qemu/target/m68k/m68k-semi.c
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   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
  49typedef uint32_t gdb_mode_t;
  50typedef uint32_t gdb_time_t;
  51
  52struct 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
  68struct 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
  81static 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
 100static 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
 129static 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
 143static 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
 155static int m68k_semi_is_fseek;
 156
 157static 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
 183void 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    }
 460failed:
 461    m68k_semi_return_u32(env, result, errno);
 462}
 463