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 "qemu-common.h"
  28 #include "exec/gdbstub.h"
  29 #include "exec/softmmu-semi.h"
  30 #endif
  31 #include "qemu/log.h"
  32 #include "sysemu/sysemu.h"
  33
  34 #define HOSTED_EXIT  0
  35 #define HOSTED_INIT_SIM 1
  36 #define HOSTED_OPEN 2
  37 #define HOSTED_CLOSE 3
  38 #define HOSTED_READ 4
  39 #define HOSTED_WRITE 5
  40 #define HOSTED_LSEEK 6
  41 #define HOSTED_RENAME 7
  42 #define HOSTED_UNLINK 8
  43 #define HOSTED_STAT 9
  44 #define HOSTED_FSTAT 10
  45 #define HOSTED_GETTIMEOFDAY 11
  46 #define HOSTED_ISATTY 12
  47 #define HOSTED_SYSTEM 13
  48
  49 typedef uint32_t gdb_mode_t;
  50 typedef uint32_t gdb_time_t;
  51
  52 struct m68k_gdb_stat {
  53   uint32_t    gdb_st_dev;     /* device */
  54   uint32_t    gdb_st_ino;     /* inode */
  55   gdb_mode_t  gdb_st_mode;    /* protection */
  56   uint32_t    gdb_st_nlink;   /* number of hard links */
  57   uint32_t    gdb_st_uid;     /* user ID of owner */
  58   uint32_t    gdb_st_gid;     /* group ID of owner */
  59   uint32_t    gdb_st_rdev;    /* device type (if inode device) */
  60   uint64_t    gdb_st_size;    /* total size, in bytes */
  61   uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
  62   uint64_t    gdb_st_blocks;  /* number of blocks allocated */
  63   gdb_time_t  gdb_st_atime;   /* time of last access */
  64   gdb_time_t  gdb_st_mtime;   /* time of last modification */
  65   gdb_time_t  gdb_st_ctime;   /* time of last change */
  66 } QEMU_PACKED;
  67
  68 struct gdb_timeval {
  69   gdb_time_t tv_sec;  /* second */
  70   uint64_t tv_usec;   /* microsecond */
  71 } QEMU_PACKED;
  72
  73 #define GDB_O_RDONLY   0x0
  74 #define GDB_O_WRONLY   0x1
  75 #define GDB_O_RDWR     0x2
  76 #define GDB_O_APPEND   0x8
  77 #define GDB_O_CREAT  0x200
  78 #define GDB_O_TRUNC  0x400
  79 #define GDB_O_EXCL   0x800
  80
  81 static int translate_openflags(int flags)
  82 {
  83     int hf;
  84
  85     if (flags & GDB_O_WRONLY)
  86         hf = O_WRONLY;
  87     else if (flags & GDB_O_RDWR)
  88         hf = O_RDWR;
  89     else
  90         hf = O_RDONLY;
  91
  92     if (flags & GDB_O_APPEND) hf |= O_APPEND;
  93     if (flags & GDB_O_CREAT) hf |= O_CREAT;
  94     if (flags & GDB_O_TRUNC) hf |= O_TRUNC;
  95     if (flags & GDB_O_EXCL) hf |= O_EXCL;
  96
  97     return hf;
  98 }
  99
 100 static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
 101 {
 102     struct m68k_gdb_stat *p;
 103
 104     if (!(p = lock_user(VERIFY_WRITE, addr, sizeof(struct m68k_gdb_stat), 0)))
 105         /* FIXME - should this return an error code? */
 106         return;
 107     p->gdb_st_dev = cpu_to_be32(s->st_dev);
 108     p->gdb_st_ino = cpu_to_be32(s->st_ino);
 109     p->gdb_st_mode = cpu_to_be32(s->st_mode);
 110     p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
 111     p->gdb_st_uid = cpu_to_be32(s->st_uid);
 112     p->gdb_st_gid = cpu_to_be32(s->st_gid);
 113     p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
 114     p->gdb_st_size = cpu_to_be64(s->st_size);
 115 #ifdef _WIN32
 116     /* Windows stat is missing some fields.  */
 117     p->gdb_st_blksize = 0;
 118     p->gdb_st_blocks = 0;
 119 #else
 120     p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
 121     p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
 122 #endif
 123     p->gdb_st_atime = cpu_to_be32(s->st_atime);
 124     p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
 125     p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
 126     unlock_user(p, addr, sizeof(struct m68k_gdb_stat));
 127 }
 128
 129 static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err)
 130 {
 131     target_ulong args = env->dregs[1];
 132     if (put_user_u32(ret, args) ||
 133         put_user_u32(err, args + 4)) {
 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         /* FIXME: We've already lost the high bits of the fseek
 164            return value.  */
 165         m68k_semi_return_u64(env, ret, err);
 166         m68k_semi_is_fseek = 0;
 167     } else {
 168         m68k_semi_return_u32(env, ret, err);
 169     }
 170 }
 171
 172 /* Read the input value from the argument block; fail the semihosting
 173  * call if the memory read fails.
 174  */
 175 #define GET_ARG(n) do {                                 \
 176     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 177         result = -1;                                    \
 178         errno = EFAULT;                                 \
 179         goto failed;                                    \
 180     }                                                   \
 181 } while (0)
 182
 183 void do_m68k_semihosting(CPUM68KState *env, int nr)
 184 {
 185     uint32_t args;
 186     target_ulong arg0, arg1, arg2, arg3;
 187     void *p;
 188     void *q;
 189     uint32_t len;
 190     uint32_t result;
 191
 192     args = env->dregs[1];
 193     switch (nr) {
 194     case HOSTED_EXIT:
 195         gdb_exit(env, env->dregs[0]);
 196         exit(env->dregs[0]);
 197     case HOSTED_OPEN:
 198         GET_ARG(0);
 199         GET_ARG(1);
 200         GET_ARG(2);
 201         GET_ARG(3);
 202         if (use_gdb_syscalls()) {
 203             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
 204                            arg2, arg3);
 205             return;
 206         } else {
 207             p = lock_user_string(arg0);
 208             if (!p) {
 209                 /* FIXME - check error code? */
 210                 result = -1;
 211             } else {
 212                 result = open(p, translate_openflags(arg2), arg3);
 213                 unlock_user(p, arg0, 0);
 214             }
 215         }
 216         break;
 217     case HOSTED_CLOSE:
 218         {
 219             /* Ignore attempts to close stdin/out/err.  */
 220             GET_ARG(0);
 221             int fd = arg0;
 222             if (fd > 2) {
 223                 if (use_gdb_syscalls()) {
 224                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
 225                     return;
 226                 } else {
 227                     result = close(fd);
 228                 }
 229             } else {
 230                 result = 0;
 231             }
 232             break;
 233         }
 234     case HOSTED_READ:
 235         GET_ARG(0);
 236         GET_ARG(1);
 237         GET_ARG(2);
 238         len = arg2;
 239         if (use_gdb_syscalls()) {
 240             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
 241                            arg0, arg1, len);
 242             return;
 243         } else {
 244             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 245             if (!p) {
 246                 /* FIXME - check error code? */
 247                 result = -1;
 248             } else {
 249                 result = read(arg0, p, len);
 250                 unlock_user(p, arg1, len);
 251             }
 252         }
 253         break;
 254     case HOSTED_WRITE:
 255         GET_ARG(0);
 256         GET_ARG(1);
 257         GET_ARG(2);
 258         len = arg2;
 259         if (use_gdb_syscalls()) {
 260             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
 261                            arg0, arg1, len);
 262             return;
 263         } else {
 264             p = lock_user(VERIFY_READ, arg1, len, 1);
 265             if (!p) {
 266                 /* FIXME - check error code? */
 267                 result = -1;
 268             } else {
 269                 result = write(arg0, p, len);
 270                 unlock_user(p, arg0, 0);
 271             }
 272         }
 273         break;
 274     case HOSTED_LSEEK:
 275         {
 276             uint64_t off;
 277             GET_ARG(0);
 278             GET_ARG(1);
 279             GET_ARG(2);
 280             GET_ARG(3);
 281             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 282             if (use_gdb_syscalls()) {
 283                 m68k_semi_is_fseek = 1;
 284                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
 285                                arg0, off, arg3);
 286             } else {
 287                 off = lseek(arg0, off, arg3);
 288                 m68k_semi_return_u64(env, off, errno);
 289             }
 290             return;
 291         }
 292     case HOSTED_RENAME:
 293         GET_ARG(0);
 294         GET_ARG(1);
 295         GET_ARG(2);
 296         GET_ARG(3);
 297         if (use_gdb_syscalls()) {
 298             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
 299                            arg0, (int)arg1, arg2, (int)arg3);
 300             return;
 301         } else {
 302             p = lock_user_string(arg0);
 303             q = lock_user_string(arg2);
 304             if (!p || !q) {
 305                 /* FIXME - check error code? */
 306                 result = -1;
 307             } else {
 308                 result = rename(p, q);
 309             }
 310             unlock_user(p, arg0, 0);
 311             unlock_user(q, arg2, 0);
 312         }
 313         break;
 314     case HOSTED_UNLINK:
 315         GET_ARG(0);
 316         GET_ARG(1);
 317         if (use_gdb_syscalls()) {
 318             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
 319                            arg0, (int)arg1);
 320             return;
 321         } else {
 322             p = lock_user_string(arg0);
 323             if (!p) {
 324                 /* FIXME - check error code? */
 325                 result = -1;
 326             } else {
 327                 result = unlink(p);
 328                 unlock_user(p, arg0, 0);
 329             }
 330         }
 331         break;
 332     case HOSTED_STAT:
 333         GET_ARG(0);
 334         GET_ARG(1);
 335         GET_ARG(2);
 336         if (use_gdb_syscalls()) {
 337             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
 338                            arg0, (int)arg1, arg2);
 339             return;
 340         } else {
 341             struct stat s;
 342             p = lock_user_string(arg0);
 343             if (!p) {
 344                 /* FIXME - check error code? */
 345                 result = -1;
 346             } else {
 347                 result = stat(p, &s);
 348                 unlock_user(p, arg0, 0);
 349             }
 350             if (result == 0) {
 351                 translate_stat(env, arg2, &s);
 352             }
 353         }
 354         break;
 355     case HOSTED_FSTAT:
 356         GET_ARG(0);
 357         GET_ARG(1);
 358         if (use_gdb_syscalls()) {
 359             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
 360                            arg0, arg1);
 361             return;
 362         } else {
 363             struct stat s;
 364             result = fstat(arg0, &s);
 365             if (result == 0) {
 366                 translate_stat(env, arg1, &s);
 367             }
 368         }
 369         break;
 370     case HOSTED_GETTIMEOFDAY:
 371         GET_ARG(0);
 372         GET_ARG(1);
 373         if (use_gdb_syscalls()) {
 374             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
 375                            arg0, arg1);
 376             return;
 377         } else {
 378             qemu_timeval tv;
 379             struct gdb_timeval *p;
 380             result = qemu_gettimeofday(&tv);
 381             if (result != 0) {
 382                 if (!(p = lock_user(VERIFY_WRITE,
 383                                     arg0, sizeof(struct gdb_timeval), 0))) {
 384                     /* FIXME - check error code? */
 385                     result = -1;
 386                 } else {
 387                     p->tv_sec = cpu_to_be32(tv.tv_sec);
 388                     p->tv_usec = cpu_to_be64(tv.tv_usec);
 389                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
 390                 }
 391             }
 392         }
 393         break;
 394     case HOSTED_ISATTY:
 395         GET_ARG(0);
 396         if (use_gdb_syscalls()) {
 397             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
 398             return;
 399         } else {
 400             result = isatty(arg0);
 401         }
 402         break;
 403     case HOSTED_SYSTEM:
 404         GET_ARG(0);
 405         GET_ARG(1);
 406         if (use_gdb_syscalls()) {
 407             gdb_do_syscall(m68k_semi_cb, "system,%s",
 408                            arg0, (int)arg1);
 409             return;
 410         } else {
 411             p = lock_user_string(arg0);
 412             if (!p) {
 413                 /* FIXME - check error code? */
 414                 result = -1;
 415             } else {
 416                 result = system(p);
 417                 unlock_user(p, arg0, 0);
 418             }
 419         }
 420         break;
 421     case HOSTED_INIT_SIM:
 422 #if defined(CONFIG_USER_ONLY)
 423         {
 424         CPUState *cs = CPU(m68k_env_get_cpu(env));
 425         TaskState *ts = cs->opaque;
 426         /* Allocate the heap using sbrk.  */
 427         if (!ts->heap_limit) {
 428             abi_ulong ret;
 429             uint32_t size;
 430             uint32_t base;
 431
 432             base = do_brk(0);
 433             size = SEMIHOSTING_HEAP_SIZE;
 434             /* Try a big heap, and reduce the size if that fails.  */
 435             for (;;) {
 436                 ret = do_brk(base + size);
 437                 if (ret >= (base + size)) {
 438                     break;
 439                 }
 440                 size >>= 1;
 441             }
 442             ts->heap_limit = base + size;
 443         }
 444         /* This call may happen before we have writable memory, so return
 445            values directly in registers.  */
 446         env->dregs[1] = ts->heap_limit;
 447         env->aregs[7] = ts->stack_base;
 448         }
 449 #else
 450         /* FIXME: This is wrong for boards where RAM does not start at
 451            address zero.  */
 452         env->dregs[1] = ram_size;
 453         env->aregs[7] = ram_size;
 454 #endif
 455         return;
 456     default:
 457         cpu_abort(CPU(m68k_env_get_cpu(env)), "Unsupported semihosting syscall %d\n", nr);
 458         result = 0;
 459     }
 460 failed:
 461     m68k_semi_return_u32(env, result, errno);
 462 }