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 "sysemu/sysemu.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         /* 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         /* FIXME: We've already lost the high bits of the fseek
 163            return value.  */
 164         m68k_semi_return_u64(env, ret, err);
 165         m68k_semi_is_fseek = 0;
 166     } else {
 167         m68k_semi_return_u32(env, ret, err);
 168     }
 169 }
 170
 171 /* Read the input value from the argument block; fail the semihosting
 172  * call if the memory read fails.
 173  */
 174 #define GET_ARG(n) do {                                 \
 175     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 176         result = -1;                                    \
 177         errno = EFAULT;                                 \
 178         goto failed;                                    \
 179     }                                                   \
 180 } while (0)
 181
 182 void do_m68k_semihosting(CPUM68KState *env, int nr)
 183 {
 184     uint32_t args;
 185     target_ulong arg0, arg1, arg2, arg3;
 186     void *p;
 187     void *q;
 188     uint32_t len;
 189     uint32_t result;
 190
 191     args = env->dregs[1];
 192     switch (nr) {
 193     case HOSTED_EXIT:
 194         gdb_exit(env, env->dregs[0]);
 195         exit(env->dregs[0]);
 196     case HOSTED_OPEN:
 197         GET_ARG(0);
 198         GET_ARG(1);
 199         GET_ARG(2);
 200         GET_ARG(3);
 201         if (use_gdb_syscalls()) {
 202             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
 203                            arg2, arg3);
 204             return;
 205         } else {
 206             p = lock_user_string(arg0);
 207             if (!p) {
 208                 /* FIXME - check error code? */
 209                 result = -1;
 210             } else {
 211                 result = open(p, translate_openflags(arg2), arg3);
 212                 unlock_user(p, arg0, 0);
 213             }
 214         }
 215         break;
 216     case HOSTED_CLOSE:
 217         {
 218             /* Ignore attempts to close stdin/out/err.  */
 219             GET_ARG(0);
 220             int fd = arg0;
 221             if (fd > 2) {
 222                 if (use_gdb_syscalls()) {
 223                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
 224                     return;
 225                 } else {
 226                     result = close(fd);
 227                 }
 228             } else {
 229                 result = 0;
 230             }
 231             break;
 232         }
 233     case HOSTED_READ:
 234         GET_ARG(0);
 235         GET_ARG(1);
 236         GET_ARG(2);
 237         len = arg2;
 238         if (use_gdb_syscalls()) {
 239             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
 240                            arg0, arg1, len);
 241             return;
 242         } else {
 243             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 244             if (!p) {
 245                 /* FIXME - check error code? */
 246                 result = -1;
 247             } else {
 248                 result = read(arg0, p, len);
 249                 unlock_user(p, arg1, len);
 250             }
 251         }
 252         break;
 253     case HOSTED_WRITE:
 254         GET_ARG(0);
 255         GET_ARG(1);
 256         GET_ARG(2);
 257         len = arg2;
 258         if (use_gdb_syscalls()) {
 259             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
 260                            arg0, arg1, len);
 261             return;
 262         } else {
 263             p = lock_user(VERIFY_READ, arg1, len, 1);
 264             if (!p) {
 265                 /* FIXME - check error code? */
 266                 result = -1;
 267             } else {
 268                 result = write(arg0, p, len);
 269                 unlock_user(p, arg0, 0);
 270             }
 271         }
 272         break;
 273     case HOSTED_LSEEK:
 274         {
 275             uint64_t off;
 276             GET_ARG(0);
 277             GET_ARG(1);
 278             GET_ARG(2);
 279             GET_ARG(3);
 280             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 281             if (use_gdb_syscalls()) {
 282                 m68k_semi_is_fseek = 1;
 283                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
 284                                arg0, off, arg3);
 285             } else {
 286                 off = lseek(arg0, off, arg3);
 287                 m68k_semi_return_u64(env, off, errno);
 288             }
 289             return;
 290         }
 291     case HOSTED_RENAME:
 292         GET_ARG(0);
 293         GET_ARG(1);
 294         GET_ARG(2);
 295         GET_ARG(3);
 296         if (use_gdb_syscalls()) {
 297             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
 298                            arg0, (int)arg1, arg2, (int)arg3);
 299             return;
 300         } else {
 301             p = lock_user_string(arg0);
 302             q = lock_user_string(arg2);
 303             if (!p || !q) {
 304                 /* FIXME - check error code? */
 305                 result = -1;
 306             } else {
 307                 result = rename(p, q);
 308             }
 309             unlock_user(p, arg0, 0);
 310             unlock_user(q, arg2, 0);
 311         }
 312         break;
 313     case HOSTED_UNLINK:
 314         GET_ARG(0);
 315         GET_ARG(1);
 316         if (use_gdb_syscalls()) {
 317             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
 318                            arg0, (int)arg1);
 319             return;
 320         } else {
 321             p = lock_user_string(arg0);
 322             if (!p) {
 323                 /* FIXME - check error code? */
 324                 result = -1;
 325             } else {
 326                 result = unlink(p);
 327                 unlock_user(p, arg0, 0);
 328             }
 329         }
 330         break;
 331     case HOSTED_STAT:
 332         GET_ARG(0);
 333         GET_ARG(1);
 334         GET_ARG(2);
 335         if (use_gdb_syscalls()) {
 336             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
 337                            arg0, (int)arg1, arg2);
 338             return;
 339         } else {
 340             struct stat s;
 341             p = lock_user_string(arg0);
 342             if (!p) {
 343                 /* FIXME - check error code? */
 344                 result = -1;
 345             } else {
 346                 result = stat(p, &s);
 347                 unlock_user(p, arg0, 0);
 348             }
 349             if (result == 0) {
 350                 translate_stat(env, arg2, &s);
 351             }
 352         }
 353         break;
 354     case HOSTED_FSTAT:
 355         GET_ARG(0);
 356         GET_ARG(1);
 357         if (use_gdb_syscalls()) {
 358             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
 359                            arg0, arg1);
 360             return;
 361         } else {
 362             struct stat s;
 363             result = fstat(arg0, &s);
 364             if (result == 0) {
 365                 translate_stat(env, arg1, &s);
 366             }
 367         }
 368         break;
 369     case HOSTED_GETTIMEOFDAY:
 370         GET_ARG(0);
 371         GET_ARG(1);
 372         if (use_gdb_syscalls()) {
 373             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
 374                            arg0, arg1);
 375             return;
 376         } else {
 377             qemu_timeval tv;
 378             struct gdb_timeval *p;
 379             result = qemu_gettimeofday(&tv);
 380             if (result != 0) {
 381                 if (!(p = lock_user(VERIFY_WRITE,
 382                                     arg0, sizeof(struct gdb_timeval), 0))) {
 383                     /* FIXME - check error code? */
 384                     result = -1;
 385                 } else {
 386                     p->tv_sec = cpu_to_be32(tv.tv_sec);
 387                     p->tv_usec = cpu_to_be64(tv.tv_usec);
 388                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
 389                 }
 390             }
 391         }
 392         break;
 393     case HOSTED_ISATTY:
 394         GET_ARG(0);
 395         if (use_gdb_syscalls()) {
 396             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
 397             return;
 398         } else {
 399             result = isatty(arg0);
 400         }
 401         break;
 402     case HOSTED_SYSTEM:
 403         GET_ARG(0);
 404         GET_ARG(1);
 405         if (use_gdb_syscalls()) {
 406             gdb_do_syscall(m68k_semi_cb, "system,%s",
 407                            arg0, (int)arg1);
 408             return;
 409         } else {
 410             p = lock_user_string(arg0);
 411             if (!p) {
 412                 /* FIXME - check error code? */
 413                 result = -1;
 414             } else {
 415                 result = system(p);
 416                 unlock_user(p, arg0, 0);
 417             }
 418         }
 419         break;
 420     case HOSTED_INIT_SIM:
 421 #if defined(CONFIG_USER_ONLY)
 422         {
 423         CPUState *cs = CPU(m68k_env_get_cpu(env));
 424         TaskState *ts = cs->opaque;
 425         /* Allocate the heap using sbrk.  */
 426         if (!ts->heap_limit) {
 427             abi_ulong ret;
 428             uint32_t size;
 429             uint32_t base;
 430
 431             base = do_brk(0);
 432             size = SEMIHOSTING_HEAP_SIZE;
 433             /* Try a big heap, and reduce the size if that fails.  */
 434             for (;;) {
 435                 ret = do_brk(base + size);
 436                 if (ret >= (base + size)) {
 437                     break;
 438                 }
 439                 size >>= 1;
 440             }
 441             ts->heap_limit = base + size;
 442         }
 443         /* This call may happen before we have writable memory, so return
 444            values directly in registers.  */
 445         env->dregs[1] = ts->heap_limit;
 446         env->aregs[7] = ts->stack_base;
 447         }
 448 #else
 449         /* FIXME: This is wrong for boards where RAM does not start at
 450            address zero.  */
 451         env->dregs[1] = ram_size;
 452         env->aregs[7] = ram_size;
 453 #endif
 454         return;
 455     default:
 456         cpu_abort(CPU(m68k_env_get_cpu(env)), "Unsupported semihosting syscall %d\n", nr);
 457         result = 0;
 458     }
 459 failed:
 460     m68k_semi_return_u32(env, result, errno);
 461 }