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_error(int severity, const char *fmt, ...)
  72 {
  73     va_list va;
  74
  75     va_start(va, fmt);
  76     vfprintf(stderr, fmt, va);
  77
  78     if (severity & ERR_FATAL)
  79         exit(1);
  80 }
  81
  82 int main(int argc, char **argv)
  83 {
  84     char buffer[INSN_MAX * 2], *p, *ep, *q;
  85     char outbuf[256];
  86     char *pname = *argv;
  87     char *filename = NULL;
  88     uint32_t nextsync, synclen, initskip = 0L;
  89     int lenread;
  90     int32_t lendis;
  91     bool autosync = false;
  92     int bits = 16, b;
  93     bool eof = false;
  94     uint32_t prefer = 0;
  95     bool rn_error;
  96     int32_t offset;
  97     FILE *fp;
  98
  99     tolower_init();
 100     nasm_set_malloc_error(ndisasm_error);
 101
 102     offset = 0;
 103     init_sync();
 104
 105     while (--argc) {
 106         char *v, *vv, *p = *++argv;
 107         if (*p == '-' && p[1]) {
 108             p++;
 109             while (*p)
 110                 switch (nasm_tolower(*p)) {
 111                 case 'a':      /* auto or intelligent sync */
 112                 case 'i':
 113                     autosync = true;
 114                     p++;
 115                     break;
 116                 case 'h':
 117                     fprintf(stderr, help);
 118                     return 0;
 119                 case 'r':
 120                 case 'v':
 121                     fprintf(stderr,
 122                             "NDISASM version %s compiled on %s\n",
 123                             nasm_version, nasm_date);
 124                     return 0;
 125                 case 'u':       /* -u for -b 32, -uu for -b 64 */
 126                     if (bits < 64)
 127                         bits <<= 1;
 128                     p++;
 129                     break;
 130                 case 'b':      /* bits */
 131                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 132                     if (!v) {
 133                         fprintf(stderr, "%s: `-b' requires an argument\n",
 134                                 pname);
 135                         return 1;
 136                     }
 137                     b = strtoul(v, &ep, 10);
 138                     if (*ep || !(bits == 16 || bits == 32 || bits == 64)) {
 139                         fprintf(stderr, "%s: argument to `-b' should"
 140                                 " be 16, 32 or 64\n", pname);
 141                     } else {
 142                         bits = b;
 143                     }
 144                     p = "";     /* force to next argument */
 145                     break;
 146                 case 'o':      /* origin */
 147                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 148                     if (!v) {
 149                         fprintf(stderr, "%s: `-o' requires an argument\n",
 150                                 pname);
 151                         return 1;
 152                     }
 153                     offset = readnum(v, &rn_error);
 154                     if (rn_error) {
 155                         fprintf(stderr,
 156                                 "%s: `-o' requires a numeric argument\n",
 157                                 pname);
 158                         return 1;
 159                     }
 160                     p = "";     /* force to next argument */
 161                     break;
 162                 case 's':      /* sync point */
 163                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 164                     if (!v) {
 165                         fprintf(stderr, "%s: `-s' requires an argument\n",
 166                                 pname);
 167                         return 1;
 168                     }
 169                     add_sync(readnum(v, &rn_error), 0L);
 170                     if (rn_error) {
 171                         fprintf(stderr,
 172                                 "%s: `-s' requires a numeric argument\n",
 173                                 pname);
 174                         return 1;
 175                     }
 176                     p = "";     /* force to next argument */
 177                     break;
 178                 case 'e':      /* skip a header */
 179                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 180                     if (!v) {
 181                         fprintf(stderr, "%s: `-e' requires an argument\n",
 182                                 pname);
 183                         return 1;
 184                     }
 185                     initskip = readnum(v, &rn_error);
 186                     if (rn_error) {
 187                         fprintf(stderr,
 188                                 "%s: `-e' requires a numeric argument\n",
 189                                 pname);
 190                         return 1;
 191                     }
 192                     p = "";     /* force to next argument */
 193                     break;
 194                 case 'k':      /* skip a region */
 195                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 196                     if (!v) {
 197                         fprintf(stderr, "%s: `-k' requires an argument\n",
 198                                 pname);
 199                         return 1;
 200                     }
 201                     vv = strchr(v, ',');
 202                     if (!vv) {
 203                         fprintf(stderr,
 204                                 "%s: `-k' requires two numbers separated"
 205                                 " by a comma\n", pname);
 206                         return 1;
 207                     }
 208                     *vv++ = '\0';
 209                     nextsync = readnum(v, &rn_error);
 210                     if (rn_error) {
 211                         fprintf(stderr,
 212                                 "%s: `-k' requires numeric arguments\n",
 213                                 pname);
 214                         return 1;
 215                     }
 216                     synclen = readnum(vv, &rn_error);
 217                     if (rn_error) {
 218                         fprintf(stderr,
 219                                 "%s: `-k' requires numeric arguments\n",
 220                                 pname);
 221                         return 1;
 222                     }
 223                     add_sync(nextsync, synclen);
 224                     p = "";     /* force to next argument */
 225                     break;
 226                 case 'p':      /* preferred vendor */
 227                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 228                     if (!v) {
 229                         fprintf(stderr, "%s: `-p' requires an argument\n",
 230                                 pname);
 231                         return 1;
 232                     }
 233                     if (!strcmp(v, "intel")) {
 234                         prefer = 0;     /* Default */
 235                     } else if (!strcmp(v, "amd")) {
 236                         prefer = IF_AMD | IF_3DNOW;
 237                     } else if (!strcmp(v, "cyrix")) {
 238                         prefer = IF_CYRIX | IF_3DNOW;
 239                     } else if (!strcmp(v, "idt") || !strcmp(v, "centaur")
 240                                || !strcmp(v, "winchip")) {
 241                         prefer = IF_3DNOW;
 242                     } else {
 243                         fprintf(stderr,
 244                                 "%s: unknown vendor `%s' specified with `-p'\n",
 245                                 pname, v);
 246                         return 1;
 247                     }
 248                     p = "";     /* force to next argument */
 249                     break;
 250                 default:       /*bf */
 251                     fprintf(stderr, "%s: unrecognised option `-%c'\n",
 252                             pname, *p);
 253                     return 1;
 254                 }
 255         } else if (!filename) {
 256             filename = p;
 257         } else {
 258             fprintf(stderr, "%s: more than one filename specified\n",
 259                     pname);
 260             return 1;
 261         }
 262     }
 263
 264     if (!filename) {
 265         fprintf(stderr, help, pname);
 266         return 0;
 267     }
 268
 269     if (strcmp(filename, "-")) {
 270         fp = fopen(filename, "rb");
 271         if (!fp) {
 272             fprintf(stderr, "%s: unable to open `%s': %s\n",
 273                     pname, filename, strerror(errno));
 274             return 1;
 275         }
 276     } else
 277         fp = stdin;
 278
 279     if (initskip > 0)
 280         skip(initskip, fp);
 281
 282     /*
 283      * This main loop is really horrible, and wants rewriting with
 284      * an axe. It'll stay the way it is for a while though, until I
 285      * find the energy...
 286      */
 287
 288     p = q = buffer;
 289     nextsync = next_sync(offset, &synclen);
 290     do {
 291         uint32_t to_read = buffer + sizeof(buffer) - p;
 292         if ((nextsync || synclen) &&
 293             to_read > nextsync - offset - (p - q))
 294             to_read = nextsync - offset - (p - q);
 295         if (to_read) {
 296             lenread = fread(p, 1, to_read, fp);
 297             if (lenread == 0)
 298                 eof = true;     /* help along systems with bad feof */
 299         } else
 300             lenread = 0;
 301         p += lenread;
 302         if ((nextsync || synclen) &&
 303             (uint32_t)offset == nextsync) {
 304             if (synclen) {
 305                 fprintf(stdout, "%08"PRIX32"  skipping 0x%"PRIX32" bytes\n",
 306                         offset, synclen);
 307                 offset += synclen;
 308                 skip(synclen, fp);
 309             }
 310             p = q = buffer;
 311             nextsync = next_sync(offset, &synclen);
 312         }
 313         while (p > q && (p - q >= INSN_MAX || lenread == 0)) {
 314             lendis =
 315                 disasm((uint8_t *) q, outbuf, sizeof(outbuf), bits,
 316                        offset, autosync, prefer);
 317             if (!lendis || lendis > (p - q)
 318                 || ((nextsync || synclen) &&
 319                     (uint32_t)lendis > nextsync - offset))
 320                 lendis = eatbyte((uint8_t *) q, outbuf, sizeof(outbuf), bits);
 321             output_ins(offset, (uint8_t *) q, lendis, outbuf);
 322             q += lendis;
 323             offset += lendis;
 324         }
 325         if (q >= buffer + INSN_MAX) {
 326             uint8_t *r = (uint8_t *) buffer, *s = (uint8_t *) q;
 327             int count = p - q;
 328             while (count--)
 329                 *r++ = *s++;
 330             p -= (q - buffer);
 331             q = buffer;
 332         }
 333     } while (lenread > 0 || !(eof || feof(fp)));
 334
 335     if (fp != stdin)
 336         fclose(fp);
 337
 338     return 0;
 339 }
 340
 341 static void output_ins(uint32_t offset, uint8_t *data,
 342                        int datalen, char *insn)
 343 {
 344     int bytes;
 345     fprintf(stdout, "%08"PRIX32"  ", offset);
 346
 347     bytes = 0;
 348     while (datalen > 0 && bytes < BPL) {
 349         fprintf(stdout, "%02X", *data++);
 350         bytes++;
 351         datalen--;
 352     }
 353
 354     fprintf(stdout, "%*s%s\n", (BPL + 1 - bytes) * 2, "", insn);
 355
 356     while (datalen > 0) {
 357         fprintf(stdout, "         -");
 358         bytes = 0;
 359         while (datalen > 0 && bytes < BPL) {
 360             fprintf(stdout, "%02X", *data++);
 361             bytes++;
 362             datalen--;
 363         }
 364         fprintf(stdout, "\n");
 365     }
 366 }
 367
 368 /*
 369  * Skip a certain amount of data in a file, either by seeking if
 370  * possible, or if that fails then by reading and discarding.
 371  */
 372 static void skip(uint32_t dist, FILE * fp)
 373 {
 374     char buffer[256];           /* should fit on most stacks :-) */
 375
 376     /*
 377      * Got to be careful with fseek: at least one fseek I've tried
 378      * doesn't approve of SEEK_CUR. So I'll use SEEK_SET and
 379      * ftell... horrible but apparently necessary.
 380      */
 381     if (fseek(fp, dist + ftell(fp), SEEK_SET)) {
 382         while (dist > 0) {
 383             uint32_t len = (dist < sizeof(buffer) ?
 384                                  dist : sizeof(buffer));
 385             if (fread(buffer, 1, len, fp) < len) {
 386                 perror("fread");
 387                 exit(1);
 388             }
 389             dist -= len;
 390         }
 391     }
 392 }