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