target-arm/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 "exec/gdbstub.h"
  37 #include "hw/arm/arm.h"
  38 #endif
  39
  40 #define TARGET_SYS_OPEN        0x01
  41 #define TARGET_SYS_CLOSE       0x02
  42 #define TARGET_SYS_WRITEC      0x03
  43 #define TARGET_SYS_WRITE0      0x04
  44 #define TARGET_SYS_WRITE       0x05
  45 #define TARGET_SYS_READ        0x06
  46 #define TARGET_SYS_READC       0x07
  47 #define TARGET_SYS_ISTTY       0x09
  48 #define TARGET_SYS_SEEK        0x0a
  49 #define TARGET_SYS_FLEN        0x0c
  50 #define TARGET_SYS_TMPNAM      0x0d
  51 #define TARGET_SYS_REMOVE      0x0e
  52 #define TARGET_SYS_RENAME      0x0f
  53 #define TARGET_SYS_CLOCK       0x10
  54 #define TARGET_SYS_TIME        0x11
  55 #define TARGET_SYS_SYSTEM      0x12
  56 #define TARGET_SYS_ERRNO       0x13
  57 #define TARGET_SYS_GET_CMDLINE 0x15
  58 #define TARGET_SYS_HEAPINFO    0x16
  59 #define TARGET_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(CPUARMState *env, uint32_t code)
 112 {
 113     return code;
 114 }
 115
 116 #include "exec/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(CPUARMState *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 TARGET_SYS_WRITE:
 142         case TARGET_SYS_READ:
 143             env->regs[0] = arm_semi_syscall_len - ret;
 144             break;
 145         case TARGET_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(CPUARMState *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 /* Read the input value from the argument block; fail the semihosting
 170  * call if the memory read fails.
 171  */
 172 #define GET_ARG(n) do {                                 \
 173     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 174         return (uint32_t)-1;                            \
 175     }                                                   \
 176 } while (0)
 177
 178 #define SET_ARG(n, val) put_user_ual(val, args + (n) * 4)
 179 uint32_t do_arm_semihosting(CPUARMState *env)
 180 {
 181     target_ulong args;
 182     target_ulong arg0, arg1, arg2, arg3;
 183     char * s;
 184     int nr;
 185     uint32_t ret;
 186     uint32_t len;
 187 #ifdef CONFIG_USER_ONLY
 188     TaskState *ts = env->opaque;
 189 #else
 190     CPUARMState *ts = env;
 191 #endif
 192
 193     nr = env->regs[0];
 194     args = env->regs[1];
 195     switch (nr) {
 196     case TARGET_SYS_OPEN:
 197         GET_ARG(0);
 198         GET_ARG(1);
 199         GET_ARG(2);
 200         s = lock_user_string(arg0);
 201         if (!s) {
 202             /* FIXME - should this error code be -TARGET_EFAULT ? */
 203             return (uint32_t)-1;
 204         }
 205         if (arg1 >= 12) {
 206             unlock_user(s, arg0, 0);
 207             return (uint32_t)-1;
 208         }
 209         if (strcmp(s, ":tt") == 0) {
 210             int result_fileno = arg1 < 4 ? STDIN_FILENO : STDOUT_FILENO;
 211             unlock_user(s, arg0, 0);
 212             return result_fileno;
 213         }
 214         if (use_gdb_syscalls()) {
 215             gdb_do_syscall(arm_semi_cb, "open,%s,%x,1a4", arg0,
 216                            (int)arg2+1, gdb_open_modeflags[arg1]);
 217             ret = env->regs[0];
 218         } else {
 219             ret = set_swi_errno(ts, open(s, open_modeflags[arg1], 0644));
 220         }
 221         unlock_user(s, arg0, 0);
 222         return ret;
 223     case TARGET_SYS_CLOSE:
 224         GET_ARG(0);
 225         if (use_gdb_syscalls()) {
 226             gdb_do_syscall(arm_semi_cb, "close,%x", arg0);
 227             return env->regs[0];
 228         } else {
 229             return set_swi_errno(ts, close(arg0));
 230         }
 231     case TARGET_SYS_WRITEC:
 232         {
 233           char c;
 234
 235           if (get_user_u8(c, args))
 236               /* FIXME - should this error code be -TARGET_EFAULT ? */
 237               return (uint32_t)-1;
 238           /* Write to debug console.  stderr is near enough.  */
 239           if (use_gdb_syscalls()) {
 240                 gdb_do_syscall(arm_semi_cb, "write,2,%x,1", args);
 241                 return env->regs[0];
 242           } else {
 243                 return write(STDERR_FILENO, &c, 1);
 244           }
 245         }
 246     case TARGET_SYS_WRITE0:
 247         if (!(s = lock_user_string(args)))
 248             /* FIXME - should this error code be -TARGET_EFAULT ? */
 249             return (uint32_t)-1;
 250         len = strlen(s);
 251         if (use_gdb_syscalls()) {
 252             gdb_do_syscall(arm_semi_cb, "write,2,%x,%x\n", args, len);
 253             ret = env->regs[0];
 254         } else {
 255             ret = write(STDERR_FILENO, s, len);
 256         }
 257         unlock_user(s, args, 0);
 258         return ret;
 259     case TARGET_SYS_WRITE:
 260         GET_ARG(0);
 261         GET_ARG(1);
 262         GET_ARG(2);
 263         len = arg2;
 264         if (use_gdb_syscalls()) {
 265             arm_semi_syscall_len = len;
 266             gdb_do_syscall(arm_semi_cb, "write,%x,%x,%x", arg0, arg1, len);
 267             return env->regs[0];
 268         } else {
 269             s = lock_user(VERIFY_READ, arg1, len, 1);
 270             if (!s) {
 271                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 272                 return (uint32_t)-1;
 273             }
 274             ret = set_swi_errno(ts, write(arg0, s, len));
 275             unlock_user(s, arg1, 0);
 276             if (ret == (uint32_t)-1)
 277                 return -1;
 278             return len - ret;
 279         }
 280     case TARGET_SYS_READ:
 281         GET_ARG(0);
 282         GET_ARG(1);
 283         GET_ARG(2);
 284         len = arg2;
 285         if (use_gdb_syscalls()) {
 286             arm_semi_syscall_len = len;
 287             gdb_do_syscall(arm_semi_cb, "read,%x,%x,%x", arg0, arg1, len);
 288             return env->regs[0];
 289         } else {
 290             s = lock_user(VERIFY_WRITE, arg1, len, 0);
 291             if (!s) {
 292                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 293                 return (uint32_t)-1;
 294             }
 295             do {
 296                 ret = set_swi_errno(ts, read(arg0, s, len));
 297             } while (ret == -1 && errno == EINTR);
 298             unlock_user(s, arg1, len);
 299             if (ret == (uint32_t)-1)
 300                 return -1;
 301             return len - ret;
 302         }
 303     case TARGET_SYS_READC:
 304        /* XXX: Read from debug console. Not implemented.  */
 305         return 0;
 306     case TARGET_SYS_ISTTY:
 307         GET_ARG(0);
 308         if (use_gdb_syscalls()) {
 309             gdb_do_syscall(arm_semi_cb, "isatty,%x", arg0);
 310             return env->regs[0];
 311         } else {
 312             return isatty(arg0);
 313         }
 314     case TARGET_SYS_SEEK:
 315         GET_ARG(0);
 316         GET_ARG(1);
 317         if (use_gdb_syscalls()) {
 318             gdb_do_syscall(arm_semi_cb, "lseek,%x,%x,0", arg0, arg1);
 319             return env->regs[0];
 320         } else {
 321             ret = set_swi_errno(ts, lseek(arg0, arg1, SEEK_SET));
 322             if (ret == (uint32_t)-1)
 323               return -1;
 324             return 0;
 325         }
 326     case TARGET_SYS_FLEN:
 327         GET_ARG(0);
 328         if (use_gdb_syscalls()) {
 329             gdb_do_syscall(arm_semi_flen_cb, "fstat,%x,%x",
 330                            arg0, env->regs[13]-64);
 331             return env->regs[0];
 332         } else {
 333             struct stat buf;
 334             ret = set_swi_errno(ts, fstat(arg0, &buf));
 335             if (ret == (uint32_t)-1)
 336                 return -1;
 337             return buf.st_size;
 338         }
 339     case TARGET_SYS_TMPNAM:
 340         /* XXX: Not implemented.  */
 341         return -1;
 342     case TARGET_SYS_REMOVE:
 343         GET_ARG(0);
 344         GET_ARG(1);
 345         if (use_gdb_syscalls()) {
 346             gdb_do_syscall(arm_semi_cb, "unlink,%s", arg0, (int)arg1+1);
 347             ret = env->regs[0];
 348         } else {
 349             s = lock_user_string(arg0);
 350             if (!s) {
 351                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 352                 return (uint32_t)-1;
 353             }
 354             ret =  set_swi_errno(ts, remove(s));
 355             unlock_user(s, arg0, 0);
 356         }
 357         return ret;
 358     case TARGET_SYS_RENAME:
 359         GET_ARG(0);
 360         GET_ARG(1);
 361         GET_ARG(2);
 362         GET_ARG(3);
 363         if (use_gdb_syscalls()) {
 364             gdb_do_syscall(arm_semi_cb, "rename,%s,%s",
 365                            arg0, (int)arg1+1, arg2, (int)arg3+1);
 366             return env->regs[0];
 367         } else {
 368             char *s2;
 369             s = lock_user_string(arg0);
 370             s2 = lock_user_string(arg2);
 371             if (!s || !s2)
 372                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 373                 ret = (uint32_t)-1;
 374             else
 375                 ret = set_swi_errno(ts, rename(s, s2));
 376             if (s2)
 377                 unlock_user(s2, arg2, 0);
 378             if (s)
 379                 unlock_user(s, arg0, 0);
 380             return ret;
 381         }
 382     case TARGET_SYS_CLOCK:
 383         return clock() / (CLOCKS_PER_SEC / 100);
 384     case TARGET_SYS_TIME:
 385         return set_swi_errno(ts, time(NULL));
 386     case TARGET_SYS_SYSTEM:
 387         GET_ARG(0);
 388         GET_ARG(1);
 389         if (use_gdb_syscalls()) {
 390             gdb_do_syscall(arm_semi_cb, "system,%s", arg0, (int)arg1+1);
 391             return env->regs[0];
 392         } else {
 393             s = lock_user_string(arg0);
 394             if (!s) {
 395                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 396                 return (uint32_t)-1;
 397             }
 398             ret = set_swi_errno(ts, system(s));
 399             unlock_user(s, arg0, 0);
 400             return ret;
 401         }
 402     case TARGET_SYS_ERRNO:
 403 #ifdef CONFIG_USER_ONLY
 404         return ts->swi_errno;
 405 #else
 406         return syscall_err;
 407 #endif
 408     case TARGET_SYS_GET_CMDLINE:
 409         {
 410             /* Build a command-line from the original argv.
 411              *
 412              * The inputs are:
 413              *     * arg0, pointer to a buffer of at least the size
 414              *               specified in arg1.
 415              *     * arg1, size of the buffer pointed to by arg0 in
 416              *               bytes.
 417              *
 418              * The outputs are:
 419              *     * arg0, pointer to null-terminated string of the
 420              *               command line.
 421              *     * arg1, length of the string pointed to by arg0.
 422              */
 423
 424             char *output_buffer;
 425             size_t input_size;
 426             size_t output_size;
 427             int status = 0;
 428             GET_ARG(0);
 429             GET_ARG(1);
 430             input_size = arg1;
 431             /* Compute the size of the output string.  */
 432 #if !defined(CONFIG_USER_ONLY)
 433             output_size = strlen(ts->boot_info->kernel_filename)
 434                         + 1  /* Separating space.  */
 435                         + strlen(ts->boot_info->kernel_cmdline)
 436                         + 1; /* Terminating null byte.  */
 437 #else
 438             unsigned int i;
 439
 440             output_size = ts->info->arg_end - ts->info->arg_start;
 441             if (!output_size) {
 442                 /* We special-case the "empty command line" case (argc==0).
 443                    Just provide the terminating 0. */
 444                 output_size = 1;
 445             }
 446 #endif
 447
 448             if (output_size > input_size) {
 449                  /* Not enough space to store command-line arguments.  */
 450                 return -1;
 451             }
 452
 453             /* Adjust the command-line length.  */
 454             if (SET_ARG(1, output_size - 1)) {
 455                 /* Couldn't write back to argument block */
 456                 return -1;
 457             }
 458
 459             /* Lock the buffer on the ARM side.  */
 460             output_buffer = lock_user(VERIFY_WRITE, arg0, output_size, 0);
 461             if (!output_buffer) {
 462                 return -1;
 463             }
 464
 465             /* Copy the command-line arguments.  */
 466 #if !defined(CONFIG_USER_ONLY)
 467             pstrcpy(output_buffer, output_size, ts->boot_info->kernel_filename);
 468             pstrcat(output_buffer, output_size, " ");
 469             pstrcat(output_buffer, output_size, ts->boot_info->kernel_cmdline);
 470 #else
 471             if (output_size == 1) {
 472                 /* Empty command-line.  */
 473                 output_buffer[0] = '\0';
 474                 goto out;
 475             }
 476
 477             if (copy_from_user(output_buffer, ts->info->arg_start,
 478                                output_size)) {
 479                 status = -1;
 480                 goto out;
 481             }
 482
 483             /* Separate arguments by white spaces.  */
 484             for (i = 0; i < output_size - 1; i++) {
 485                 if (output_buffer[i] == 0) {
 486                     output_buffer[i] = ' ';
 487                 }
 488             }
 489         out:
 490 #endif
 491             /* Unlock the buffer on the ARM side.  */
 492             unlock_user(output_buffer, arg0, output_size);
 493
 494             return status;
 495         }
 496     case TARGET_SYS_HEAPINFO:
 497         {
 498             uint32_t *ptr;
 499             uint32_t limit;
 500             GET_ARG(0);
 501
 502 #ifdef CONFIG_USER_ONLY
 503             /* Some C libraries assume the heap immediately follows .bss, so
 504                allocate it using sbrk.  */
 505             if (!ts->heap_limit) {
 506                 abi_ulong ret;
 507
 508                 ts->heap_base = do_brk(0);
 509                 limit = ts->heap_base + ARM_ANGEL_HEAP_SIZE;
 510                 /* Try a big heap, and reduce the size if that fails.  */
 511                 for (;;) {
 512                     ret = do_brk(limit);
 513                     if (ret >= limit) {
 514                         break;
 515                     }
 516                     limit = (ts->heap_base >> 1) + (limit >> 1);
 517                 }
 518                 ts->heap_limit = limit;
 519             }
 520
 521             ptr = lock_user(VERIFY_WRITE, arg0, 16, 0);
 522             if (!ptr) {
 523                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 524                 return (uint32_t)-1;
 525             }
 526             ptr[0] = tswap32(ts->heap_base);
 527             ptr[1] = tswap32(ts->heap_limit);
 528             ptr[2] = tswap32(ts->stack_base);
 529             ptr[3] = tswap32(0); /* Stack limit.  */
 530             unlock_user(ptr, arg0, 16);
 531 #else
 532             limit = ram_size;
 533             ptr = lock_user(VERIFY_WRITE, arg0, 16, 0);
 534             if (!ptr) {
 535                 /* FIXME - should this error code be -TARGET_EFAULT ? */
 536                 return (uint32_t)-1;
 537             }
 538             /* TODO: Make this use the limit of the loaded application.  */
 539             ptr[0] = tswap32(limit / 2);
 540             ptr[1] = tswap32(limit);
 541             ptr[2] = tswap32(limit); /* Stack base */
 542             ptr[3] = tswap32(0); /* Stack limit.  */
 543             unlock_user(ptr, arg0, 16);
 544 #endif
 545             return 0;
 546         }
 547     case TARGET_SYS_EXIT:
 548         gdb_exit(env, 0);
 549         exit(0);
 550     default:
 551         fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
 552         cpu_dump_state(env, stderr, fprintf, 0);
 553         abort();
 554     }
 555 }