libgloss/tic6x/syscalls.c

   1 /* Copyright (c) 2010 CodeSourcery, Inc.
   2    All rights reserved.
   3
   4    Redistribution and use in source and binary forms, with or without
   5    modification, are permitted provided that the following conditions are met:
   6     * Redistributions of source code must retain the above copyright
   7       notice, this list of conditions and the following disclaimer.
   8     * Redistributions in binary form must reproduce the above copyright
   9       notice, this list of conditions and the following disclaimer in the
  10       documentation and/or other materials provided with the distribution.
  11     * Neither the name of CodeSourcery nor the
  12       names of its contributors may be used to endorse or promote products
  13       derived from this software without specific prior written permission.
  14
  15     THIS SOFTWARE IS PROVIDED BY CODESOURCERY, INC. ``AS IS'' AND ANY
  16     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18     PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CODESOURCERY BE LIABLE
  19     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  20     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  21     OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  22     BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  23     LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  25     USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  26     DAMAGE.  */
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <time.h>
  31 #include <sys/time.h>
  32 #include <sys/stat.h>
  33 #include <errno.h>
  34
  35 #define _DTOPEN 0xf0
  36 #define _DTCLOSE 0xf1
  37 #define _DTREAD 0xf2
  38 #define _DTWRITE 0xf3
  39 #define _DTLSEEK 0xf4
  40 #define _DTUNLINK 0xf5
  41 #define _DTGETENV 0xf6
  42 #define _DTRENAME 0xf7
  43 #define _DTGETTIME 0xf8
  44 #define _DTGETCLK 0xf9
  45 #define _DTSYNC 0xff
  46
  47 #define CIOBUFSIZ (BUFSIZ + 32)
  48
  49 struct __attribute__((packed)) cio_open_to_host
  50 {
  51   /* Suggested file descriptor (little endian).  */
  52   short fd;
  53   /* Flags (little endian).  */
  54   short flags;
  55 };
  56
  57 struct __attribute__((packed)) cio_open_from_host
  58 {
  59   /* File descriptor (little endian).  */
  60   short fd;
  61 };
  62
  63 struct __attribute__((packed)) cio_close_to_host
  64 {
  65   /* File descriptor (little endian).  */
  66   short fd;
  67 };
  68
  69 struct __attribute__((packed)) cio_close_from_host
  70 {
  71   /* Result (little endian).  */
  72   short result;
  73 };
  74
  75 struct __attribute__((packed)) cio_read_to_host
  76 {
  77   /* File descriptor (little endian).  */
  78   short fd;
  79   /* Length (little endian).  */
  80   short length;
  81 };
  82
  83 struct __attribute__((packed)) cio_read_from_host
  84 {
  85   /* Result (little endian).  */
  86   short result;
  87 };
  88
  89 struct __attribute__((packed)) cio_write_to_host
  90 {
  91   /* File descriptor (little endian).  */
  92   short fd;
  93   /* Length (little endian).  */
  94   short length;
  95 };
  96
  97 struct __attribute__((packed)) cio_write_from_host
  98 {
  99   /* Result (little endian).  */
 100   short result;
 101 };
 102
 103 struct __attribute__((packed)) cio_lseek_to_host
 104 {
 105   /* File descriptor (little endian).  */
 106   short fd;
 107   /* Offset (little endian).  */
 108   int offset;
 109   /* Whence (little endian).  */
 110   short whence;
 111 };
 112
 113 struct __attribute__((packed)) cio_lseek_from_host
 114 {
 115   /* Result (little endian).  */
 116   int result;
 117 };
 118
 119 struct __attribute__((packed)) cio_unlink_to_host
 120 {
 121   /* Empty.  */
 122 };
 123
 124 struct __attribute__((packed)) cio_unlink_from_host
 125 {
 126   /* Result (little endian).  */
 127   short result;
 128 };
 129
 130 struct __attribute__((packed)) cio_rename_to_host
 131 {
 132   /* Empty.  */
 133 };
 134
 135 struct __attribute__((packed)) cio_rename_from_host
 136 {
 137   /* Result (little endian).  */
 138   short result;
 139 };
 140
 141 struct __attribute__((packed)) cio_gettime_to_host
 142 {
 143   /* Empty.  */
 144 };
 145
 146 struct __attribute__((packed)) cio_gettime_from_host
 147 {
 148   /* Time (little endian).  */
 149   int time;
 150 };
 151
 152 struct __attribute__((packed)) cio_getclk_to_host
 153 {
 154   /* Empty.  */
 155 };
 156
 157 struct __attribute__((packed)) cio_getclk_from_host
 158 {
 159   /* Clock cycles (little endian).  */
 160   int result;
 161 };
 162
 163 struct __attribute__((packed)) cio_to_host
 164 {
 165   /* Data length (target endian).  */
 166   unsigned int length;
 167   /* Command.  */
 168   unsigned char command;
 169   /* Parameters.  */
 170   union
 171   {
 172     unsigned char buf[8];
 173     struct cio_open_to_host open;
 174     struct cio_close_to_host close;
 175     struct cio_read_to_host read;
 176     struct cio_write_to_host write;
 177     struct cio_lseek_to_host lseek;
 178     struct cio_unlink_to_host unlink;
 179     struct cio_rename_to_host rename;
 180     struct cio_gettime_to_host gettime;
 181     struct cio_getclk_to_host getclk;
 182   } parms;
 183   /* Variable-length data.  */
 184   unsigned char data[];
 185 };
 186
 187 struct __attribute__((packed)) cio_from_host
 188 {
 189   /* Length (target endian).  */
 190   unsigned int length;
 191   /* Parameters.  */
 192   union
 193   {
 194     unsigned char buf[8];
 195     struct cio_open_from_host open;
 196     struct cio_close_from_host close;
 197     struct cio_read_from_host read;
 198     struct cio_write_from_host write;
 199     struct cio_lseek_from_host lseek;
 200     struct cio_unlink_from_host unlink;
 201     struct cio_rename_from_host rename;
 202     struct cio_gettime_from_host gettime;
 203     struct cio_getclk_from_host getclk;
 204   } parms;
 205   /* Data.  */
 206   unsigned char data[];
 207 };
 208
 209 union
 210 {
 211   unsigned char buf[CIOBUFSIZ];
 212   int align;
 213   union
 214   {
 215     struct cio_to_host to_host;
 216     struct cio_from_host from_host;
 217   } u;
 218 } _CIOBUF_ __attribute__((section(".cio")));
 219
 220 #ifdef _BIG_ENDIAN
 221 #define SWAPSHORT(s)    ((short)((((s) & 0xff) << 8) | (((s) & 0xff00) >> 8)))
 222 #define SWAPINT(i)      (__builtin_bswap32 (i))
 223 #else
 224 #define SWAPSHORT(s)    (s)
 225 #define SWAPINT(i)      (i)
 226 #endif
 227
 228 static void __attribute__((noinline))
 229 do_semi_call (void)
 230 {
 231   asm volatile (".globl C$$IO$$\nnop\nC$$IO$$:nop" : "+m" (_CIOBUF_));
 232 }
 233
 234 static inline void
 235 semi_call_wrapper (unsigned char command, const char *data,
 236                    unsigned int length)
 237 {
 238   _CIOBUF_.u.to_host.length = length;
 239   _CIOBUF_.u.to_host.command = command;
 240   if (data != NULL)
 241     memcpy (_CIOBUF_.u.to_host.data, data, length);
 242   do_semi_call ();
 243 }
 244
 245 static inline void
 246 semi_call_wrapper2 (unsigned char command, const char *data1,
 247                     unsigned int length1, const char *data2,
 248                     unsigned int length2)
 249 {
 250   _CIOBUF_.u.to_host.length = length1 + length2;
 251   _CIOBUF_.u.to_host.command = command;
 252   if (data1 != NULL)
 253     memcpy (_CIOBUF_.u.to_host.data, data1, length1);
 254   if (data2 != NULL)
 255     memcpy (_CIOBUF_.u.to_host.data + length1, data2, length2);
 256   do_semi_call ();
 257 }
 258
 259 void
 260 _exit (int status)
 261 {
 262   /* The semihosting interface appears to provide no way to return an
 263      exit status.  */
 264   asm volatile (".globl C$$EXIT\nnop\nC$$EXIT:nop");
 265 }
 266
 267 int
 268 open (const char *path, int flags, ...)
 269 {
 270   /* ??? It's not clear what the suggested fd is for.  */
 271   static short suggest_fd = 3;
 272   short ret_fd;
 273   ++suggest_fd;
 274   _CIOBUF_.u.to_host.parms.open.fd = SWAPSHORT (suggest_fd);
 275   _CIOBUF_.u.to_host.parms.open.flags = SWAPSHORT (flags);
 276   semi_call_wrapper (_DTOPEN, path, strlen (path) + 1);
 277   ret_fd = SWAPSHORT (_CIOBUF_.u.from_host.parms.open.fd);
 278   if (ret_fd == -1)
 279     return -1;
 280   return suggest_fd;
 281 }
 282
 283 int
 284 close (int fd)
 285 {
 286   _CIOBUF_.u.to_host.parms.close.fd = SWAPSHORT (fd);
 287   semi_call_wrapper (_DTCLOSE, NULL, 0);
 288   return SWAPSHORT (_CIOBUF_.u.from_host.parms.close.result);
 289 }
 290
 291 int
 292 read (int fd, char *ptr, int len)
 293 {
 294   if (len > BUFSIZ)
 295     len = BUFSIZ;
 296   _CIOBUF_.u.to_host.parms.read.fd = SWAPSHORT (fd);
 297   _CIOBUF_.u.to_host.parms.read.length = SWAPSHORT (len);
 298   semi_call_wrapper (_DTREAD, NULL, 0);
 299   memcpy (ptr, _CIOBUF_.u.from_host.data, _CIOBUF_.u.from_host.length);
 300   return SWAPSHORT (_CIOBUF_.u.from_host.parms.read.result);
 301 }
 302
 303 int
 304 write (int fd, char *ptr, int len)
 305 {
 306   if (len > BUFSIZ)
 307     len = BUFSIZ;
 308   _CIOBUF_.u.to_host.parms.write.fd = SWAPSHORT (fd);
 309   _CIOBUF_.u.to_host.parms.write.length = SWAPSHORT (len);
 310   semi_call_wrapper (_DTWRITE, ptr, len);
 311   return SWAPSHORT (_CIOBUF_.u.from_host.parms.write.result);
 312 }
 313
 314 int
 315 lseek (int fd, int offset, int whence)
 316 {
 317   _CIOBUF_.u.to_host.parms.lseek.fd = SWAPSHORT (fd);
 318   _CIOBUF_.u.to_host.parms.lseek.offset = SWAPINT (offset);
 319   _CIOBUF_.u.to_host.parms.lseek.whence = SWAPSHORT (whence);
 320   semi_call_wrapper (_DTLSEEK, NULL, 0);
 321   return SWAPINT (_CIOBUF_.u.from_host.parms.lseek.result);
 322 }
 323
 324 int
 325 unlink (const char *path)
 326 {
 327   semi_call_wrapper (_DTUNLINK, path, strlen (path) + 1);
 328   return SWAPSHORT (_CIOBUF_.u.from_host.parms.unlink.result);
 329 }
 330
 331 int
 332 rename (const char *oldpath, const char *newpath)
 333 {
 334   semi_call_wrapper2 (_DTRENAME, oldpath, strlen (oldpath) + 1,
 335                       newpath, strlen (newpath) + 1);
 336   return SWAPSHORT (_CIOBUF_.u.from_host.parms.rename.result);
 337 }
 338
 339 int
 340 gettimeofday (struct timeval *tp, void *tzvp)
 341 {
 342   struct timezone *tzp = tzvp;
 343
 344   if (tp)
 345     {
 346       semi_call_wrapper (_DTGETTIME, NULL, 0);
 347       tp->tv_sec = SWAPINT (_CIOBUF_.u.from_host.parms.gettime.time);
 348       tp->tv_usec = 0;
 349     }
 350
 351   if (tzp)
 352     {
 353       tzp->tz_minuteswest = 0;
 354       tzp->tz_dsttime = 0;
 355     }
 356
 357   return 0;
 358 }
 359
 360 clock_t
 361 clock (void)
 362 {
 363   semi_call_wrapper (_DTGETCLK, NULL, 0);
 364   return SWAPINT (_CIOBUF_.u.from_host.parms.getclk.result);
 365 }
 366
 367
 368 int
 369 isatty (int file __attribute__((unused)))
 370 {
 371   errno = ENOSYS;
 372   return 0;
 373 }
 374
 375 int
 376 fstat (int fd, struct stat *buf)
 377 {
 378   buf->st_mode = S_IFCHR;       /* Always pretend to be a tty */
 379   buf->st_blksize = 0;
 380
 381   return (0);
 382 }