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 #include "exec/gdbstub.h"
  24 #include "semihosting/softmmu-uaccess.h"
  25 #include "hw/boards.h"
  26 #include "qemu/log.h"
  27
  28 #define HOSTED_EXIT  0
  29 #define HOSTED_INIT_SIM 1
  30 #define HOSTED_OPEN 2
  31 #define HOSTED_CLOSE 3
  32 #define HOSTED_READ 4
  33 #define HOSTED_WRITE 5
  34 #define HOSTED_LSEEK 6
  35 #define HOSTED_RENAME 7
  36 #define HOSTED_UNLINK 8
  37 #define HOSTED_STAT 9
  38 #define HOSTED_FSTAT 10
  39 #define HOSTED_GETTIMEOFDAY 11
  40 #define HOSTED_ISATTY 12
  41 #define HOSTED_SYSTEM 13
  42
  43 static int translate_openflags(int flags)
  44 {
  45     int hf;
  46
  47     if (flags & GDB_O_WRONLY)
  48         hf = O_WRONLY;
  49     else if (flags & GDB_O_RDWR)
  50         hf = O_RDWR;
  51     else
  52         hf = O_RDONLY;
  53
  54     if (flags & GDB_O_APPEND) hf |= O_APPEND;
  55     if (flags & GDB_O_CREAT) hf |= O_CREAT;
  56     if (flags & GDB_O_TRUNC) hf |= O_TRUNC;
  57     if (flags & GDB_O_EXCL) hf |= O_EXCL;
  58
  59     return hf;
  60 }
  61
  62 static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
  63 {
  64     struct gdb_stat *p;
  65
  66     p = lock_user(VERIFY_WRITE, addr, sizeof(struct gdb_stat), 0);
  67     if (!p) {
  68         /* FIXME - should this return an error code? */
  69         return;
  70     }
  71     p->gdb_st_dev = cpu_to_be32(s->st_dev);
  72     p->gdb_st_ino = cpu_to_be32(s->st_ino);
  73     p->gdb_st_mode = cpu_to_be32(s->st_mode);
  74     p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
  75     p->gdb_st_uid = cpu_to_be32(s->st_uid);
  76     p->gdb_st_gid = cpu_to_be32(s->st_gid);
  77     p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
  78     p->gdb_st_size = cpu_to_be64(s->st_size);
  79 #ifdef _WIN32
  80     /* Windows stat is missing some fields.  */
  81     p->gdb_st_blksize = 0;
  82     p->gdb_st_blocks = 0;
  83 #else
  84     p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
  85     p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
  86 #endif
  87     p->gdb_st_atime = cpu_to_be32(s->st_atime);
  88     p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
  89     p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
  90     unlock_user(p, addr, sizeof(struct gdb_stat));
  91 }
  92
  93 static void m68k_semi_u32_cb(CPUState *cs, uint64_t ret, int err)
  94 {
  95     M68kCPU *cpu = M68K_CPU(cs);
  96     CPUM68KState *env = &cpu->env;
  97
  98     target_ulong args = env->dregs[1];
  99     if (put_user_u32(ret, args) ||
 100         put_user_u32(err, args + 4)) {
 101         /*
 102          * The m68k semihosting ABI does not provide any way to report this
 103          * error to the guest, so the best we can do is log it in qemu.
 104          * It is always a guest error not to pass us a valid argument block.
 105          */
 106         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 107                       "discarded because argument block not writable\n");
 108     }
 109 }
 110
 111 static void m68k_semi_u64_cb(CPUState *cs, uint64_t ret, int err)
 112 {
 113     M68kCPU *cpu = M68K_CPU(cs);
 114     CPUM68KState *env = &cpu->env;
 115
 116     target_ulong args = env->dregs[1];
 117     if (put_user_u32(ret >> 32, args) ||
 118         put_user_u32(ret, args + 4) ||
 119         put_user_u32(err, args + 8)) {
 120         /* No way to report this via m68k semihosting ABI; just log it */
 121         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 122                       "discarded because argument block not writable\n");
 123     }
 124 }
 125
 126 /*
 127  * Read the input value from the argument block; fail the semihosting
 128  * call if the memory read fails.
 129  */
 130 #define GET_ARG(n) do {                                 \
 131     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 132         result = -1;                                    \
 133         errno = EFAULT;                                 \
 134         goto failed;                                    \
 135     }                                                   \
 136 } while (0)
 137
 138 void do_m68k_semihosting(CPUM68KState *env, int nr)
 139 {
 140     CPUState *cs = env_cpu(env);
 141     uint32_t args;
 142     target_ulong arg0, arg1, arg2, arg3;
 143     void *p;
 144     void *q;
 145     uint32_t len;
 146     uint32_t result;
 147
 148     args = env->dregs[1];
 149     switch (nr) {
 150     case HOSTED_EXIT:
 151         gdb_exit(env->dregs[0]);
 152         exit(env->dregs[0]);
 153     case HOSTED_OPEN:
 154         GET_ARG(0);
 155         GET_ARG(1);
 156         GET_ARG(2);
 157         GET_ARG(3);
 158         if (use_gdb_syscalls()) {
 159             gdb_do_syscall(m68k_semi_u32_cb, "open,%s,%x,%x", arg0, (int)arg1,
 160                            arg2, arg3);
 161             return;
 162         } else {
 163             p = lock_user_string(arg0);
 164             if (!p) {
 165                 /* FIXME - check error code? */
 166                 result = -1;
 167             } else {
 168                 result = open(p, translate_openflags(arg2), arg3);
 169                 unlock_user(p, arg0, 0);
 170             }
 171         }
 172         break;
 173     case HOSTED_CLOSE:
 174         {
 175             /* Ignore attempts to close stdin/out/err.  */
 176             GET_ARG(0);
 177             int fd = arg0;
 178             if (fd > 2) {
 179                 if (use_gdb_syscalls()) {
 180                     gdb_do_syscall(m68k_semi_u32_cb, "close,%x", arg0);
 181                     return;
 182                 } else {
 183                     result = close(fd);
 184                 }
 185             } else {
 186                 result = 0;
 187             }
 188             break;
 189         }
 190     case HOSTED_READ:
 191         GET_ARG(0);
 192         GET_ARG(1);
 193         GET_ARG(2);
 194         len = arg2;
 195         if (use_gdb_syscalls()) {
 196             gdb_do_syscall(m68k_semi_u32_cb, "read,%x,%x,%x",
 197                            arg0, arg1, len);
 198             return;
 199         } else {
 200             p = lock_user(VERIFY_WRITE, arg1, len, 0);
 201             if (!p) {
 202                 /* FIXME - check error code? */
 203                 result = -1;
 204             } else {
 205                 result = read(arg0, p, len);
 206                 unlock_user(p, arg1, len);
 207             }
 208         }
 209         break;
 210     case HOSTED_WRITE:
 211         GET_ARG(0);
 212         GET_ARG(1);
 213         GET_ARG(2);
 214         len = arg2;
 215         if (use_gdb_syscalls()) {
 216             gdb_do_syscall(m68k_semi_u32_cb, "write,%x,%x,%x",
 217                            arg0, arg1, len);
 218             return;
 219         } else {
 220             p = lock_user(VERIFY_READ, arg1, len, 1);
 221             if (!p) {
 222                 /* FIXME - check error code? */
 223                 result = -1;
 224             } else {
 225                 result = write(arg0, p, len);
 226                 unlock_user(p, arg0, 0);
 227             }
 228         }
 229         break;
 230     case HOSTED_LSEEK:
 231         {
 232             uint64_t off;
 233             GET_ARG(0);
 234             GET_ARG(1);
 235             GET_ARG(2);
 236             GET_ARG(3);
 237             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
 238             if (use_gdb_syscalls()) {
 239                 gdb_do_syscall(m68k_semi_u64_cb, "fseek,%x,%lx,%x",
 240                                arg0, off, arg3);
 241             } else {
 242                 off = lseek(arg0, off, arg3);
 243                 m68k_semi_u64_cb(cs, off, errno);
 244             }
 245             return;
 246         }
 247     case HOSTED_RENAME:
 248         GET_ARG(0);
 249         GET_ARG(1);
 250         GET_ARG(2);
 251         GET_ARG(3);
 252         if (use_gdb_syscalls()) {
 253             gdb_do_syscall(m68k_semi_u32_cb, "rename,%s,%s",
 254                            arg0, (int)arg1, arg2, (int)arg3);
 255             return;
 256         } else {
 257             p = lock_user_string(arg0);
 258             q = lock_user_string(arg2);
 259             if (!p || !q) {
 260                 /* FIXME - check error code? */
 261                 result = -1;
 262             } else {
 263                 result = rename(p, q);
 264             }
 265             unlock_user(p, arg0, 0);
 266             unlock_user(q, arg2, 0);
 267         }
 268         break;
 269     case HOSTED_UNLINK:
 270         GET_ARG(0);
 271         GET_ARG(1);
 272         if (use_gdb_syscalls()) {
 273             gdb_do_syscall(m68k_semi_u32_cb, "unlink,%s",
 274                            arg0, (int)arg1);
 275             return;
 276         } else {
 277             p = lock_user_string(arg0);
 278             if (!p) {
 279                 /* FIXME - check error code? */
 280                 result = -1;
 281             } else {
 282                 result = unlink(p);
 283                 unlock_user(p, arg0, 0);
 284             }
 285         }
 286         break;
 287     case HOSTED_STAT:
 288         GET_ARG(0);
 289         GET_ARG(1);
 290         GET_ARG(2);
 291         if (use_gdb_syscalls()) {
 292             gdb_do_syscall(m68k_semi_u32_cb, "stat,%s,%x",
 293                            arg0, (int)arg1, arg2);
 294             return;
 295         } else {
 296             struct stat s;
 297             p = lock_user_string(arg0);
 298             if (!p) {
 299                 /* FIXME - check error code? */
 300                 result = -1;
 301             } else {
 302                 result = stat(p, &s);
 303                 unlock_user(p, arg0, 0);
 304             }
 305             if (result == 0) {
 306                 translate_stat(env, arg2, &s);
 307             }
 308         }
 309         break;
 310     case HOSTED_FSTAT:
 311         GET_ARG(0);
 312         GET_ARG(1);
 313         if (use_gdb_syscalls()) {
 314             gdb_do_syscall(m68k_semi_u32_cb, "fstat,%x,%x",
 315                            arg0, arg1);
 316             return;
 317         } else {
 318             struct stat s;
 319             result = fstat(arg0, &s);
 320             if (result == 0) {
 321                 translate_stat(env, arg1, &s);
 322             }
 323         }
 324         break;
 325     case HOSTED_GETTIMEOFDAY:
 326         GET_ARG(0);
 327         GET_ARG(1);
 328         if (use_gdb_syscalls()) {
 329             gdb_do_syscall(m68k_semi_u32_cb, "gettimeofday,%x,%x",
 330                            arg0, arg1);
 331             return;
 332         } else {
 333             struct gdb_timeval *p;
 334             int64_t rt = g_get_real_time();
 335             p = lock_user(VERIFY_WRITE, arg0, sizeof(struct gdb_timeval), 0);
 336             if (!p) {
 337                 /* FIXME - check error code? */
 338                 result = -1;
 339             } else {
 340                 result = 0;
 341                 p->tv_sec = cpu_to_be32(rt / G_USEC_PER_SEC);
 342                 p->tv_usec = cpu_to_be64(rt % G_USEC_PER_SEC);
 343                 unlock_user(p, arg0, sizeof(struct gdb_timeval));
 344             }
 345         }
 346         break;
 347     case HOSTED_ISATTY:
 348         GET_ARG(0);
 349         if (use_gdb_syscalls()) {
 350             gdb_do_syscall(m68k_semi_u32_cb, "isatty,%x", arg0);
 351             return;
 352         } else {
 353             result = isatty(arg0);
 354         }
 355         break;
 356     case HOSTED_SYSTEM:
 357         GET_ARG(0);
 358         GET_ARG(1);
 359         if (use_gdb_syscalls()) {
 360             gdb_do_syscall(m68k_semi_u32_cb, "system,%s",
 361                            arg0, (int)arg1);
 362             return;
 363         } else {
 364             p = lock_user_string(arg0);
 365             if (!p) {
 366                 /* FIXME - check error code? */
 367                 result = -1;
 368             } else {
 369                 result = system(p);
 370                 unlock_user(p, arg0, 0);
 371             }
 372         }
 373         break;
 374     case HOSTED_INIT_SIM:
 375         /*
 376          * FIXME: This is wrong for boards where RAM does not start at
 377          * address zero.
 378          */
 379         env->dregs[1] = current_machine->ram_size;
 380         env->aregs[7] = current_machine->ram_size;
 381         return;
 382     default:
 383         cpu_abort(env_cpu(env), "Unsupported semihosting syscall %d\n", nr);
 384         result = 0;
 385     }
 386 failed:
 387     m68k_semi_u32_cb(cs, result, errno);
 388 }