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