diff options
| -rw-r--r-- | tools/include/nolibc/nolibc.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h index 1708e9f9f8aa..2551e9b71167 100644 --- a/tools/include/nolibc/nolibc.h +++ b/tools/include/nolibc/nolibc.h @@ -1243,6 +1243,200 @@ struct sys_stat_struct { long st_pad4[14]; }; +#elif defined(__riscv) + +#if __riscv_xlen == 64 +#define PTRLOG "3" +#define SZREG "8" +#elif __riscv_xlen == 32 +#define PTRLOG "2" +#define SZREG "4" +#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. + */ + +#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 */ +asm(".section .text\n" + ".global _start\n" + "_start:\n" + ".option push\n" + ".option norelax\n" + "lla gp, __global_pointer$\n" + ".option pop\n" + "ld 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 + "andi sp,a1,-16\n" // sp must be 16-byte aligned + "call main\n" // main() returns the status code, we'll exit with it. + "andi a0, a0, 0xff\n" // limit exit code to 8 bits + "li a7, 93\n" // NR_exit == 93 + "ecall\n" + ""); + +/* fcntl / open */ +#define O_RDONLY 0 +#define O_WRONLY 1 +#define O_RDWR 2 +#define O_CREAT 0x100 +#define O_EXCL 0x200 +#define O_NOCTTY 0x400 +#define O_TRUNC 0x1000 +#define O_APPEND 0x2000 +#define O_NONBLOCK 0x4000 +#define O_DIRECTORY 0x200000 + +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; +}; + #endif |