tools/include/nolibc/arch-riscv.h

   1 /* SPDX-License-Identifier: LGPL-2.1 OR MIT */
   2 /*
   3  * RISCV (32 and 64) specific definitions for NOLIBC
   4  * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
   5  */
   6
   7 #ifndef _NOLIBC_ARCH_RISCV_H
   8 #define _NOLIBC_ARCH_RISCV_H
   9
  10 /* O_* macros for fcntl/open are architecture-specific */
  11 #define O_RDONLY            0
  12 #define O_WRONLY            1
  13 #define O_RDWR              2
  14 #define O_CREAT         0x100
  15 #define O_EXCL          0x200
  16 #define O_NOCTTY        0x400
  17 #define O_TRUNC        0x1000
  18 #define O_APPEND       0x2000
  19 #define O_NONBLOCK     0x4000
  20 #define O_DIRECTORY  0x200000
  21
  22 struct sys_stat_struct {
  23         unsigned long   st_dev;         /* Device.  */
  24         unsigned long   st_ino;         /* File serial number.  */
  25         unsigned int    st_mode;        /* File mode.  */
  26         unsigned int    st_nlink;       /* Link count.  */
  27         unsigned int    st_uid;         /* User ID of the file's owner.  */
  28         unsigned int    st_gid;         /* Group ID of the file's group. */
  29         unsigned long   st_rdev;        /* Device number, if device.  */
  30         unsigned long   __pad1;
  31         long            st_size;        /* Size of file, in bytes.  */
  32         int             st_blksize;     /* Optimal block size for I/O.  */
  33         int             __pad2;
  34         long            st_blocks;      /* Number 512-byte blocks allocated. */
  35         long            st_atime;       /* Time of last access.  */
  36         unsigned long   st_atime_nsec;
  37         long            st_mtime;       /* Time of last modification.  */
  38         unsigned long   st_mtime_nsec;
  39         long            st_ctime;       /* Time of last status change.  */
  40         unsigned long   st_ctime_nsec;
  41         unsigned int    __unused4;
  42         unsigned int    __unused5;
  43 };
  44
  45 #if   __riscv_xlen == 64
  46 #define PTRLOG "3"
  47 #define SZREG  "8"
  48 #elif __riscv_xlen == 32
  49 #define PTRLOG "2"
  50 #define SZREG  "4"
  51 #endif
  52
  53 /* Syscalls for RISCV :
  54  *   - stack is 16-byte aligned
  55  *   - syscall number is passed in a7
  56  *   - arguments are in a0, a1, a2, a3, a4, a5
  57  *   - the system call is performed by calling ecall
  58  *   - syscall return comes in a0
  59  *   - the arguments are cast to long and assigned into the target
  60  *     registers which are then simply passed as registers to the asm code,
  61  *     so that we don't have to experience issues with register constraints.
  62  *
  63  * On riscv, select() is not implemented so we have to use pselect6().
  64  */
  65 #define __ARCH_WANT_SYS_PSELECT6
  66
  67 #define my_syscall0(num)                                                      \
  68 ({                                                                            \
  69         register long _num  asm("a7") = (num);                                \
  70         register long _arg1 asm("a0");                                        \
  71                                                                               \
  72         asm volatile (                                                        \
  73                 "ecall\n\t"                                                   \
  74                 : "=r"(_arg1)                                                 \
  75                 : "r"(_num)                                                   \
  76                 : "memory", "cc"                                              \
  77         );                                                                    \
  78         _arg1;                                                                \
  79 })
  80
  81 #define my_syscall1(num, arg1)                                                \
  82 ({                                                                            \
  83         register long _num  asm("a7") = (num);                                \
  84         register long _arg1 asm("a0") = (long)(arg1);                         \
  85                                                                               \
  86         asm volatile (                                                        \
  87                 "ecall\n"                                                     \
  88                 : "+r"(_arg1)                                                 \
  89                 : "r"(_num)                                                   \
  90                 : "memory", "cc"                                              \
  91         );                                                                    \
  92         _arg1;                                                                \
  93 })
  94
  95 #define my_syscall2(num, arg1, arg2)                                          \
  96 ({                                                                            \
  97         register long _num  asm("a7") = (num);                                \
  98         register long _arg1 asm("a0") = (long)(arg1);                         \
  99         register long _arg2 asm("a1") = (long)(arg2);                         \
 100                                                                               \
 101         asm volatile (                                                        \
 102                 "ecall\n"                                                     \
 103                 : "+r"(_arg1)                                                 \
 104                 : "r"(_arg2),                                                 \
 105                   "r"(_num)                                                   \
 106                 : "memory", "cc"                                              \
 107         );                                                                    \
 108         _arg1;                                                                \
 109 })
 110
 111 #define my_syscall3(num, arg1, arg2, arg3)                                    \
 112 ({                                                                            \
 113         register long _num  asm("a7") = (num);                                \
 114         register long _arg1 asm("a0") = (long)(arg1);                         \
 115         register long _arg2 asm("a1") = (long)(arg2);                         \
 116         register long _arg3 asm("a2") = (long)(arg3);                         \
 117                                                                               \
 118         asm volatile (                                                        \
 119                 "ecall\n\t"                                                   \
 120                 : "+r"(_arg1)                                                 \
 121                 : "r"(_arg2), "r"(_arg3),                                     \
 122                   "r"(_num)                                                   \
 123                 : "memory", "cc"                                              \
 124         );                                                                    \
 125         _arg1;                                                                \
 126 })
 127
 128 #define my_syscall4(num, arg1, arg2, arg3, arg4)                              \
 129 ({                                                                            \
 130         register long _num  asm("a7") = (num);                                \
 131         register long _arg1 asm("a0") = (long)(arg1);                         \
 132         register long _arg2 asm("a1") = (long)(arg2);                         \
 133         register long _arg3 asm("a2") = (long)(arg3);                         \
 134         register long _arg4 asm("a3") = (long)(arg4);                         \
 135                                                                               \
 136         asm volatile (                                                        \
 137                 "ecall\n"                                                     \
 138                 : "+r"(_arg1)                                                 \
 139                 : "r"(_arg2), "r"(_arg3), "r"(_arg4),                         \
 140                   "r"(_num)                                                   \
 141                 : "memory", "cc"                                              \
 142         );                                                                    \
 143         _arg1;                                                                \
 144 })
 145
 146 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5)                        \
 147 ({                                                                            \
 148         register long _num  asm("a7") = (num);                                \
 149         register long _arg1 asm("a0") = (long)(arg1);                         \
 150         register long _arg2 asm("a1") = (long)(arg2);                         \
 151         register long _arg3 asm("a2") = (long)(arg3);                         \
 152         register long _arg4 asm("a3") = (long)(arg4);                         \
 153         register long _arg5 asm("a4") = (long)(arg5);                         \
 154                                                                               \
 155         asm volatile (                                                        \
 156                 "ecall\n"                                                     \
 157                 : "+r"(_arg1)                                                 \
 158                 : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5),             \
 159                   "r"(_num)                                                   \
 160                 : "memory", "cc"                                              \
 161         );                                                                    \
 162         _arg1;                                                                \
 163 })
 164
 165 #define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6)                  \
 166 ({                                                                            \
 167         register long _num  asm("a7") = (num);                                \
 168         register long _arg1 asm("a0") = (long)(arg1);                         \
 169         register long _arg2 asm("a1") = (long)(arg2);                         \
 170         register long _arg3 asm("a2") = (long)(arg3);                         \
 171         register long _arg4 asm("a3") = (long)(arg4);                         \
 172         register long _arg5 asm("a4") = (long)(arg5);                         \
 173         register long _arg6 asm("a5") = (long)(arg6);                         \
 174                                                                               \
 175         asm volatile (                                                        \
 176                 "ecall\n"                                                     \
 177                 : "+r"(_arg1)                                                 \
 178                 : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), "r"(_arg6), \
 179                   "r"(_num)                                                   \
 180                 : "memory", "cc"                                              \
 181         );                                                                    \
 182         _arg1;                                                                \
 183 })
 184
 185 /* startup code */
 186 asm(".section .text\n"
 187     ".weak _start\n"
 188     ".global _start\n"
 189     "_start:\n"
 190     ".option push\n"
 191     ".option norelax\n"
 192     "lla   gp, __global_pointer$\n"
 193     ".option pop\n"
 194     "ld    a0, 0(sp)\n"          // argc (a0) was in the stack
 195     "add   a1, sp, "SZREG"\n"    // argv (a1) = sp
 196     "slli  a2, a0, "PTRLOG"\n"   // envp (a2) = SZREG*argc ...
 197     "add   a2, a2, "SZREG"\n"    //             + SZREG (skip null)
 198     "add   a2,a2,a1\n"           //             + argv
 199     "andi  sp,a1,-16\n"          // sp must be 16-byte aligned
 200     "call  main\n"               // main() returns the status code, we'll exit with it.
 201     "li a7, 93\n"                // NR_exit == 93
 202     "ecall\n"
 203     "");
 204
 205 #endif // _NOLIBC_ARCH_RISCV_H