long st_ino; /* File serial number. */ unsigned int st_mode; /* File mode. */ unsigned int st_nlink; /* Link count. */ unsigned int st_uid; /* User ID of the file's owner. */ unsigned int st_gid; /* Group ID of the file's group. */ unsigned long st_rdev; /* Device number, if device. */ unsigned long __pad1; long st_size; /* Size of file, in bytes. */ int st_blksize; /* Optimal block size for I/O. */ int __pad2; long st_blocks; /* Number 512-byte blocks allocated. */ long st_atime; /* Time of last access. */ unsigned long st_atime_nsec; long st_mtime; /* Time of last modification. */ unsigned long st_mtime_nsec; long st_ctime; /* Time of last status change. */ unsigned long st_ctime_nsec; unsigned int __unused4; unsigned int __unused5; }; #if __riscv_xlen == 64 #define PTRLOG "3" #define SZREG "8" #define REG_L "ld" #define REG_S "sd" #elif __riscv_xlen == 32 #define PTRLOG "2" #define SZREG "4" #define REG_L "lw" #define REG_S "sw" #endif /* 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. * * On riscv, 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 ( \ "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; \ }) char **environ __attribute__((weak)); const unsigned long *_auxv __attribute__((weak)); /* startup code */ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void) { __asm__ volatile ( ".option push\n" ".option norelax\n" "lla gp, __global_pointer$\n" ".option pop\n" #ifdef _NOLIBC_STACKPROTECTOR "call __stack_chk_init\n" /* initialize stack protector */ #endif REG_L" a0, 0(sp)\n" /* argc (a0) was in the stack */ "add a1, sp, "SZREG"\n" /* argv (a1) = sp */ "slli a2, a0, "PTRLOG"\n" /* envp (a2) = SZREG*argc ... */ "add a2, a2, "SZREG"\n" /* + SZREG (skip null) */ "add a2,a2,a1\n" /* + argv */ "add a3, a2, zero\n" /* iterate a3 over envp to find auxv (after NULL) */ "0:\n" /* do { */ REG_L" a4, 0(a3)\n" /* a4 = *a3; */ "add a3, a3, "SZREG"\n" /* a3 += sizeof(void*); */ "bne a4, zero, 0b\n" /* } while (a4); */ "lui a4, %hi(_auxv)\n" /* a4 = &_auxv (high bits) */ REG_S" a3, %lo(_auxv)(a4)\n" /* store a3 into _auxv */ "lui a3, %hi(environ)\n" /* a3 = &environ (high bits) */ REG_S" a2,%lo(environ)(a3)\n"/* store envp(a2) into environ */ "andi sp,a1,-16\n" /* sp must be 16-byte aligned */ "call main\n" /* main() returns the status code, we'll exit with it. */ "li a7, 93\n" /* NR_exit == 93 */ "ecall\n" ); __builtin_unreachable(); } #endif /* _NOLIBC_ARCH_RISCV_H */