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(CPUM68KState *env, target_ulong ret, target_ulong err)
 165 {
 166     if (m68k_semi_is_fseek) {
 167         /* FIXME: We've already lost the high bits of the fseek
 168            return value.  */
 169         m68k_semi_return_u64(env, ret, err);
 170         m68k_semi_is_fseek = 0;
 171     } else {
 172         m68k_semi_return_u32(env, ret, err);
 173     }
 174 }
 175
 176 /* Read the input value from the argument block; fail the semihosting
 177  * call if the memory read fails.
 178  */
 179 #define GET_ARG(n) do {                                 \
 180     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 181         result = -1;                                    \
 182         errno = EFAULT;                                 \
 183         goto failed;                                    \
 184     }                                                   \
 185 } while (0)
 186
 187 void do_m68k_semihosting(CPUM68KState *env, int nr)
 188 {
 189     uint32_t args;
 190     target_ulong arg0, arg1, arg2, arg3;
 191     void *p;
 192     void *q;
 193     uint32_t len;
 194     uint32_t result;
 195
 196     args = env->dregs[1];
 197     switch (nr) {
 198     case HOSTED_EXIT:
 199         gdb_exit(env, env->dregs[0]);
 200         exit(env->dregs[0]);
 201     case HOSTED_OPEN:
 202         GET_ARG(0);
 203         GET_ARG(1);
 204         GET_ARG(2);
 205         GET_ARG(3);
 206         if (use_gdb_syscalls()) {
 207             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
 208                            arg2, arg3);
 209             return;
 210         } else {
 211             p = lock_user_string(arg0);
 212             if (!p) {
 213                 /* FIXME - check error code? */
 214                 result = -1;
 215             } else {
 216                 result = open(p, translate_openflags(arg2), arg3);
 217                 unlock_user(p, arg0, 0);
 218             }
 219         }
 220         break;
 221     case HOSTED_CLOSE:
 222         {
 223             /* Ignore attempts to close stdin/out/err.  */
 224             GET_ARG(0);
 225             int fd = arg0;
 226             if (fd > 2) {
 227                 if (use_gdb_syscalls()) {
 228                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
 229                     return;
 230                 } else {
 231                     result = close(fd);
 232                 }
 233             } else {
 234                 result = 0;
 235             }
 236             break;
 237         }
 238     case HOSTED_READ:
 239         GET_ARG(0);
 240         GET_ARG(1);
 241         GET_ARG(2);
 242         len = arg2;
 243         if (use_gdb_syscalls()) {
 244             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
 245                            arg0, arg1, len);
 246             return;
 247         } else {
 248             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 249             if (!p) {
 250                 /* FIXME - check error code? */
 251                 result = -1;
 252             } else {
 253                 result = read(arg0, p, len);
 254                 unlock_user(p, arg1, len);
 255             }
 256         }
 257         break;
 258     case HOSTED_WRITE:
 259         GET_ARG(0);
 260         GET_ARG(1);
 261         GET_ARG(2);
 262         len = arg2;
 263         if (use_gdb_syscalls()) {
 264             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
 265                            arg0, arg1, len);
 266             return;
 267         } else {
 268             p = lock_user(VERIFY_READ, arg1, len, 1);
 269             if (!p) {
 270                 /* FIXME - check error code? */
 271                 result = -1;
 272             } else {
 273                 result = write(arg0, p, len);
 274                 unlock_user(p, arg0, 0);
 275             }
 276         }
 277         break;
 278     case HOSTED_LSEEK:
 279         {
 280             uint64_t off;
 281             GET_ARG(0);
 282             GET_ARG(1);
 283             GET_ARG(2);
 284             GET_ARG(3);
 285             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 286             if (use_gdb_syscalls()) {
 287                 m68k_semi_is_fseek = 1;
 288                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
 289                                arg0, off, arg3);
 290             } else {
 291                 off = lseek(arg0, off, arg3);
 292                 m68k_semi_return_u64(env, off, errno);
 293             }
 294             return;
 295         }
 296     case HOSTED_RENAME:
 297         GET_ARG(0);
 298         GET_ARG(1);
 299         GET_ARG(2);
 300         GET_ARG(3);
 301         if (use_gdb_syscalls()) {
 302             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
 303                            arg0, (int)arg1, arg2, (int)arg3);
 304             return;
 305         } else {
 306             p = lock_user_string(arg0);
 307             q = lock_user_string(arg2);
 308             if (!p || !q) {
 309                 /* FIXME - check error code? */
 310                 result = -1;
 311             } else {
 312                 result = rename(p, q);
 313             }
 314             unlock_user(p, arg0, 0);
 315             unlock_user(q, arg2, 0);
 316         }
 317         break;
 318     case HOSTED_UNLINK:
 319         GET_ARG(0);
 320         GET_ARG(1);
 321         if (use_gdb_syscalls()) {
 322             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
 323                            arg0, (int)arg1);
 324             return;
 325         } else {
 326             p = lock_user_string(arg0);
 327             if (!p) {
 328                 /* FIXME - check error code? */
 329                 result = -1;
 330             } else {
 331                 result = unlink(p);
 332                 unlock_user(p, arg0, 0);
 333             }
 334         }
 335         break;
 336     case HOSTED_STAT:
 337         GET_ARG(0);
 338         GET_ARG(1);
 339         GET_ARG(2);
 340         if (use_gdb_syscalls()) {
 341             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
 342                            arg0, (int)arg1, arg2);
 343             return;
 344         } else {
 345             struct stat s;
 346             p = lock_user_string(arg0);
 347             if (!p) {
 348                 /* FIXME - check error code? */
 349                 result = -1;
 350             } else {
 351                 result = stat(p, &s);
 352                 unlock_user(p, arg0, 0);
 353             }
 354             if (result == 0) {
 355                 translate_stat(env, arg2, &s);
 356             }
 357         }
 358         break;
 359     case HOSTED_FSTAT:
 360         GET_ARG(0);
 361         GET_ARG(1);
 362         if (use_gdb_syscalls()) {
 363             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
 364                            arg0, arg1);
 365             return;
 366         } else {
 367             struct stat s;
 368             result = fstat(arg0, &s);
 369             if (result == 0) {
 370                 translate_stat(env, arg1, &s);
 371             }
 372         }
 373         break;
 374     case HOSTED_GETTIMEOFDAY:
 375         GET_ARG(0);
 376         GET_ARG(1);
 377         if (use_gdb_syscalls()) {
 378             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
 379                            arg0, arg1);
 380             return;
 381         } else {
 382             qemu_timeval tv;
 383             struct gdb_timeval *p;
 384             result = qemu_gettimeofday(&tv);
 385             if (result != 0) {
 386                 if (!(p = lock_user(VERIFY_WRITE,
 387                                     arg0, sizeof(struct gdb_timeval), 0))) {
 388                     /* FIXME - check error code? */
 389                     result = -1;
 390                 } else {
 391                     p->tv_sec = cpu_to_be32(tv.tv_sec);
 392                     p->tv_usec = cpu_to_be64(tv.tv_usec);
 393                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
 394                 }
 395             }
 396         }
 397         break;
 398     case HOSTED_ISATTY:
 399         GET_ARG(0);
 400         if (use_gdb_syscalls()) {
 401             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
 402             return;
 403         } else {
 404             result = isatty(arg0);
 405         }
 406         break;
 407     case HOSTED_SYSTEM:
 408         GET_ARG(0);
 409         GET_ARG(1);
 410         if (use_gdb_syscalls()) {
 411             gdb_do_syscall(m68k_semi_cb, "system,%s",
 412                            arg0, (int)arg1);
 413             return;
 414         } else {
 415             p = lock_user_string(arg0);
 416             if (!p) {
 417                 /* FIXME - check error code? */
 418                 result = -1;
 419             } else {
 420                 result = system(p);
 421                 unlock_user(p, arg0, 0);
 422             }
 423         }
 424         break;
 425     case HOSTED_INIT_SIM:
 426 #if defined(CONFIG_USER_ONLY)
 427         {
 428         TaskState *ts = env->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         /* This call may happen before we have writable memory, so return
 448            values directly in registers.  */
 449         env->dregs[1] = ts->heap_limit;
 450         env->aregs[7] = ts->stack_base;
 451         }
 452 #else
 453         /* FIXME: This is wrong for boards where RAM does not start at
 454            address zero.  */
 455         env->dregs[1] = ram_size;
 456         env->aregs[7] = ram_size;
 457 #endif
 458         return;
 459     default:
 460         cpu_abort(env, "Unsupported semihosting syscall %d\n", nr);
 461         result = 0;
 462     }
 463 failed:
 464     m68k_semi_return_u32(env, result, errno);
 465 }