ndisasm.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1996-2009 The NASM Authors - All Rights Reserved
   4  *   See the file AUTHORS included with the NASM distribution for
   5  *   the specific copyright holders.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following
   9  *   conditions are met:
  10  *
  11  *   * Redistributions of source code must retain the above copyright
  12  *     notice, this list of conditions and the following disclaimer.
  13  *   * Redistributions in binary form must reproduce the above
  14  *     copyright notice, this list of conditions and the following
  15  *     disclaimer in the documentation and/or other materials provided
  16  *     with the distribution.
  17  *
  18  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  19  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  21  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  29  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  30  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * ----------------------------------------------------------------------- */
  33
  34 /*
  35  * ndisasm.c   the Netwide Disassembler main module
  36  */
  37
  38 #include "compiler.h"
  39
  40 #include <stdio.h>
  41 #include <stdarg.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <inttypes.h>
  47
  48 #include "insns.h"
  49 #include "nasm.h"
  50 #include "nasmlib.h"
  51 #include "sync.h"
  52 #include "disasm.h"
  53
  54 #define BPL 8                   /* bytes per line of hex dump */
  55
  56 static const char *help =
  57     "usage: ndisasm [-a] [-i] [-h] [-r] [-u] [-b bits] [-o origin] [-s sync...]\n"
  58     "               [-e bytes] [-k start,bytes] [-p vendor] file\n"
  59     "   -a or -i activates auto (intelligent) sync\n"
  60     "   -u same as -b 32\n"
  61     "   -b 16, -b 32 or -b 64 sets the processor mode\n"
  62     "   -h displays this text\n"
  63     "   -r or -v displays the version number\n"
  64     "   -e skips <bytes> bytes of header\n"
  65     "   -k avoids disassembling <bytes> bytes from position <start>\n"
  66     "   -p selects the preferred vendor instruction set (intel, amd, cyrix, idt)\n";
  67
  68 static void output_ins(uint32_t, uint8_t *, int, char *);
  69 static void skip(uint32_t dist, FILE * fp);
  70
  71 static void ndisasm_verror(int severity, const char *fmt, va_list va)
  72 {
  73     vfprintf(stderr, fmt, va);
  74
  75     if (severity & ERR_FATAL)
  76         exit(1);
  77 }
  78
  79 int main(int argc, char **argv)
  80 {
  81     char buffer[INSN_MAX * 2], *p, *ep, *q;
  82     char outbuf[256];
  83     char *pname = *argv;
  84     char *filename = NULL;
  85     uint32_t nextsync, synclen, initskip = 0L;
  86     int lenread;
  87     int32_t lendis;
  88     bool autosync = false;
  89     int bits = 16, b;
  90     bool eof = false;
  91     iflag_t prefer;
  92     bool rn_error;
  93     int32_t offset;
  94     FILE *fp;
  95
  96     tolower_init();
  97     nasm_set_verror(ndisasm_verror);
  98     iflag_clear_all(&prefer);
  99
 100     offset = 0;
 101     init_sync();
 102
 103     while (--argc) {
 104         char *v, *vv, *p = *++argv;
 105         if (*p == '-' && p[1]) {
 106             p++;
 107             while (*p)
 108                 switch (nasm_tolower(*p)) {
 109                 case 'a':      /* auto or intelligent sync */
 110                 case 'i':
 111                     autosync = true;
 112                     p++;
 113                     break;
 114                 case 'h':
 115                     fputs(help, stderr);
 116                     return 0;
 117                 case 'r':
 118                 case 'v':
 119                     fprintf(stderr,
 120                             "NDISASM version %s compiled on %s\n",
 121                             nasm_version, nasm_date);
 122                     return 0;
 123                 case 'u':       /* -u for -b 32, -uu for -b 64 */
 124                     if (bits < 64)
 125                         bits <<= 1;
 126                     p++;
 127                     break;
 128                 case 'b':      /* bits */
 129                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 130                     if (!v) {
 131                         fprintf(stderr, "%s: `-b' requires an argument\n",
 132                                 pname);
 133                         return 1;
 134                     }
 135                     b = strtoul(v, &ep, 10);
 136                     if (*ep || !(bits == 16 || bits == 32 || bits == 64)) {
 137                         fprintf(stderr, "%s: argument to `-b' should"
 138                                 " be 16, 32 or 64\n", pname);
 139                     } else {
 140                         bits = b;
 141                     }
 142                     p = "";     /* force to next argument */
 143                     break;
 144                 case 'o':      /* origin */
 145                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 146                     if (!v) {
 147                         fprintf(stderr, "%s: `-o' requires an argument\n",
 148                                 pname);
 149                         return 1;
 150                     }
 151                     offset = readnum(v, &rn_error);
 152                     if (rn_error) {
 153                         fprintf(stderr,
 154                                 "%s: `-o' requires a numeric argument\n",
 155                                 pname);
 156                         return 1;
 157                     }
 158                     p = "";     /* force to next argument */
 159                     break;
 160                 case 's':      /* sync point */
 161                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 162                     if (!v) {
 163                         fprintf(stderr, "%s: `-s' requires an argument\n",
 164                                 pname);
 165                         return 1;
 166                     }
 167                     add_sync(readnum(v, &rn_error), 0L);
 168                     if (rn_error) {
 169                         fprintf(stderr,
 170                                 "%s: `-s' requires a numeric argument\n",
 171                                 pname);
 172                         return 1;
 173                     }
 174                     p = "";     /* force to next argument */
 175                     break;
 176                 case 'e':      /* skip a header */
 177                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 178                     if (!v) {
 179                         fprintf(stderr, "%s: `-e' requires an argument\n",
 180                                 pname);
 181                         return 1;
 182                     }
 183                     initskip = readnum(v, &rn_error);
 184                     if (rn_error) {
 185                         fprintf(stderr,
 186                                 "%s: `-e' requires a numeric argument\n",
 187                                 pname);
 188                         return 1;
 189                     }
 190                     p = "";     /* force to next argument */
 191                     break;
 192                 case 'k':      /* skip a region */
 193                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 194                     if (!v) {
 195                         fprintf(stderr, "%s: `-k' requires an argument\n",
 196                                 pname);
 197                         return 1;
 198                     }
 199                     vv = strchr(v, ',');
 200                     if (!vv) {
 201                         fprintf(stderr,
 202                                 "%s: `-k' requires two numbers separated"
 203                                 " by a comma\n", pname);
 204                         return 1;
 205                     }
 206                     *vv++ = '\0';
 207                     nextsync = readnum(v, &rn_error);
 208                     if (rn_error) {
 209                         fprintf(stderr,
 210                                 "%s: `-k' requires numeric arguments\n",
 211                                 pname);
 212                         return 1;
 213                     }
 214                     synclen = readnum(vv, &rn_error);
 215                     if (rn_error) {
 216                         fprintf(stderr,
 217                                 "%s: `-k' requires numeric arguments\n",
 218                                 pname);
 219                         return 1;
 220                     }
 221                     add_sync(nextsync, synclen);
 222                     p = "";     /* force to next argument */
 223                     break;
 224                 case 'p':      /* preferred vendor */
 225                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 226                     if (!v) {
 227                         fprintf(stderr, "%s: `-p' requires an argument\n",
 228                                 pname);
 229                         return 1;
 230                     }
 231                     if (!strcmp(v, "intel")) {
 232                         iflag_clear_all(&prefer); /* default */
 233                     } else if (!strcmp(v, "amd")) {
 234                         iflag_clear_all(&prefer);
 235                         iflag_set(&prefer, IF_AMD);
 236                         iflag_set(&prefer, IF_3DNOW);
 237                     } else if (!strcmp(v, "cyrix")) {
 238                         iflag_clear_all(&prefer);
 239                         iflag_set(&prefer, IF_CYRIX);
 240                         iflag_set(&prefer, IF_3DNOW);
 241                     } else if (!strcmp(v, "idt") ||
 242                                !strcmp(v, "centaur") ||
 243                                !strcmp(v, "winchip")) {
 244                         iflag_clear_all(&prefer);
 245                         iflag_set(&prefer, IF_3DNOW);
 246                     } else {
 247                         fprintf(stderr,
 248                                 "%s: unknown vendor `%s' specified with `-p'\n",
 249                                 pname, v);
 250                         return 1;
 251                     }
 252                     p = "";     /* force to next argument */
 253                     break;
 254                 default:       /*bf */
 255                     fprintf(stderr, "%s: unrecognised option `-%c'\n",
 256                             pname, *p);
 257                     return 1;
 258                 }
 259         } else if (!filename) {
 260             filename = p;
 261         } else {
 262             fprintf(stderr, "%s: more than one filename specified\n",
 263                     pname);
 264             return 1;
 265         }
 266     }
 267
 268     if (!filename) {
 269         fprintf(stderr, help, pname);
 270         return 0;
 271     }
 272
 273     if (strcmp(filename, "-")) {
 274         fp = fopen(filename, "rb");
 275         if (!fp) {
 276             fprintf(stderr, "%s: unable to open `%s': %s\n",
 277                     pname, filename, strerror(errno));
 278             return 1;
 279         }
 280     } else
 281         fp = stdin;
 282
 283     if (initskip > 0)
 284         skip(initskip, fp);
 285
 286     /*
 287      * This main loop is really horrible, and wants rewriting with
 288      * an axe. It'll stay the way it is for a while though, until I
 289      * find the energy...
 290      */
 291
 292     p = q = buffer;
 293     nextsync = next_sync(offset, &synclen);
 294     do {
 295         uint32_t to_read = buffer + sizeof(buffer) - p;
 296         if ((nextsync || synclen) &&
 297             to_read > nextsync - offset - (p - q))
 298             to_read = nextsync - offset - (p - q);
 299         if (to_read) {
 300             lenread = fread(p, 1, to_read, fp);
 301             if (lenread == 0)
 302                 eof = true;     /* help along systems with bad feof */
 303         } else
 304             lenread = 0;
 305         p += lenread;
 306         if ((nextsync || synclen) &&
 307             (uint32_t)offset == nextsync) {
 308             if (synclen) {
 309                 fprintf(stdout, "%08"PRIX32"  skipping 0x%"PRIX32" bytes\n",
 310                         offset, synclen);
 311                 offset += synclen;
 312                 skip(synclen, fp);
 313             }
 314             p = q = buffer;
 315             nextsync = next_sync(offset, &synclen);
 316         }
 317         while (p > q && (p - q >= INSN_MAX || lenread == 0)) {
 318             lendis =
 319                 disasm((uint8_t *) q, outbuf, sizeof(outbuf), bits,
 320                        offset, autosync, &prefer);
 321             if (!lendis || lendis > (p - q)
 322                 || ((nextsync || synclen) &&
 323                     (uint32_t)lendis > nextsync - offset))
 324                 lendis = eatbyte((uint8_t *) q, outbuf, sizeof(outbuf), bits);
 325             output_ins(offset, (uint8_t *) q, lendis, outbuf);
 326             q += lendis;
 327             offset += lendis;
 328         }
 329         if (q >= buffer + INSN_MAX) {
 330             uint8_t *r = (uint8_t *) buffer, *s = (uint8_t *) q;
 331             int count = p - q;
 332             while (count--)
 333                 *r++ = *s++;
 334             p -= (q - buffer);
 335             q = buffer;
 336         }
 337     } while (lenread > 0 || !(eof || feof(fp)));
 338
 339     if (fp != stdin)
 340         fclose(fp);
 341
 342     return 0;
 343 }
 344
 345 static void output_ins(uint32_t offset, uint8_t *data,
 346                        int datalen, char *insn)
 347 {
 348     int bytes;
 349     fprintf(stdout, "%08"PRIX32"  ", offset);
 350
 351     bytes = 0;
 352     while (datalen > 0 && bytes < BPL) {
 353         fprintf(stdout, "%02X", *data++);
 354         bytes++;
 355         datalen--;
 356     }
 357
 358     fprintf(stdout, "%*s%s\n", (BPL + 1 - bytes) * 2, "", insn);
 359
 360     while (datalen > 0) {
 361         fprintf(stdout, "         -");
 362         bytes = 0;
 363         while (datalen > 0 && bytes < BPL) {
 364             fprintf(stdout, "%02X", *data++);
 365             bytes++;
 366             datalen--;
 367         }
 368         fprintf(stdout, "\n");
 369     }
 370 }
 371
 372 /*
 373  * Skip a certain amount of data in a file, either by seeking if
 374  * possible, or if that fails then by reading and discarding.
 375  */
 376 static void skip(uint32_t dist, FILE * fp)
 377 {
 378     char buffer[256];           /* should fit on most stacks :-) */
 379
 380     /*
 381      * Got to be careful with fseek: at least one fseek I've tried
 382      * doesn't approve of SEEK_CUR. So I'll use SEEK_SET and
 383      * ftell... horrible but apparently necessary.
 384      */
 385     if (fseek(fp, dist + ftell(fp), SEEK_SET)) {
 386         while (dist > 0) {
 387             uint32_t len = (dist < sizeof(buffer) ?
 388                                  dist : sizeof(buffer));
 389             if (fread(buffer, 1, len, fp) < len) {
 390                 perror("fread");
 391                 exit(1);
 392             }
 393             dist -= len;
 394         }
 395     }
 396 }