ndisasm.c

   1 /* ndisasm.c   the Netwide Disassembler main module
   2  *
   3  * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
   4  * Julian Hall. All rights reserved. The software is
   5  * redistributable under the license given in the file "LICENSE"
   6  * distributed in the NASM archive.
   7  */
   8
   9 #include "compiler.h"
  10
  11 #include <stdio.h>
  12 #include <stdarg.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <ctype.h>
  16 #include <errno.h>
  17 #include <inttypes.h>
  18
  19 #include "insns.h"
  20 #include "nasm.h"
  21 #include "nasmlib.h"
  22 #include "sync.h"
  23 #include "disasm.h"
  24
  25 #define BPL 8                   /* bytes per line of hex dump */
  26
  27 static const char *help =
  28     "usage: ndisasm [-a] [-i] [-h] [-r] [-u] [-b bits] [-o origin] [-s sync...]\n"
  29     "               [-e bytes] [-k start,bytes] [-p vendor] file\n"
  30     "   -a or -i activates auto (intelligent) sync\n"
  31     "   -u same as -b 32\n"
  32     "   -b 16, -b 32 or -b 64 sets the processor mode\n"
  33     "   -h displays this text\n"
  34     "   -r or -v displays the version number\n"
  35     "   -e skips <bytes> bytes of header\n"
  36     "   -k avoids disassembling <bytes> bytes from position <start>\n"
  37     "   -p selects the preferred vendor instruction set (intel, amd, cyrix, idt)\n";
  38
  39 static void output_ins(uint32_t, uint8_t *, int, char *);
  40 static void skip(uint32_t dist, FILE * fp);
  41
  42 static void ndisasm_error(int severity, const char *fmt, ...)
  43 {
  44     va_list va;
  45
  46     va_start(va, fmt);
  47     vfprintf(stderr, fmt, va);
  48
  49     if (severity & ERR_FATAL)
  50         exit(1);
  51 }
  52
  53 int main(int argc, char **argv)
  54 {
  55     char buffer[INSN_MAX * 2], *p, *ep, *q;
  56     char outbuf[256];
  57     char *pname = *argv;
  58     char *filename = NULL;
  59     uint32_t nextsync, synclen, initskip = 0L;
  60     int lenread;
  61     int32_t lendis;
  62     bool autosync = false;
  63     int bits = 16, b;
  64     bool eof = false;
  65     uint32_t prefer = 0;
  66     bool rn_error;
  67     int32_t offset;
  68     FILE *fp;
  69
  70     nasm_set_malloc_error(ndisasm_error);
  71
  72     offset = 0;
  73     init_sync();
  74
  75     while (--argc) {
  76         char *v, *vv, *p = *++argv;
  77         if (*p == '-' && p[1]) {
  78             p++;
  79             while (*p)
  80                 switch (tolower(*p)) {
  81                 case 'a':      /* auto or intelligent sync */
  82                 case 'i':
  83                     autosync = true;
  84                     p++;
  85                     break;
  86                 case 'h':
  87                     fprintf(stderr, help);
  88                     return 0;
  89                 case 'r':
  90                 case 'v':
  91                     fprintf(stderr,
  92                             "NDISASM version %s compiled " __DATE__ "\n",
  93                             NASM_VER);
  94                     return 0;
  95                 case 'u':       /* -u for -b 32, -uu for -b 64 */
  96                     if (bits < 64)
  97                         bits <<= 1;
  98                     p++;
  99                     break;
 100                 case 'b':      /* bits */
 101                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 102                     if (!v) {
 103                         fprintf(stderr, "%s: `-b' requires an argument\n",
 104                                 pname);
 105                         return 1;
 106                     }
 107                     b = strtoul(v, &ep, 10);
 108                     if (*ep || !(bits == 16 || bits == 32 || bits == 64)) {
 109                         fprintf(stderr, "%s: argument to `-b' should"
 110                                 " be 16, 32 or 64\n", pname);
 111                     } else {
 112                         bits = b;
 113                     }
 114                     p = "";     /* force to next argument */
 115                     break;
 116                 case 'o':      /* origin */
 117                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 118                     if (!v) {
 119                         fprintf(stderr, "%s: `-o' requires an argument\n",
 120                                 pname);
 121                         return 1;
 122                     }
 123                     offset = readnum(v, &rn_error);
 124                     if (rn_error) {
 125                         fprintf(stderr,
 126                                 "%s: `-o' requires a numeric argument\n",
 127                                 pname);
 128                         return 1;
 129                     }
 130                     p = "";     /* force to next argument */
 131                     break;
 132                 case 's':      /* sync point */
 133                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 134                     if (!v) {
 135                         fprintf(stderr, "%s: `-s' requires an argument\n",
 136                                 pname);
 137                         return 1;
 138                     }
 139                     add_sync(readnum(v, &rn_error), 0L);
 140                     if (rn_error) {
 141                         fprintf(stderr,
 142                                 "%s: `-s' requires a numeric argument\n",
 143                                 pname);
 144                         return 1;
 145                     }
 146                     p = "";     /* force to next argument */
 147                     break;
 148                 case 'e':      /* skip a header */
 149                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 150                     if (!v) {
 151                         fprintf(stderr, "%s: `-e' requires an argument\n",
 152                                 pname);
 153                         return 1;
 154                     }
 155                     initskip = readnum(v, &rn_error);
 156                     if (rn_error) {
 157                         fprintf(stderr,
 158                                 "%s: `-e' requires a numeric argument\n",
 159                                 pname);
 160                         return 1;
 161                     }
 162                     p = "";     /* force to next argument */
 163                     break;
 164                 case 'k':      /* skip a region */
 165                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 166                     if (!v) {
 167                         fprintf(stderr, "%s: `-k' requires an argument\n",
 168                                 pname);
 169                         return 1;
 170                     }
 171                     vv = strchr(v, ',');
 172                     if (!vv) {
 173                         fprintf(stderr,
 174                                 "%s: `-k' requires two numbers separated"
 175                                 " by a comma\n", pname);
 176                         return 1;
 177                     }
 178                     *vv++ = '\0';
 179                     nextsync = readnum(v, &rn_error);
 180                     if (rn_error) {
 181                         fprintf(stderr,
 182                                 "%s: `-k' requires numeric arguments\n",
 183                                 pname);
 184                         return 1;
 185                     }
 186                     synclen = readnum(vv, &rn_error);
 187                     if (rn_error) {
 188                         fprintf(stderr,
 189                                 "%s: `-k' requires numeric arguments\n",
 190                                 pname);
 191                         return 1;
 192                     }
 193                     add_sync(nextsync, synclen);
 194                     p = "";     /* force to next argument */
 195                     break;
 196                 case 'p':      /* preferred vendor */
 197                     v = p[1] ? p + 1 : --argc ? *++argv : NULL;
 198                     if (!v) {
 199                         fprintf(stderr, "%s: `-p' requires an argument\n",
 200                                 pname);
 201                         return 1;
 202                     }
 203                     if (!strcmp(v, "intel")) {
 204                         prefer = 0;     /* Default */
 205                     } else if (!strcmp(v, "amd")) {
 206                         prefer = IF_AMD | IF_3DNOW;
 207                     } else if (!strcmp(v, "cyrix")) {
 208                         prefer = IF_CYRIX | IF_3DNOW;
 209                     } else if (!strcmp(v, "idt") || !strcmp(v, "centaur")
 210                                || !strcmp(v, "winchip")) {
 211                         prefer = IF_3DNOW;
 212                     } else {
 213                         fprintf(stderr,
 214                                 "%s: unknown vendor `%s' specified with `-p'\n",
 215                                 pname, v);
 216                         return 1;
 217                     }
 218                     p = "";     /* force to next argument */
 219                     break;
 220                 default:       /*bf */
 221                     fprintf(stderr, "%s: unrecognised option `-%c'\n",
 222                             pname, *p);
 223                     return 1;
 224                 }
 225         } else if (!filename) {
 226             filename = p;
 227         } else {
 228             fprintf(stderr, "%s: more than one filename specified\n",
 229                     pname);
 230             return 1;
 231         }
 232     }
 233
 234     if (!filename) {
 235         fprintf(stderr, help, pname);
 236         return 0;
 237     }
 238
 239     if (strcmp(filename, "-")) {
 240         fp = fopen(filename, "rb");
 241         if (!fp) {
 242             fprintf(stderr, "%s: unable to open `%s': %s\n",
 243                     pname, filename, strerror(errno));
 244             return 1;
 245         }
 246     } else
 247         fp = stdin;
 248
 249     if (initskip > 0)
 250         skip(initskip, fp);
 251
 252     /*
 253      * This main loop is really horrible, and wants rewriting with
 254      * an axe. It'll stay the way it is for a while though, until I
 255      * find the energy...
 256      */
 257
 258     p = q = buffer;
 259     nextsync = next_sync(offset, &synclen);
 260     do {
 261         uint32_t to_read = buffer + sizeof(buffer) - p;
 262         if ((nextsync || synclen) &&
 263             to_read > nextsync - offset - (p - q))
 264             to_read = nextsync - offset - (p - q);
 265         if (to_read) {
 266             lenread = fread(p, 1, to_read, fp);
 267             if (lenread == 0)
 268                 eof = true;     /* help along systems with bad feof */
 269         } else
 270             lenread = 0;
 271         p += lenread;
 272         if ((nextsync || synclen) &&
 273             (uint32_t)offset == nextsync) {
 274             if (synclen) {
 275                 fprintf(stdout, "%08"PRIX32"  skipping 0x%"PRIX32" bytes\n", offset, synclen);
 276                 offset += synclen;
 277                 skip(synclen, fp);
 278             }
 279             p = q = buffer;
 280             nextsync = next_sync(offset, &synclen);
 281         }
 282         while (p > q && (p - q >= INSN_MAX || lenread == 0)) {
 283             lendis =
 284                 disasm((uint8_t *) q, outbuf, sizeof(outbuf), bits, offset, autosync,
 285                        prefer);
 286             if (!lendis || lendis > (p - q)
 287                 || ((nextsync || synclen) &&
 288                     (uint32_t)lendis > nextsync - offset))
 289                 lendis = eatbyte((uint8_t *) q, outbuf, sizeof(outbuf));
 290             output_ins(offset, (uint8_t *) q, lendis, outbuf);
 291             q += lendis;
 292             offset += lendis;
 293         }
 294         if (q >= buffer + INSN_MAX) {
 295             uint8_t *r = (uint8_t *) buffer, *s = (uint8_t *) q;
 296             int count = p - q;
 297             while (count--)
 298                 *r++ = *s++;
 299             p -= (q - buffer);
 300             q = buffer;
 301         }
 302     } while (lenread > 0 || !(eof || feof(fp)));
 303
 304     if (fp != stdin)
 305         fclose(fp);
 306
 307     return 0;
 308 }
 309
 310 static void output_ins(uint32_t offset, uint8_t *data,
 311                        int datalen, char *insn)
 312 {
 313     int bytes;
 314     fprintf(stdout, "%08"PRIX32"  ", offset);
 315
 316     bytes = 0;
 317     while (datalen > 0 && bytes < BPL) {
 318         fprintf(stdout, "%02X", *data++);
 319         bytes++;
 320         datalen--;
 321     }
 322
 323     fprintf(stdout, "%*s%s\n", (BPL + 1 - bytes) * 2, "", insn);
 324
 325     while (datalen > 0) {
 326         fprintf(stdout, "         -");
 327         bytes = 0;
 328         while (datalen > 0 && bytes < BPL) {
 329             fprintf(stdout, "%02X", *data++);
 330             bytes++;
 331             datalen--;
 332         }
 333         fprintf(stdout, "\n");
 334     }
 335 }
 336
 337 /*
 338  * Skip a certain amount of data in a file, either by seeking if
 339  * possible, or if that fails then by reading and discarding.
 340  */
 341 static void skip(uint32_t dist, FILE * fp)
 342 {
 343     char buffer[256];           /* should fit on most stacks :-) */
 344
 345     /*
 346      * Got to be careful with fseek: at least one fseek I've tried
 347      * doesn't approve of SEEK_CUR. So I'll use SEEK_SET and
 348      * ftell... horrible but apparently necessary.
 349      */
 350     if (fseek(fp, dist + ftell(fp), SEEK_SET)) {
 351         while (dist > 0) {
 352             uint32_t len = (dist < sizeof(buffer) ?
 353                                  dist : sizeof(buffer));
 354             if (fread(buffer, 1, len, fp) < len) {
 355                 perror("fread");
 356                 exit(1);
 357             }
 358             dist -= len;
 359         }
 360     }
 361 }