target/m68k/m68k-semi.c

   1 /*
   2  *  m68k/ColdFire Semihosting syscall interface
   3  *
   4  *  Copyright (c) 2005-2007 CodeSourcery.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21
  22 #include "cpu.h"
  23 #if defined(CONFIG_USER_ONLY)
  24 #include "qemu.h"
  25 #define SEMIHOSTING_HEAP_SIZE (128 * 1024 * 1024)
  26 #else
  27 #include "exec/gdbstub.h"
  28 #include "exec/softmmu-semi.h"
  29 #endif
  30 #include "qemu/log.h"
  31
  32 #define HOSTED_EXIT  0
  33 #define HOSTED_INIT_SIM 1
  34 #define HOSTED_OPEN 2
  35 #define HOSTED_CLOSE 3
  36 #define HOSTED_READ 4
  37 #define HOSTED_WRITE 5
  38 #define HOSTED_LSEEK 6
  39 #define HOSTED_RENAME 7
  40 #define HOSTED_UNLINK 8
  41 #define HOSTED_STAT 9
  42 #define HOSTED_FSTAT 10
  43 #define HOSTED_GETTIMEOFDAY 11
  44 #define HOSTED_ISATTY 12
  45 #define HOSTED_SYSTEM 13
  46
  47 typedef uint32_t gdb_mode_t;
  48 typedef uint32_t gdb_time_t;
  49
  50 struct m68k_gdb_stat {
  51   uint32_t    gdb_st_dev;     /* device */
  52   uint32_t    gdb_st_ino;     /* inode */
  53   gdb_mode_t  gdb_st_mode;    /* protection */
  54   uint32_t    gdb_st_nlink;   /* number of hard links */
  55   uint32_t    gdb_st_uid;     /* user ID of owner */
  56   uint32_t    gdb_st_gid;     /* group ID of owner */
  57   uint32_t    gdb_st_rdev;    /* device type (if inode device) */
  58   uint64_t    gdb_st_size;    /* total size, in bytes */
  59   uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
  60   uint64_t    gdb_st_blocks;  /* number of blocks allocated */
  61   gdb_time_t  gdb_st_atime;   /* time of last access */
  62   gdb_time_t  gdb_st_mtime;   /* time of last modification */
  63   gdb_time_t  gdb_st_ctime;   /* time of last change */
  64 } QEMU_PACKED;
  65
  66 struct gdb_timeval {
  67   gdb_time_t tv_sec;  /* second */
  68   uint64_t tv_usec;   /* microsecond */
  69 } QEMU_PACKED;
  70
  71 #define GDB_O_RDONLY   0x0
  72 #define GDB_O_WRONLY   0x1
  73 #define GDB_O_RDWR     0x2
  74 #define GDB_O_APPEND   0x8
  75 #define GDB_O_CREAT  0x200
  76 #define GDB_O_TRUNC  0x400
  77 #define GDB_O_EXCL   0x800
  78
  79 static int translate_openflags(int flags)
  80 {
  81     int hf;
  82
  83     if (flags & GDB_O_WRONLY)
  84         hf = O_WRONLY;
  85     else if (flags & GDB_O_RDWR)
  86         hf = O_RDWR;
  87     else
  88         hf = O_RDONLY;
  89
  90     if (flags & GDB_O_APPEND) hf |= O_APPEND;
  91     if (flags & GDB_O_CREAT) hf |= O_CREAT;
  92     if (flags & GDB_O_TRUNC) hf |= O_TRUNC;
  93     if (flags & GDB_O_EXCL) hf |= O_EXCL;
  94
  95     return hf;
  96 }
  97
  98 static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
  99 {
 100     struct m68k_gdb_stat *p;
 101
 102     if (!(p = lock_user(VERIFY_WRITE, addr, sizeof(struct m68k_gdb_stat), 0)))
 103         /* FIXME - should this return an error code? */
 104         return;
 105     p->gdb_st_dev = cpu_to_be32(s->st_dev);
 106     p->gdb_st_ino = cpu_to_be32(s->st_ino);
 107     p->gdb_st_mode = cpu_to_be32(s->st_mode);
 108     p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
 109     p->gdb_st_uid = cpu_to_be32(s->st_uid);
 110     p->gdb_st_gid = cpu_to_be32(s->st_gid);
 111     p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
 112     p->gdb_st_size = cpu_to_be64(s->st_size);
 113 #ifdef _WIN32
 114     /* Windows stat is missing some fields.  */
 115     p->gdb_st_blksize = 0;
 116     p->gdb_st_blocks = 0;
 117 #else
 118     p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
 119     p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
 120 #endif
 121     p->gdb_st_atime = cpu_to_be32(s->st_atime);
 122     p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
 123     p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
 124     unlock_user(p, addr, sizeof(struct m68k_gdb_stat));
 125 }
 126
 127 static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err)
 128 {
 129     target_ulong args = env->dregs[1];
 130     if (put_user_u32(ret, args) ||
 131         put_user_u32(err, args + 4)) {
 132         /*
 133          * The m68k semihosting ABI does not provide any way to report this
 134          * error to the guest, so the best we can do is log it in qemu.
 135          * It is always a guest error not to pass us a valid argument block.
 136          */
 137         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 138                       "discarded because argument block not writable\n");
 139     }
 140 }
 141
 142 static void m68k_semi_return_u64(CPUM68KState *env, uint64_t ret, uint32_t err)
 143 {
 144     target_ulong args = env->dregs[1];
 145     if (put_user_u32(ret >> 32, args) ||
 146         put_user_u32(ret, args + 4) ||
 147         put_user_u32(err, args + 8)) {
 148         /* No way to report this via m68k semihosting ABI; just log it */
 149         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 150                       "discarded because argument block not writable\n");
 151     }
 152 }
 153
 154 static int m68k_semi_is_fseek;
 155
 156 static void m68k_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
 157 {
 158     M68kCPU *cpu = M68K_CPU(cs);
 159     CPUM68KState *env = &cpu->env;
 160
 161     if (m68k_semi_is_fseek) {
 162         /*
 163          * FIXME: We've already lost the high bits of the fseek
 164          * return value.
 165          */
 166         m68k_semi_return_u64(env, ret, err);
 167         m68k_semi_is_fseek = 0;
 168     } else {
 169         m68k_semi_return_u32(env, ret, err);
 170     }
 171 }
 172
 173 /*
 174  * Read the input value from the argument block; fail the semihosting
 175  * call if the memory read fails.
 176  */
 177 #define GET_ARG(n) do {                                 \
 178     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 179         result = -1;                                    \
 180         errno = EFAULT;                                 \
 181         goto failed;                                    \
 182     }                                                   \
 183 } while (0)
 184
 185 void do_m68k_semihosting(CPUM68KState *env, int nr)
 186 {
 187     uint32_t args;
 188     target_ulong arg0, arg1, arg2, arg3;
 189     void *p;
 190     void *q;
 191     uint32_t len;
 192     uint32_t result;
 193
 194     args = env->dregs[1];
 195     switch (nr) {
 196     case HOSTED_EXIT:
 197         gdb_exit(env, env->dregs[0]);
 198         exit(env->dregs[0]);
 199     case HOSTED_OPEN:
 200         GET_ARG(0);
 201         GET_ARG(1);
 202         GET_ARG(2);
 203         GET_ARG(3);
 204         if (use_gdb_syscalls()) {
 205             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
 206                            arg2, arg3);
 207             return;
 208         } else {
 209             p = lock_user_string(arg0);
 210             if (!p) {
 211                 /* FIXME - check error code? */
 212                 result = -1;
 213             } else {
 214                 result = open(p, translate_openflags(arg2), arg3);
 215                 unlock_user(p, arg0, 0);
 216             }
 217         }
 218         break;
 219     case HOSTED_CLOSE:
 220         {
 221             /* Ignore attempts to close stdin/out/err.  */
 222             GET_ARG(0);
 223             int fd = arg0;
 224             if (fd > 2) {
 225                 if (use_gdb_syscalls()) {
 226                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
 227                     return;
 228                 } else {
 229                     result = close(fd);
 230                 }
 231             } else {
 232                 result = 0;
 233             }
 234             break;
 235         }
 236     case HOSTED_READ:
 237         GET_ARG(0);
 238         GET_ARG(1);
 239         GET_ARG(2);
 240         len = arg2;
 241         if (use_gdb_syscalls()) {
 242             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
 243                            arg0, arg1, len);
 244             return;
 245         } else {
 246             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 247             if (!p) {
 248                 /* FIXME - check error code? */
 249                 result = -1;
 250             } else {
 251                 result = read(arg0, p, len);
 252                 unlock_user(p, arg1, len);
 253             }
 254         }
 255         break;
 256     case HOSTED_WRITE:
 257         GET_ARG(0);
 258         GET_ARG(1);
 259         GET_ARG(2);
 260         len = arg2;
 261         if (use_gdb_syscalls()) {
 262             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
 263                            arg0, arg1, len);
 264             return;
 265         } else {
 266             p = lock_user(VERIFY_READ, arg1, len, 1);
 267             if (!p) {
 268                 /* FIXME - check error code? */
 269                 result = -1;
 270             } else {
 271                 result = write(arg0, p, len);
 272                 unlock_user(p, arg0, 0);
 273             }
 274         }
 275         break;
 276     case HOSTED_LSEEK:
 277         {
 278             uint64_t off;
 279             GET_ARG(0);
 280             GET_ARG(1);
 281             GET_ARG(2);
 282             GET_ARG(3);
 283             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 284             if (use_gdb_syscalls()) {
 285                 m68k_semi_is_fseek = 1;
 286                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
 287                                arg0, off, arg3);
 288             } else {
 289                 off = lseek(arg0, off, arg3);
 290                 m68k_semi_return_u64(env, off, errno);
 291             }
 292             return;
 293         }
 294     case HOSTED_RENAME:
 295         GET_ARG(0);
 296         GET_ARG(1);
 297         GET_ARG(2);
 298         GET_ARG(3);
 299         if (use_gdb_syscalls()) {
 300             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
 301                            arg0, (int)arg1, arg2, (int)arg3);
 302             return;
 303         } else {
 304             p = lock_user_string(arg0);
 305             q = lock_user_string(arg2);
 306             if (!p || !q) {
 307                 /* FIXME - check error code? */
 308                 result = -1;
 309             } else {
 310                 result = rename(p, q);
 311             }
 312             unlock_user(p, arg0, 0);
 313             unlock_user(q, arg2, 0);
 314         }
 315         break;
 316     case HOSTED_UNLINK:
 317         GET_ARG(0);
 318         GET_ARG(1);
 319         if (use_gdb_syscalls()) {
 320             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
 321                            arg0, (int)arg1);
 322             return;
 323         } else {
 324             p = lock_user_string(arg0);
 325             if (!p) {
 326                 /* FIXME - check error code? */
 327                 result = -1;
 328             } else {
 329                 result = unlink(p);
 330                 unlock_user(p, arg0, 0);
 331             }
 332         }
 333         break;
 334     case HOSTED_STAT:
 335         GET_ARG(0);
 336         GET_ARG(1);
 337         GET_ARG(2);
 338         if (use_gdb_syscalls()) {
 339             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
 340                            arg0, (int)arg1, arg2);
 341             return;
 342         } else {
 343             struct stat s;
 344             p = lock_user_string(arg0);
 345             if (!p) {
 346                 /* FIXME - check error code? */
 347                 result = -1;
 348             } else {
 349                 result = stat(p, &s);
 350                 unlock_user(p, arg0, 0);
 351             }
 352             if (result == 0) {
 353                 translate_stat(env, arg2, &s);
 354             }
 355         }
 356         break;
 357     case HOSTED_FSTAT:
 358         GET_ARG(0);
 359         GET_ARG(1);
 360         if (use_gdb_syscalls()) {
 361             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
 362                            arg0, arg1);
 363             return;
 364         } else {
 365             struct stat s;
 366             result = fstat(arg0, &s);
 367             if (result == 0) {
 368                 translate_stat(env, arg1, &s);
 369             }
 370         }
 371         break;
 372     case HOSTED_GETTIMEOFDAY:
 373         GET_ARG(0);
 374         GET_ARG(1);
 375         if (use_gdb_syscalls()) {
 376             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
 377                            arg0, arg1);
 378             return;
 379         } else {
 380             qemu_timeval tv;
 381             struct gdb_timeval *p;
 382             result = qemu_gettimeofday(&tv);
 383             if (result != 0) {
 384                 if (!(p = lock_user(VERIFY_WRITE,
 385                                     arg0, sizeof(struct gdb_timeval), 0))) {
 386                     /* FIXME - check error code? */
 387                     result = -1;
 388                 } else {
 389                     p->tv_sec = cpu_to_be32(tv.tv_sec);
 390                     p->tv_usec = cpu_to_be64(tv.tv_usec);
 391                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
 392                 }
 393             }
 394         }
 395         break;
 396     case HOSTED_ISATTY:
 397         GET_ARG(0);
 398         if (use_gdb_syscalls()) {
 399             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
 400             return;
 401         } else {
 402             result = isatty(arg0);
 403         }
 404         break;
 405     case HOSTED_SYSTEM:
 406         GET_ARG(0);
 407         GET_ARG(1);
 408         if (use_gdb_syscalls()) {
 409             gdb_do_syscall(m68k_semi_cb, "system,%s",
 410                            arg0, (int)arg1);
 411             return;
 412         } else {
 413             p = lock_user_string(arg0);
 414             if (!p) {
 415                 /* FIXME - check error code? */
 416                 result = -1;
 417             } else {
 418                 result = system(p);
 419                 unlock_user(p, arg0, 0);
 420             }
 421         }
 422         break;
 423     case HOSTED_INIT_SIM:
 424 #if defined(CONFIG_USER_ONLY)
 425         {
 426         CPUState *cs = env_cpu(env);
 427         TaskState *ts = cs->opaque;
 428         /* Allocate the heap using sbrk.  */
 429         if (!ts->heap_limit) {
 430             abi_ulong ret;
 431             uint32_t size;
 432             uint32_t base;
 433
 434             base = do_brk(0);
 435             size = SEMIHOSTING_HEAP_SIZE;
 436             /* Try a big heap, and reduce the size if that fails.  */
 437             for (;;) {
 438                 ret = do_brk(base + size);
 439                 if (ret >= (base + size)) {
 440                     break;
 441                 }
 442                 size >>= 1;
 443             }
 444             ts->heap_limit = base + size;
 445         }
 446         /*
 447          * This call may happen before we have writable memory, so return
 448          * values directly in registers.
 449          */
 450         env->dregs[1] = ts->heap_limit;
 451         env->aregs[7] = ts->stack_base;
 452         }
 453 #else
 454         /*
 455          * FIXME: This is wrong for boards where RAM does not start at
 456          * address zero.
 457          */
 458         env->dregs[1] = ram_size;
 459         env->aregs[7] = ram_size;
 460 #endif
 461         return;
 462     default:
 463         cpu_abort(env_cpu(env), "Unsupported semihosting syscall %d\n", nr);
 464         result = 0;
 465     }
 466 failed:
 467     m68k_semi_return_u32(env, result, errno);
 468 }