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 <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <sys/time.h>
  28 #include <time.h>
  29
  30 #include "cpu.h"
  31 #if defined(CONFIG_USER_ONLY)
  32 #include "qemu.h"
  33 #define SEMIHOSTING_HEAP_SIZE (128 * 1024 * 1024)
  34 #else
  35 #include "qemu-common.h"
  36 #include "exec/gdbstub.h"
  37 #include "exec/softmmu-semi.h"
  38 #endif
  39 #include "sysemu/sysemu.h"
  40
  41 #define HOSTED_EXIT  0
  42 #define HOSTED_INIT_SIM 1
  43 #define HOSTED_OPEN 2
  44 #define HOSTED_CLOSE 3
  45 #define HOSTED_READ 4
  46 #define HOSTED_WRITE 5
  47 #define HOSTED_LSEEK 6
  48 #define HOSTED_RENAME 7
  49 #define HOSTED_UNLINK 8
  50 #define HOSTED_STAT 9
  51 #define HOSTED_FSTAT 10
  52 #define HOSTED_GETTIMEOFDAY 11
  53 #define HOSTED_ISATTY 12
  54 #define HOSTED_SYSTEM 13
  55
  56 typedef uint32_t gdb_mode_t;
  57 typedef uint32_t gdb_time_t;
  58
  59 struct m68k_gdb_stat {
  60   uint32_t    gdb_st_dev;     /* device */
  61   uint32_t    gdb_st_ino;     /* inode */
  62   gdb_mode_t  gdb_st_mode;    /* protection */
  63   uint32_t    gdb_st_nlink;   /* number of hard links */
  64   uint32_t    gdb_st_uid;     /* user ID of owner */
  65   uint32_t    gdb_st_gid;     /* group ID of owner */
  66   uint32_t    gdb_st_rdev;    /* device type (if inode device) */
  67   uint64_t    gdb_st_size;    /* total size, in bytes */
  68   uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
  69   uint64_t    gdb_st_blocks;  /* number of blocks allocated */
  70   gdb_time_t  gdb_st_atime;   /* time of last access */
  71   gdb_time_t  gdb_st_mtime;   /* time of last modification */
  72   gdb_time_t  gdb_st_ctime;   /* time of last change */
  73 } QEMU_PACKED;
  74
  75 struct gdb_timeval {
  76   gdb_time_t tv_sec;  /* second */
  77   uint64_t tv_usec;   /* microsecond */
  78 } QEMU_PACKED;
  79
  80 #define GDB_O_RDONLY   0x0
  81 #define GDB_O_WRONLY   0x1
  82 #define GDB_O_RDWR     0x2
  83 #define GDB_O_APPEND   0x8
  84 #define GDB_O_CREAT  0x200
  85 #define GDB_O_TRUNC  0x400
  86 #define GDB_O_EXCL   0x800
  87
  88 static int translate_openflags(int flags)
  89 {
  90     int hf;
  91
  92     if (flags & GDB_O_WRONLY)
  93         hf = O_WRONLY;
  94     else if (flags & GDB_O_RDWR)
  95         hf = O_RDWR;
  96     else
  97         hf = O_RDONLY;
  98
  99     if (flags & GDB_O_APPEND) hf |= O_APPEND;
 100     if (flags & GDB_O_CREAT) hf |= O_CREAT;
 101     if (flags & GDB_O_TRUNC) hf |= O_TRUNC;
 102     if (flags & GDB_O_EXCL) hf |= O_EXCL;
 103
 104     return hf;
 105 }
 106
 107 static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
 108 {
 109     struct m68k_gdb_stat *p;
 110
 111     if (!(p = lock_user(VERIFY_WRITE, addr, sizeof(struct m68k_gdb_stat), 0)))
 112         /* FIXME - should this return an error code? */
 113         return;
 114     p->gdb_st_dev = cpu_to_be32(s->st_dev);
 115     p->gdb_st_ino = cpu_to_be32(s->st_ino);
 116     p->gdb_st_mode = cpu_to_be32(s->st_mode);
 117     p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
 118     p->gdb_st_uid = cpu_to_be32(s->st_uid);
 119     p->gdb_st_gid = cpu_to_be32(s->st_gid);
 120     p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
 121     p->gdb_st_size = cpu_to_be64(s->st_size);
 122 #ifdef _WIN32
 123     /* Windows stat is missing some fields.  */
 124     p->gdb_st_blksize = 0;
 125     p->gdb_st_blocks = 0;
 126 #else
 127     p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
 128     p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
 129 #endif
 130     p->gdb_st_atime = cpu_to_be32(s->st_atime);
 131     p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
 132     p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
 133     unlock_user(p, addr, sizeof(struct m68k_gdb_stat));
 134 }
 135
 136 static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err)
 137 {
 138     target_ulong args = env->dregs[1];
 139     if (put_user_u32(ret, args) ||
 140         put_user_u32(err, args + 4)) {
 141         /* The m68k semihosting ABI does not provide any way to report this
 142          * error to the guest, so the best we can do is log it in qemu.
 143          * It is always a guest error not to pass us a valid argument block.
 144          */
 145         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 146                       "discarded because argument block not writable\n");
 147     }
 148 }
 149
 150 static void m68k_semi_return_u64(CPUM68KState *env, uint64_t ret, uint32_t err)
 151 {
 152     target_ulong args = env->dregs[1];
 153     if (put_user_u32(ret >> 32, args) ||
 154         put_user_u32(ret, args + 4) ||
 155         put_user_u32(err, args + 8)) {
 156         /* No way to report this via m68k semihosting ABI; just log it */
 157         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 158                       "discarded because argument block not writable\n");
 159     }
 160 }
 161
 162 static int m68k_semi_is_fseek;
 163
 164 static void m68k_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
 165 {
 166     M68kCPU *cpu = M68K_CPU(cs);
 167     CPUM68KState *env = &cpu->env;
 168
 169     if (m68k_semi_is_fseek) {
 170         /* FIXME: We've already lost the high bits of the fseek
 171            return value.  */
 172         m68k_semi_return_u64(env, ret, err);
 173         m68k_semi_is_fseek = 0;
 174     } else {
 175         m68k_semi_return_u32(env, ret, err);
 176     }
 177 }
 178
 179 /* Read the input value from the argument block; fail the semihosting
 180  * call if the memory read fails.
 181  */
 182 #define GET_ARG(n) do {                                 \
 183     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 184         result = -1;                                    \
 185         errno = EFAULT;                                 \
 186         goto failed;                                    \
 187     }                                                   \
 188 } while (0)
 189
 190 void do_m68k_semihosting(CPUM68KState *env, int nr)
 191 {
 192     uint32_t args;
 193     target_ulong arg0, arg1, arg2, arg3;
 194     void *p;
 195     void *q;
 196     uint32_t len;
 197     uint32_t result;
 198
 199     args = env->dregs[1];
 200     switch (nr) {
 201     case HOSTED_EXIT:
 202         gdb_exit(env, env->dregs[0]);
 203         exit(env->dregs[0]);
 204     case HOSTED_OPEN:
 205         GET_ARG(0);
 206         GET_ARG(1);
 207         GET_ARG(2);
 208         GET_ARG(3);
 209         if (use_gdb_syscalls()) {
 210             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
 211                            arg2, arg3);
 212             return;
 213         } else {
 214             p = lock_user_string(arg0);
 215             if (!p) {
 216                 /* FIXME - check error code? */
 217                 result = -1;
 218             } else {
 219                 result = open(p, translate_openflags(arg2), arg3);
 220                 unlock_user(p, arg0, 0);
 221             }
 222         }
 223         break;
 224     case HOSTED_CLOSE:
 225         {
 226             /* Ignore attempts to close stdin/out/err.  */
 227             GET_ARG(0);
 228             int fd = arg0;
 229             if (fd > 2) {
 230                 if (use_gdb_syscalls()) {
 231                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
 232                     return;
 233                 } else {
 234                     result = close(fd);
 235                 }
 236             } else {
 237                 result = 0;
 238             }
 239             break;
 240         }
 241     case HOSTED_READ:
 242         GET_ARG(0);
 243         GET_ARG(1);
 244         GET_ARG(2);
 245         len = arg2;
 246         if (use_gdb_syscalls()) {
 247             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
 248                            arg0, arg1, len);
 249             return;
 250         } else {
 251             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 252             if (!p) {
 253                 /* FIXME - check error code? */
 254                 result = -1;
 255             } else {
 256                 result = read(arg0, p, len);
 257                 unlock_user(p, arg1, len);
 258             }
 259         }
 260         break;
 261     case HOSTED_WRITE:
 262         GET_ARG(0);
 263         GET_ARG(1);
 264         GET_ARG(2);
 265         len = arg2;
 266         if (use_gdb_syscalls()) {
 267             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
 268                            arg0, arg1, len);
 269             return;
 270         } else {
 271             p = lock_user(VERIFY_READ, arg1, len, 1);
 272             if (!p) {
 273                 /* FIXME - check error code? */
 274                 result = -1;
 275             } else {
 276                 result = write(arg0, p, len);
 277                 unlock_user(p, arg0, 0);
 278             }
 279         }
 280         break;
 281     case HOSTED_LSEEK:
 282         {
 283             uint64_t off;
 284             GET_ARG(0);
 285             GET_ARG(1);
 286             GET_ARG(2);
 287             GET_ARG(3);
 288             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 289             if (use_gdb_syscalls()) {
 290                 m68k_semi_is_fseek = 1;
 291                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
 292                                arg0, off, arg3);
 293             } else {
 294                 off = lseek(arg0, off, arg3);
 295                 m68k_semi_return_u64(env, off, errno);
 296             }
 297             return;
 298         }
 299     case HOSTED_RENAME:
 300         GET_ARG(0);
 301         GET_ARG(1);
 302         GET_ARG(2);
 303         GET_ARG(3);
 304         if (use_gdb_syscalls()) {
 305             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
 306                            arg0, (int)arg1, arg2, (int)arg3);
 307             return;
 308         } else {
 309             p = lock_user_string(arg0);
 310             q = lock_user_string(arg2);
 311             if (!p || !q) {
 312                 /* FIXME - check error code? */
 313                 result = -1;
 314             } else {
 315                 result = rename(p, q);
 316             }
 317             unlock_user(p, arg0, 0);
 318             unlock_user(q, arg2, 0);
 319         }
 320         break;
 321     case HOSTED_UNLINK:
 322         GET_ARG(0);
 323         GET_ARG(1);
 324         if (use_gdb_syscalls()) {
 325             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
 326                            arg0, (int)arg1);
 327             return;
 328         } else {
 329             p = lock_user_string(arg0);
 330             if (!p) {
 331                 /* FIXME - check error code? */
 332                 result = -1;
 333             } else {
 334                 result = unlink(p);
 335                 unlock_user(p, arg0, 0);
 336             }
 337         }
 338         break;
 339     case HOSTED_STAT:
 340         GET_ARG(0);
 341         GET_ARG(1);
 342         GET_ARG(2);
 343         if (use_gdb_syscalls()) {
 344             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
 345                            arg0, (int)arg1, arg2);
 346             return;
 347         } else {
 348             struct stat s;
 349             p = lock_user_string(arg0);
 350             if (!p) {
 351                 /* FIXME - check error code? */
 352                 result = -1;
 353             } else {
 354                 result = stat(p, &s);
 355                 unlock_user(p, arg0, 0);
 356             }
 357             if (result == 0) {
 358                 translate_stat(env, arg2, &s);
 359             }
 360         }
 361         break;
 362     case HOSTED_FSTAT:
 363         GET_ARG(0);
 364         GET_ARG(1);
 365         if (use_gdb_syscalls()) {
 366             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
 367                            arg0, arg1);
 368             return;
 369         } else {
 370             struct stat s;
 371             result = fstat(arg0, &s);
 372             if (result == 0) {
 373                 translate_stat(env, arg1, &s);
 374             }
 375         }
 376         break;
 377     case HOSTED_GETTIMEOFDAY:
 378         GET_ARG(0);
 379         GET_ARG(1);
 380         if (use_gdb_syscalls()) {
 381             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
 382                            arg0, arg1);
 383             return;
 384         } else {
 385             qemu_timeval tv;
 386             struct gdb_timeval *p;
 387             result = qemu_gettimeofday(&tv);
 388             if (result != 0) {
 389                 if (!(p = lock_user(VERIFY_WRITE,
 390                                     arg0, sizeof(struct gdb_timeval), 0))) {
 391                     /* FIXME - check error code? */
 392                     result = -1;
 393                 } else {
 394                     p->tv_sec = cpu_to_be32(tv.tv_sec);
 395                     p->tv_usec = cpu_to_be64(tv.tv_usec);
 396                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
 397                 }
 398             }
 399         }
 400         break;
 401     case HOSTED_ISATTY:
 402         GET_ARG(0);
 403         if (use_gdb_syscalls()) {
 404             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
 405             return;
 406         } else {
 407             result = isatty(arg0);
 408         }
 409         break;
 410     case HOSTED_SYSTEM:
 411         GET_ARG(0);
 412         GET_ARG(1);
 413         if (use_gdb_syscalls()) {
 414             gdb_do_syscall(m68k_semi_cb, "system,%s",
 415                            arg0, (int)arg1);
 416             return;
 417         } else {
 418             p = lock_user_string(arg0);
 419             if (!p) {
 420                 /* FIXME - check error code? */
 421                 result = -1;
 422             } else {
 423                 result = system(p);
 424                 unlock_user(p, arg0, 0);
 425             }
 426         }
 427         break;
 428     case HOSTED_INIT_SIM:
 429 #if defined(CONFIG_USER_ONLY)
 430         {
 431         CPUState *cs = CPU(m68k_env_get_cpu(env));
 432         TaskState *ts = cs->opaque;
 433         /* Allocate the heap using sbrk.  */
 434         if (!ts->heap_limit) {
 435             abi_ulong ret;
 436             uint32_t size;
 437             uint32_t base;
 438
 439             base = do_brk(0);
 440             size = SEMIHOSTING_HEAP_SIZE;
 441             /* Try a big heap, and reduce the size if that fails.  */
 442             for (;;) {
 443                 ret = do_brk(base + size);
 444                 if (ret >= (base + size)) {
 445                     break;
 446                 }
 447                 size >>= 1;
 448             }
 449             ts->heap_limit = base + size;
 450         }
 451         /* This call may happen before we have writable memory, so return
 452            values directly in registers.  */
 453         env->dregs[1] = ts->heap_limit;
 454         env->aregs[7] = ts->stack_base;
 455         }
 456 #else
 457         /* FIXME: This is wrong for boards where RAM does not start at
 458            address zero.  */
 459         env->dregs[1] = ram_size;
 460         env->aregs[7] = ram_size;
 461 #endif
 462         return;
 463     default:
 464         cpu_abort(env, "Unsupported semihosting syscall %d\n", nr);
 465         result = 0;
 466     }
 467 failed:
 468     m68k_semi_return_u32(env, result, errno);
 469 }