libgloss/xtensa/syscalls.c

   1 /*
   2  * Copyright (C) 2023 Espressif Systems (Shanghai) CO LTD
   3  * SPDX-License-Identifier: BSD-2-Clause
   4  */
   5
   6 #include <unistd.h>
   7 #include <syscalls.h>
   8 #include <sys/stat.h>
   9 #include <soc/uart.h>
  10
  11 #if defined (OPENOCD_SEMIHOSTING) || (QEMU_SEMIHOSTING)
  12 # define WITH_SEMIHOSTING
  13 # define __WEAK_FUNCTION_ATTR__
  14 #else
  15 # define __WEAK_FUNCTION_ATTR__ __attribute__((__weak__))
  16 #endif
  17
  18
  19 /* __semihosting_call is a function in case semihosting usage, macro (-1) otherwise */
  20 #ifdef WITH_SEMIHOSTING
  21
  22 static inline int
  23 __attribute__ ((always_inline))
  24 __semihosting_call(int id, int arg1, int arg2, int arg3, int arg4)
  25 {
  26 # ifdef OPENOCD_SEMIHOSTING
  27     register long a2 asm("a2") = id;
  28     long args[] = {arg1, arg2, arg3, arg4};
  29     register long a3 asm("a3") = (long)&args;
  30
  31     /* OpenOCD has different semihosting api for sys_exit on 32-bit and 64-bit */
  32     if (id == SYS_exit && sizeof(void *) != 8) {
  33         a3 = ADP_STOPPED_APPLICATION_EXIT;
  34     }
  35     __asm__  __volatile__ (
  36         "break 1, 14\n"
  37         : "+r"(a2): "r"(a3)
  38         : "memory");
  39
  40     // return code is placed in a2 register, so return it to the caller
  41     return a2;
  42 # else // OPENOCD_SEMIHOSTING
  43     extern int __sim_call(int id, int arg1, int arg2, int arg3, int arg4);
  44     return __sim_call(id, arg1, arg2, arg3, arg4);
  45 # endif // OPENOCD_SEMIHOSTING
  46 }
  47
  48 # ifdef OPENOCD_SEMIHOSTING
  49
  50 int
  51 __semihosting_init (void)
  52 {
  53     struct {
  54         int version;
  55     } ver_info = { 2 };
  56     __semihosting_call(ESP_SEMIHOSTING_SYS_DRV_INFO, (long) &ver_info, sizeof(ver_info), 0, 0);
  57 }
  58
  59 # endif // OPENOCD_SEMIHOSTING
  60
  61 #else // !WITH_SEMIHOSTING
  62 # define __semihosting_call(...) (-1)
  63 #endif // WITH_SEMIHOSTING
  64
  65
  66 void
  67 __WEAK_FUNCTION_ATTR__
  68 __attribute__ ((noreturn))
  69 _exit (int status)
  70 {
  71     __semihosting_call(SYS_exit, status, 0, 0, 0);
  72
  73     for (;;) {
  74         ;
  75     }
  76 }
  77
  78
  79 int
  80 __WEAK_FUNCTION_ATTR__
  81 _open (const char *file, int flags, int mode)
  82 {
  83     return __semihosting_call(SYS_open, (int) file, flags, mode, 0);
  84 }
  85
  86
  87 int
  88 __WEAK_FUNCTION_ATTR__
  89 _lseek (int fd, _off_t off, int whence)
  90 {
  91     return __semihosting_call(SYS_lseek, fd, off, whence, 0);
  92 }
  93
  94
  95 int
  96 __WEAK_FUNCTION_ATTR__
  97 _close (int fd)
  98 {
  99     return __semihosting_call(SYS_close, fd, 0, 0, 0);
 100 }
 101
 102
 103 _ssize_t
 104 __WEAK_FUNCTION_ATTR__
 105 _write (int fd, const char *buf, size_t cnt)
 106 {
 107     int ret = 0;
 108 #ifdef WITH_SEMIHOSTING
 109     ret = __semihosting_call(SYS_write, fd, (int) buf, cnt, 0);
 110 # ifdef OPENOCD_SEMIHOSTING
 111     /* ret - number of bytes that are NOT written. Calculate written */
 112     ret = cnt - ret;
 113 # endif // OPENOCD_SEMIHOSTING
 114 #else // !WITH_SEMIHOSTING
 115     if (fd != STDOUT_FILENO && fd != STDERR_FILENO) {
 116         return -1;
 117     }
 118
 119     for (uint32_t i = 0; i < cnt; i++) {
 120         board_uart_write_char(buf[i]);
 121     }
 122     ret = cnt;
 123 #endif // WITH_SEMIHOSTING
 124     return ret;
 125 }
 126
 127
 128 /* Do not compile functions with common implementation
 129  * if building semihosting library
 130  */
 131 #ifndef WITH_SEMIHOSTING
 132
 133 struct _reent*
 134 __WEAK_FUNCTION_ATTR__
 135 __getreent(void)
 136 {
 137     return _GLOBAL_REENT;
 138 }
 139
 140
 141 int
 142 __WEAK_FUNCTION_ATTR__
 143 _fstat (int fd, struct stat *pstat)
 144 {
 145
 146     if (fd < STDERR_FILENO)
 147     {
 148         pstat->st_mode = S_IFCHR;
 149         return  0;
 150     }
 151     return  -1;
 152 }
 153
 154
 155 _ssize_t
 156 __WEAK_FUNCTION_ATTR__
 157 _read (int fd, char *buf, size_t cnt)
 158 {
 159     return -1;
 160 }
 161
 162
 163 int
 164 __WEAK_FUNCTION_ATTR__
 165 _getpid (void)
 166 {
 167     return -1;
 168 }
 169
 170
 171 int
 172 __WEAK_FUNCTION_ATTR__
 173 _kill (int sig)
 174 {
 175     return -1;
 176 }
 177
 178
 179 void *
 180 __WEAK_FUNCTION_ATTR__
 181 _sbrk (int incr)
 182 {
 183     extern char   end; /* Set by linker.  */
 184     static char * heap_end;
 185     char *        prev_heap_end;
 186
 187     if (heap_end == 0) {
 188         heap_end = & end;
 189     }
 190
 191     prev_heap_end = heap_end;
 192     heap_end += incr;
 193
 194     return (void *) prev_heap_end;
 195 }
 196
 197
 198 int
 199 __WEAK_FUNCTION_ATTR__
 200 pthread_setcancelstate (int state, int *oldstate)
 201 {
 202     return 0;
 203 }
 204
 205 #endif // WITH_SEMIHOSTING