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 #include "hw/boards.h"
  30 #endif
  31 #include "qemu/log.h"
  32
  33 #define HOSTED_EXIT  0
  34 #define HOSTED_INIT_SIM 1
  35 #define HOSTED_OPEN 2
  36 #define HOSTED_CLOSE 3
  37 #define HOSTED_READ 4
  38 #define HOSTED_WRITE 5
  39 #define HOSTED_LSEEK 6
  40 #define HOSTED_RENAME 7
  41 #define HOSTED_UNLINK 8
  42 #define HOSTED_STAT 9
  43 #define HOSTED_FSTAT 10
  44 #define HOSTED_GETTIMEOFDAY 11
  45 #define HOSTED_ISATTY 12
  46 #define HOSTED_SYSTEM 13
  47
  48 typedef uint32_t gdb_mode_t;
  49 typedef uint32_t gdb_time_t;
  50
  51 struct m68k_gdb_stat {
  52   uint32_t    gdb_st_dev;     /* device */
  53   uint32_t    gdb_st_ino;     /* inode */
  54   gdb_mode_t  gdb_st_mode;    /* protection */
  55   uint32_t    gdb_st_nlink;   /* number of hard links */
  56   uint32_t    gdb_st_uid;     /* user ID of owner */
  57   uint32_t    gdb_st_gid;     /* group ID of owner */
  58   uint32_t    gdb_st_rdev;    /* device type (if inode device) */
  59   uint64_t    gdb_st_size;    /* total size, in bytes */
  60   uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
  61   uint64_t    gdb_st_blocks;  /* number of blocks allocated */
  62   gdb_time_t  gdb_st_atime;   /* time of last access */
  63   gdb_time_t  gdb_st_mtime;   /* time of last modification */
  64   gdb_time_t  gdb_st_ctime;   /* time of last change */
  65 } QEMU_PACKED;
  66
  67 struct gdb_timeval {
  68   gdb_time_t tv_sec;  /* second */
  69   uint64_t tv_usec;   /* microsecond */
  70 } QEMU_PACKED;
  71
  72 #define GDB_O_RDONLY   0x0
  73 #define GDB_O_WRONLY   0x1
  74 #define GDB_O_RDWR     0x2
  75 #define GDB_O_APPEND   0x8
  76 #define GDB_O_CREAT  0x200
  77 #define GDB_O_TRUNC  0x400
  78 #define GDB_O_EXCL   0x800
  79
  80 static int translate_openflags(int flags)
  81 {
  82     int hf;
  83
  84     if (flags & GDB_O_WRONLY)
  85         hf = O_WRONLY;
  86     else if (flags & GDB_O_RDWR)
  87         hf = O_RDWR;
  88     else
  89         hf = O_RDONLY;
  90
  91     if (flags & GDB_O_APPEND) hf |= O_APPEND;
  92     if (flags & GDB_O_CREAT) hf |= O_CREAT;
  93     if (flags & GDB_O_TRUNC) hf |= O_TRUNC;
  94     if (flags & GDB_O_EXCL) hf |= O_EXCL;
  95
  96     return hf;
  97 }
  98
  99 static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
 100 {
 101     struct m68k_gdb_stat *p;
 102
 103     if (!(p = lock_user(VERIFY_WRITE, addr, sizeof(struct m68k_gdb_stat), 0)))
 104         /* FIXME - should this return an error code? */
 105         return;
 106     p->gdb_st_dev = cpu_to_be32(s->st_dev);
 107     p->gdb_st_ino = cpu_to_be32(s->st_ino);
 108     p->gdb_st_mode = cpu_to_be32(s->st_mode);
 109     p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
 110     p->gdb_st_uid = cpu_to_be32(s->st_uid);
 111     p->gdb_st_gid = cpu_to_be32(s->st_gid);
 112     p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
 113     p->gdb_st_size = cpu_to_be64(s->st_size);
 114 #ifdef _WIN32
 115     /* Windows stat is missing some fields.  */
 116     p->gdb_st_blksize = 0;
 117     p->gdb_st_blocks = 0;
 118 #else
 119     p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
 120     p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
 121 #endif
 122     p->gdb_st_atime = cpu_to_be32(s->st_atime);
 123     p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
 124     p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
 125     unlock_user(p, addr, sizeof(struct m68k_gdb_stat));
 126 }
 127
 128 static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err)
 129 {
 130     target_ulong args = env->dregs[1];
 131     if (put_user_u32(ret, args) ||
 132         put_user_u32(err, args + 4)) {
 133         /*
 134          * The m68k semihosting ABI does not provide any way to report this
 135          * error to the guest, so the best we can do is log it in qemu.
 136          * It is always a guest error not to pass us a valid argument block.
 137          */
 138         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 139                       "discarded because argument block not writable\n");
 140     }
 141 }
 142
 143 static void m68k_semi_return_u64(CPUM68KState *env, uint64_t ret, uint32_t err)
 144 {
 145     target_ulong args = env->dregs[1];
 146     if (put_user_u32(ret >> 32, args) ||
 147         put_user_u32(ret, args + 4) ||
 148         put_user_u32(err, args + 8)) {
 149         /* No way to report this via m68k semihosting ABI; just log it */
 150         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 151                       "discarded because argument block not writable\n");
 152     }
 153 }
 154
 155 static int m68k_semi_is_fseek;
 156
 157 static void m68k_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
 158 {
 159     M68kCPU *cpu = M68K_CPU(cs);
 160     CPUM68KState *env = &cpu->env;
 161
 162     if (m68k_semi_is_fseek) {
 163         /*
 164          * FIXME: We've already lost the high bits of the fseek
 165          * return value.
 166          */
 167         m68k_semi_return_u64(env, ret, err);
 168         m68k_semi_is_fseek = 0;
 169     } else {
 170         m68k_semi_return_u32(env, ret, err);
 171     }
 172 }
 173
 174 /*
 175  * Read the input value from the argument block; fail the semihosting
 176  * call if the memory read fails.
 177  */
 178 #define GET_ARG(n) do {                                 \
 179     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 180         result = -1;                                    \
 181         errno = EFAULT;                                 \
 182         goto failed;                                    \
 183     }                                                   \
 184 } while (0)
 185
 186 void do_m68k_semihosting(CPUM68KState *env, int nr)
 187 {
 188     uint32_t args;
 189     target_ulong arg0, arg1, arg2, arg3;
 190     void *p;
 191     void *q;
 192     uint32_t len;
 193     uint32_t result;
 194
 195     args = env->dregs[1];
 196     switch (nr) {
 197     case HOSTED_EXIT:
 198         gdb_exit(env->dregs[0]);
 199         exit(env->dregs[0]);
 200     case HOSTED_OPEN:
 201         GET_ARG(0);
 202         GET_ARG(1);
 203         GET_ARG(2);
 204         GET_ARG(3);
 205         if (use_gdb_syscalls()) {
 206             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
 207                            arg2, arg3);
 208             return;
 209         } else {
 210             p = lock_user_string(arg0);
 211             if (!p) {
 212                 /* FIXME - check error code? */
 213                 result = -1;
 214             } else {
 215                 result = open(p, translate_openflags(arg2), arg3);
 216                 unlock_user(p, arg0, 0);
 217             }
 218         }
 219         break;
 220     case HOSTED_CLOSE:
 221         {
 222             /* Ignore attempts to close stdin/out/err.  */
 223             GET_ARG(0);
 224             int fd = arg0;
 225             if (fd > 2) {
 226                 if (use_gdb_syscalls()) {
 227                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
 228                     return;
 229                 } else {
 230                     result = close(fd);
 231                 }
 232             } else {
 233                 result = 0;
 234             }
 235             break;
 236         }
 237     case HOSTED_READ:
 238         GET_ARG(0);
 239         GET_ARG(1);
 240         GET_ARG(2);
 241         len = arg2;
 242         if (use_gdb_syscalls()) {
 243             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
 244                            arg0, arg1, len);
 245             return;
 246         } else {
 247             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 248             if (!p) {
 249                 /* FIXME - check error code? */
 250                 result = -1;
 251             } else {
 252                 result = read(arg0, p, len);
 253                 unlock_user(p, arg1, len);
 254             }
 255         }
 256         break;
 257     case HOSTED_WRITE:
 258         GET_ARG(0);
 259         GET_ARG(1);
 260         GET_ARG(2);
 261         len = arg2;
 262         if (use_gdb_syscalls()) {
 263             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
 264                            arg0, arg1, len);
 265             return;
 266         } else {
 267             p = lock_user(VERIFY_READ, arg1, len, 1);
 268             if (!p) {
 269                 /* FIXME - check error code? */
 270                 result = -1;
 271             } else {
 272                 result = write(arg0, p, len);
 273                 unlock_user(p, arg0, 0);
 274             }
 275         }
 276         break;
 277     case HOSTED_LSEEK:
 278         {
 279             uint64_t off;
 280             GET_ARG(0);
 281             GET_ARG(1);
 282             GET_ARG(2);
 283             GET_ARG(3);
 284             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 285             if (use_gdb_syscalls()) {
 286                 m68k_semi_is_fseek = 1;
 287                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
 288                                arg0, off, arg3);
 289             } else {
 290                 off = lseek(arg0, off, arg3);
 291                 m68k_semi_return_u64(env, off, errno);
 292             }
 293             return;
 294         }
 295     case HOSTED_RENAME:
 296         GET_ARG(0);
 297         GET_ARG(1);
 298         GET_ARG(2);
 299         GET_ARG(3);
 300         if (use_gdb_syscalls()) {
 301             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
 302                            arg0, (int)arg1, arg2, (int)arg3);
 303             return;
 304         } else {
 305             p = lock_user_string(arg0);
 306             q = lock_user_string(arg2);
 307             if (!p || !q) {
 308                 /* FIXME - check error code? */
 309                 result = -1;
 310             } else {
 311                 result = rename(p, q);
 312             }
 313             unlock_user(p, arg0, 0);
 314             unlock_user(q, arg2, 0);
 315         }
 316         break;
 317     case HOSTED_UNLINK:
 318         GET_ARG(0);
 319         GET_ARG(1);
 320         if (use_gdb_syscalls()) {
 321             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
 322                            arg0, (int)arg1);
 323             return;
 324         } else {
 325             p = lock_user_string(arg0);
 326             if (!p) {
 327                 /* FIXME - check error code? */
 328                 result = -1;
 329             } else {
 330                 result = unlink(p);
 331                 unlock_user(p, arg0, 0);
 332             }
 333         }
 334         break;
 335     case HOSTED_STAT:
 336         GET_ARG(0);
 337         GET_ARG(1);
 338         GET_ARG(2);
 339         if (use_gdb_syscalls()) {
 340             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
 341                            arg0, (int)arg1, arg2);
 342             return;
 343         } else {
 344             struct stat s;
 345             p = lock_user_string(arg0);
 346             if (!p) {
 347                 /* FIXME - check error code? */
 348                 result = -1;
 349             } else {
 350                 result = stat(p, &s);
 351                 unlock_user(p, arg0, 0);
 352             }
 353             if (result == 0) {
 354                 translate_stat(env, arg2, &s);
 355             }
 356         }
 357         break;
 358     case HOSTED_FSTAT:
 359         GET_ARG(0);
 360         GET_ARG(1);
 361         if (use_gdb_syscalls()) {
 362             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
 363                            arg0, arg1);
 364             return;
 365         } else {
 366             struct stat s;
 367             result = fstat(arg0, &s);
 368             if (result == 0) {
 369                 translate_stat(env, arg1, &s);
 370             }
 371         }
 372         break;
 373     case HOSTED_GETTIMEOFDAY:
 374         GET_ARG(0);
 375         GET_ARG(1);
 376         if (use_gdb_syscalls()) {
 377             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
 378                            arg0, arg1);
 379             return;
 380         } else {
 381             qemu_timeval tv;
 382             struct gdb_timeval *p;
 383             result = qemu_gettimeofday(&tv);
 384             if (result != 0) {
 385                 if (!(p = lock_user(VERIFY_WRITE,
 386                                     arg0, sizeof(struct gdb_timeval), 0))) {
 387                     /* FIXME - check error code? */
 388                     result = -1;
 389                 } else {
 390                     p->tv_sec = cpu_to_be32(tv.tv_sec);
 391                     p->tv_usec = cpu_to_be64(tv.tv_usec);
 392                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
 393                 }
 394             }
 395         }
 396         break;
 397     case HOSTED_ISATTY:
 398         GET_ARG(0);
 399         if (use_gdb_syscalls()) {
 400             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
 401             return;
 402         } else {
 403             result = isatty(arg0);
 404         }
 405         break;
 406     case HOSTED_SYSTEM:
 407         GET_ARG(0);
 408         GET_ARG(1);
 409         if (use_gdb_syscalls()) {
 410             gdb_do_syscall(m68k_semi_cb, "system,%s",
 411                            arg0, (int)arg1);
 412             return;
 413         } else {
 414             p = lock_user_string(arg0);
 415             if (!p) {
 416                 /* FIXME - check error code? */
 417                 result = -1;
 418             } else {
 419                 result = system(p);
 420                 unlock_user(p, arg0, 0);
 421             }
 422         }
 423         break;
 424     case HOSTED_INIT_SIM:
 425 #if defined(CONFIG_USER_ONLY)
 426         {
 427         CPUState *cs = env_cpu(env);
 428         TaskState *ts = cs->opaque;
 429         /* Allocate the heap using sbrk.  */
 430         if (!ts->heap_limit) {
 431             abi_ulong ret;
 432             uint32_t size;
 433             uint32_t base;
 434
 435             base = do_brk(0);
 436             size = SEMIHOSTING_HEAP_SIZE;
 437             /* Try a big heap, and reduce the size if that fails.  */
 438             for (;;) {
 439                 ret = do_brk(base + size);
 440                 if (ret >= (base + size)) {
 441                     break;
 442                 }
 443                 size >>= 1;
 444             }
 445             ts->heap_limit = base + size;
 446         }
 447         /*
 448          * This call may happen before we have writable memory, so return
 449          * values directly in registers.
 450          */
 451         env->dregs[1] = ts->heap_limit;
 452         env->aregs[7] = ts->stack_base;
 453         }
 454 #else
 455         /*
 456          * FIXME: This is wrong for boards where RAM does not start at
 457          * address zero.
 458          */
 459         env->dregs[1] = current_machine->ram_size;
 460         env->aregs[7] = current_machine->ram_size;
 461 #endif
 462         return;
 463     default:
 464         cpu_abort(env_cpu(env), "Unsupported semihosting syscall %d\n", nr);
 465         result = 0;
 466     }
 467 failed:
 468     m68k_semi_return_u32(env, result, errno);
 469 }