arm-semi.c

   1 /*
   2  *  Arm "Angel" semihosting syscalls
   3  *
   4  *  Copyright (c) 2005, 2007 CodeSourcery.
   5  *  Written by Paul Brook.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <time.h>
  28
  29 #include "cpu.h"
  30 #ifdef CONFIG_USER_ONLY
  31 #include "qemu.h"
  32
  33 #define ARM_ANGEL_HEAP_SIZE (128 * 1024 * 1024)
  34 #else
  35 #include "qemu-common.h"
  36 #include "gdbstub.h"
  37 #include "hw/arm-misc.h"
  38 #endif
  39
  40 #define SYS_OPEN        0x01
  41 #define SYS_CLOSE       0x02
  42 #define SYS_WRITEC      0x03
  43 #define SYS_WRITE0      0x04
  44 #define SYS_WRITE       0x05
  45 #define SYS_READ        0x06
  46 #define SYS_READC       0x07
  47 #define SYS_ISTTY       0x09
  48 #define SYS_SEEK        0x0a
  49 #define SYS_FLEN        0x0c
  50 #define SYS_TMPNAM      0x0d
  51 #define SYS_REMOVE      0x0e
  52 #define SYS_RENAME      0x0f
  53 #define SYS_CLOCK       0x10
  54 #define SYS_TIME        0x11
  55 #define SYS_SYSTEM      0x12
  56 #define SYS_ERRNO       0x13
  57 #define SYS_GET_CMDLINE 0x15
  58 #define SYS_HEAPINFO    0x16
  59 #define SYS_EXIT        0x18
  60
  61 #ifndef O_BINARY
  62 #define O_BINARY 0
  63 #endif
  64
  65 #define GDB_O_RDONLY  0x000
  66 #define GDB_O_WRONLY  0x001
  67 #define GDB_O_RDWR    0x002
  68 #define GDB_O_APPEND  0x008
  69 #define GDB_O_CREAT   0x200
  70 #define GDB_O_TRUNC   0x400
  71 #define GDB_O_BINARY  0
  72
  73 static int gdb_open_modeflags[12] = {
  74     GDB_O_RDONLY,
  75     GDB_O_RDONLY | GDB_O_BINARY,
  76     GDB_O_RDWR,
  77     GDB_O_RDWR | GDB_O_BINARY,
  78     GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC,
  79     GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,
  80     GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC,
  81     GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,
  82     GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND,
  83     GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY,
  84     GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND,
  85     GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY
  86 };
  87
  88 static int open_modeflags[12] = {
  89     O_RDONLY,
  90     O_RDONLY | O_BINARY,
  91     O_RDWR,
  92     O_RDWR | O_BINARY,
  93     O_WRONLY | O_CREAT | O_TRUNC,
  94     O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
  95     O_RDWR | O_CREAT | O_TRUNC,
  96     O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
  97     O_WRONLY | O_CREAT | O_APPEND,
  98     O_WRONLY | O_CREAT | O_APPEND | O_BINARY,
  99     O_RDWR | O_CREAT | O_APPEND,
 100     O_RDWR | O_CREAT | O_APPEND | O_BINARY
 101 };
 102
 103 #ifdef CONFIG_USER_ONLY
 104 static inline uint32_t set_swi_errno(TaskState *ts, uint32_t code)
 105 {
 106     if (code == (uint32_t)-1)
 107         ts->swi_errno = errno;
 108     return code;
 109 }
 110 #else
 111 static inline uint32_t set_swi_errno(CPUState *env, uint32_t code)
 112 {
 113     return code;
 114 }
 115
 116 #include "softmmu-semi.h"
 117 #endif
 118
 119 static target_ulong arm_semi_syscall_len;
 120
 121 #if !defined(CONFIG_USER_ONLY)
 122 static target_ulong syscall_err;
 123 #endif
 124
 125 static void arm_semi_cb(CPUState *env, target_ulong ret, target_ulong err)
 126 {
 127 #ifdef CONFIG_USER_ONLY
 128     TaskState *ts = env->opaque;
 129 #endif
 130
 131     if (ret == (target_ulong)-1) {
 132 #ifdef CONFIG_USER_ONLY
 133         ts->swi_errno = err;
 134 #else
 135         syscall_err = err;
 136 #endif
 137         env->regs[0] = ret;
 138     } else {
 139         /* Fixup syscalls that use nonstardard return conventions.  */
 140         switch (env->regs[0]) {
 141         case SYS_WRITE:
 142         case SYS_READ:
 143             env->regs[0] = arm_semi_syscall_len - ret;
 144             break;
 145         case SYS_SEEK:
 146             env->regs[0] = 0;
 147             break;
 148         default:
 149             env->regs[0] = ret;
 150             break;
 151         }
 152     }
 153 }
 154
 155 static void arm_semi_flen_cb(CPUState *env, target_ulong ret, target_ulong err)
 156 {
 157     /* The size is always stored in big-endian order, extract
 158        the value. We assume the size always fit in 32 bits.  */
 159     uint32_t size;
 160     cpu_memory_rw_debug(env, env->regs[13]-64+32, (uint8_t *)&size, 4, 0);
 161     env->regs[0] = be32_to_cpu(size);
 162 #ifdef CONFIG_USER_ONLY
 163     ((TaskState *)env->opaque)->swi_errno = err;
 164 #else
 165     syscall_err = err;
 166 #endif
 167 }
 168
 169 #define ARG(n)                                  \
 170 ({                                              \
 171     target_ulong __arg;                         \
 172     /* FIXME - handle get_user() failure */     \
 173     get_user_ual(__arg, args + (n) * 4);        \
 174     __arg;                                      \
 175 })
 176 #define SET_ARG(n, val) put_user_ual(val, args + (n) * 4)
 177 uint32_t do_arm_semihosting(CPUState *env)
 178 {
 179     target_ulong args;
 180     char * s;
 181     int nr;
 182     uint32_t ret;
 183     uint32_t len;
 184 #ifdef CONFIG_USER_ONLY
 185     TaskState *ts = env->opaque;
 186 #else
 187     CPUState *ts = env;
 188 #endif
 189
 190     nr = env->regs[0];
 191     args = env->regs[1];
 192     switch (nr) {
 193     case SYS_OPEN:
 194         if (!(s = lock_user_string(ARG(0))))
 195             /* FIXME - should this error code be -TARGET_EFAULT ? */
 196             return (uint32_t)-1;
 197         if (ARG(1) >= 12)
 198             return (uint32_t)-1;
 199         if (strcmp(s, ":tt") == 0) {
 200             if (ARG(1) < 4)
 201                 return STDIN_FILENO;
 202             else
 203                 return STDOUT_FILENO;
 204         }
 205         if (use_gdb_syscalls()) {
 206             gdb_do_syscall(arm_semi_cb, "open,%s,%x,1a4", ARG(0),
 207                            (int)ARG(2)+1, gdb_open_modeflags[ARG(1)]);
 208             return env->regs[0];
 209         } else {
 210             ret = set_swi_errno(ts, open(s, open_modeflags[ARG(1)], 0644));
 211         }
 212         unlock_user(s, ARG(0), 0);
 213         return ret;
 214     case SYS_CLOSE:
 215         if (use_gdb_syscalls()) {
 216             gdb_do_syscall(arm_semi_cb, "close,%x", ARG(0));
 217             return env->regs[0];
 218         } else {
 219             return set_swi_errno(ts, close(ARG(0)));
 220         }
 221     case SYS_WRITEC:
 222         {
 223           char c;
 224
 225           if (get_user_u8(c, args))
 226               /* FIXME - should this error code be -TARGET_EFAULT ? */
 227               return (uint32_t)-1;
 228           /* Write to debug console.  stderr is near enough.  */
 229           if (use_gdb_syscalls()) {
 230                 gdb_do_syscall(arm_semi_cb, "write,2,%x,1", args);
 231                 return env->regs[0];
 232           } else {
 233                 return write(STDERR_FILENO, &c, 1);
 234           }
 235         }
 236     case SYS_WRITE0:
 237         if (!(s = lock_user_string(args)))
 238             /* FIXME - should this error code be -TARGET_EFAULT ? */
 239             return (uint32_t)-1;
 240         len = strlen(s);
 241         if (use_gdb_syscalls()) {
 242             gdb_do_syscall(arm_semi_cb, "write,2,%x,%x\n", args, len);
 243             ret = env->regs[0];
 244         } else {
 245             ret = write(STDERR_FILENO, s, len);
 246         }
 247         unlock_user(s, args, 0);
 248         return ret;
 249     case SYS_WRITE:
 250         len = ARG(2);
 251         if (use_gdb_syscalls()) {
 252             arm_semi_syscall_len = len;
 253             gdb_do_syscall(arm_semi_cb, "write,%x,%x,%x", ARG(0), ARG(1), len);
 254             return env->regs[0];
 255         } else {
 256             if (!(s = lock_user(VERIFY_READ, ARG(1), len, 1)))
 257                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 258                 return (uint32_t)-1;
 259             ret = set_swi_errno(ts, write(ARG(0), s, len));
 260             unlock_user(s, ARG(1), 0);
 261             if (ret == (uint32_t)-1)
 262                 return -1;
 263             return len - ret;
 264         }
 265     case SYS_READ:
 266         len = ARG(2);
 267         if (use_gdb_syscalls()) {
 268             arm_semi_syscall_len = len;
 269             gdb_do_syscall(arm_semi_cb, "read,%x,%x,%x", ARG(0), ARG(1), len);
 270             return env->regs[0];
 271         } else {
 272             if (!(s = lock_user(VERIFY_WRITE, ARG(1), len, 0)))
 273                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 274                 return (uint32_t)-1;
 275             do
 276               ret = set_swi_errno(ts, read(ARG(0), s, len));
 277             while (ret == -1 && errno == EINTR);
 278             unlock_user(s, ARG(1), len);
 279             if (ret == (uint32_t)-1)
 280                 return -1;
 281             return len - ret;
 282         }
 283     case SYS_READC:
 284        /* XXX: Read from debug cosole. Not implemented.  */
 285         return 0;
 286     case SYS_ISTTY:
 287         if (use_gdb_syscalls()) {
 288             gdb_do_syscall(arm_semi_cb, "isatty,%x", ARG(0));
 289             return env->regs[0];
 290         } else {
 291             return isatty(ARG(0));
 292         }
 293     case SYS_SEEK:
 294         if (use_gdb_syscalls()) {
 295             gdb_do_syscall(arm_semi_cb, "lseek,%x,%x,0", ARG(0), ARG(1));
 296             return env->regs[0];
 297         } else {
 298             ret = set_swi_errno(ts, lseek(ARG(0), ARG(1), SEEK_SET));
 299             if (ret == (uint32_t)-1)
 300               return -1;
 301             return 0;
 302         }
 303     case SYS_FLEN:
 304         if (use_gdb_syscalls()) {
 305             gdb_do_syscall(arm_semi_flen_cb, "fstat,%x,%x",
 306                            ARG(0), env->regs[13]-64);
 307             return env->regs[0];
 308         } else {
 309             struct stat buf;
 310             ret = set_swi_errno(ts, fstat(ARG(0), &buf));
 311             if (ret == (uint32_t)-1)
 312                 return -1;
 313             return buf.st_size;
 314         }
 315     case SYS_TMPNAM:
 316         /* XXX: Not implemented.  */
 317         return -1;
 318     case SYS_REMOVE:
 319         if (use_gdb_syscalls()) {
 320             gdb_do_syscall(arm_semi_cb, "unlink,%s", ARG(0), (int)ARG(1)+1);
 321             ret = env->regs[0];
 322         } else {
 323             if (!(s = lock_user_string(ARG(0))))
 324                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 325                 return (uint32_t)-1;
 326             ret =  set_swi_errno(ts, remove(s));
 327             unlock_user(s, ARG(0), 0);
 328         }
 329         return ret;
 330     case SYS_RENAME:
 331         if (use_gdb_syscalls()) {
 332             gdb_do_syscall(arm_semi_cb, "rename,%s,%s",
 333                            ARG(0), (int)ARG(1)+1, ARG(2), (int)ARG(3)+1);
 334             return env->regs[0];
 335         } else {
 336             char *s2;
 337             s = lock_user_string(ARG(0));
 338             s2 = lock_user_string(ARG(2));
 339             if (!s || !s2)
 340                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 341                 ret = (uint32_t)-1;
 342             else
 343                 ret = set_swi_errno(ts, rename(s, s2));
 344             if (s2)
 345                 unlock_user(s2, ARG(2), 0);
 346             if (s)
 347                 unlock_user(s, ARG(0), 0);
 348             return ret;
 349         }
 350     case SYS_CLOCK:
 351         return clock() / (CLOCKS_PER_SEC / 100);
 352     case SYS_TIME:
 353         return set_swi_errno(ts, time(NULL));
 354     case SYS_SYSTEM:
 355         if (use_gdb_syscalls()) {
 356             gdb_do_syscall(arm_semi_cb, "system,%s", ARG(0), (int)ARG(1)+1);
 357             return env->regs[0];
 358         } else {
 359             if (!(s = lock_user_string(ARG(0))))
 360                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 361                 return (uint32_t)-1;
 362             ret = set_swi_errno(ts, system(s));
 363             unlock_user(s, ARG(0), 0);
 364             return ret;
 365         }
 366     case SYS_ERRNO:
 367 #ifdef CONFIG_USER_ONLY
 368         return ts->swi_errno;
 369 #else
 370         return syscall_err;
 371 #endif
 372     case SYS_GET_CMDLINE:
 373         {
 374             /* Build a command-line from the original argv.
 375              *
 376              * The inputs are:
 377              *     * ARG(0), pointer to a buffer of at least the size
 378              *               specified in ARG(1).
 379              *     * ARG(1), size of the buffer pointed to by ARG(0) in
 380              *               bytes.
 381              *
 382              * The outputs are:
 383              *     * ARG(0), pointer to null-terminated string of the
 384              *               command line.
 385              *     * ARG(1), length of the string pointed to by ARG(0).
 386              */
 387
 388             char *output_buffer;
 389             size_t input_size = ARG(1);
 390             size_t output_size;
 391             int status = 0;
 392
 393             /* Compute the size of the output string.  */
 394 #if !defined(CONFIG_USER_ONLY)
 395             output_size = strlen(ts->boot_info->kernel_filename)
 396                         + 1  /* Separating space.  */
 397                         + strlen(ts->boot_info->kernel_cmdline)
 398                         + 1; /* Terminating null byte.  */
 399 #else
 400             unsigned int i;
 401
 402             output_size = ts->info->arg_end - ts->info->arg_start;
 403             if (!output_size) {
 404                 /* We special-case the "empty command line" case (argc==0).
 405                    Just provide the terminating 0. */
 406                 output_size = 1;
 407             }
 408 #endif
 409
 410             if (output_size > input_size) {
 411                  /* Not enough space to store command-line arguments.  */
 412                 return -1;
 413             }
 414
 415             /* Adjust the command-line length.  */
 416             SET_ARG(1, output_size - 1);
 417
 418             /* Lock the buffer on the ARM side.  */
 419             output_buffer = lock_user(VERIFY_WRITE, ARG(0), output_size, 0);
 420             if (!output_buffer) {
 421                 return -1;
 422             }
 423
 424             /* Copy the command-line arguments.  */
 425 #if !defined(CONFIG_USER_ONLY)
 426             pstrcpy(output_buffer, output_size, ts->boot_info->kernel_filename);
 427             pstrcat(output_buffer, output_size, " ");
 428             pstrcat(output_buffer, output_size, ts->boot_info->kernel_cmdline);
 429 #else
 430             if (output_size == 1) {
 431                 /* Empty command-line.  */
 432                 output_buffer[0] = '\0';
 433                 goto out;
 434             }
 435
 436             if (copy_from_user(output_buffer, ts->info->arg_start,
 437                                output_size)) {
 438                 status = -1;
 439                 goto out;
 440             }
 441
 442             /* Separate arguments by white spaces.  */
 443             for (i = 0; i < output_size - 1; i++) {
 444                 if (output_buffer[i] == 0) {
 445                     output_buffer[i] = ' ';
 446                 }
 447             }
 448         out:
 449 #endif
 450             /* Unlock the buffer on the ARM side.  */
 451             unlock_user(output_buffer, ARG(0), output_size);
 452
 453             return status;
 454         }
 455     case SYS_HEAPINFO:
 456         {
 457             uint32_t *ptr;
 458             uint32_t limit;
 459
 460 #ifdef CONFIG_USER_ONLY
 461             /* Some C libraries assume the heap immediately follows .bss, so
 462                allocate it using sbrk.  */
 463             if (!ts->heap_limit) {
 464                 abi_ulong ret;
 465
 466                 ts->heap_base = do_brk(0);
 467                 limit = ts->heap_base + ARM_ANGEL_HEAP_SIZE;
 468                 /* Try a big heap, and reduce the size if that fails.  */
 469                 for (;;) {
 470                     ret = do_brk(limit);
 471                     if (ret >= limit) {
 472                         break;
 473                     }
 474                     limit = (ts->heap_base >> 1) + (limit >> 1);
 475                 }
 476                 ts->heap_limit = limit;
 477             }
 478
 479             if (!(ptr = lock_user(VERIFY_WRITE, ARG(0), 16, 0)))
 480                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 481                 return (uint32_t)-1;
 482             ptr[0] = tswap32(ts->heap_base);
 483             ptr[1] = tswap32(ts->heap_limit);
 484             ptr[2] = tswap32(ts->stack_base);
 485             ptr[3] = tswap32(0); /* Stack limit.  */
 486             unlock_user(ptr, ARG(0), 16);
 487 #else
 488             limit = ram_size;
 489             if (!(ptr = lock_user(VERIFY_WRITE, ARG(0), 16, 0)))
 490                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 491                 return (uint32_t)-1;
 492             /* TODO: Make this use the limit of the loaded application.  */
 493             ptr[0] = tswap32(limit / 2);
 494             ptr[1] = tswap32(limit);
 495             ptr[2] = tswap32(limit); /* Stack base */
 496             ptr[3] = tswap32(0); /* Stack limit.  */
 497             unlock_user(ptr, ARG(0), 16);
 498 #endif
 499             return 0;
 500         }
 501     case SYS_EXIT:
 502         gdb_exit(env, 0);
 503         exit(0);
 504     default:
 505         fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
 506         cpu_dump_state(env, stderr, fprintf, 0);
 507         abort();
 508     }
 509 }