1 /* ndisasm.c the Netwide Disassembler main module
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.
21 #define BPL 8 /* bytes per line of hex dump */
23 static const char *help =
24 "usage: ndisasm [-a] [-i] [-h] [-r] [-u] [-b bits] [-o origin] [-s sync...]\n"
25 " [-e bytes] [-k start,bytes] [-p vendor] file\n"
26 " -a or -i activates auto (intelligent) sync\n"
27 " -u sets USE32 (32-bit mode)\n"
28 " -b 16 or -b 32 sets number of bits too\n"
29 " -h displays this text\n"
30 " -r displays the version number\n"
31 " -e skips <bytes> bytes of header\n"
32 " -k avoids disassembling <bytes> bytes from position <start>\n"
33 " -p selects the preferred vendor instruction set (intel, amd, cyrix)\n";
35 static void output_ins (unsigned long, unsigned char *, int, char *);
36 static void skip (unsigned long dist, FILE *fp);
38 int main(int argc, char **argv)
40 unsigned char buffer[INSN_MAX * 2], *p, *q;
43 char *filename = NULL;
44 unsigned long nextsync, synclen, initskip = 0L;
49 unsigned long prefer = 0;
58 char *v, *vv, *p = *++argv;
59 if (*p == '-' && p[1]) {
61 while (*p) switch (tolower(*p)) {
62 case 'a': /* auto or intelligent sync */
68 fprintf(stderr, help);
71 fprintf(stderr, "NDISASM version " NASM_VER "\n");
78 v = p[1] ? p+1 : --argc ? *++argv : NULL;
80 fprintf(stderr, "%s: `-b' requires an argument\n", pname);
85 else if (!strcmp(v, "32"))
88 fprintf(stderr, "%s: argument to `-b' should"
89 " be `16' or `32'\n", pname);
91 p = ""; /* force to next argument */
93 case 'o': /* origin */
94 v = p[1] ? p+1 : --argc ? *++argv : NULL;
96 fprintf(stderr, "%s: `-o' requires an argument\n", pname);
99 offset = readnum (v, &rn_error);
101 fprintf(stderr, "%s: `-o' requires a numeric argument\n",
105 p = ""; /* force to next argument */
107 case 's': /* sync point */
108 v = p[1] ? p+1 : --argc ? *++argv : NULL;
110 fprintf(stderr, "%s: `-s' requires an argument\n", pname);
113 add_sync (readnum (v, &rn_error), 0L);
115 fprintf(stderr, "%s: `-s' requires a numeric argument\n",
119 p = ""; /* force to next argument */
121 case 'e': /* skip a header */
122 v = p[1] ? p+1 : --argc ? *++argv : NULL;
124 fprintf(stderr, "%s: `-e' requires an argument\n", pname);
127 initskip = readnum (v, &rn_error);
129 fprintf(stderr, "%s: `-e' requires a numeric argument\n",
133 p = ""; /* force to next argument */
135 case 'k': /* skip a region */
136 v = p[1] ? p+1 : --argc ? *++argv : NULL;
138 fprintf(stderr, "%s: `-k' requires an argument\n", pname);
143 fprintf(stderr, "%s: `-k' requires two numbers separated"
144 " by a comma\n", pname);
148 nextsync = readnum (v, &rn_error);
150 fprintf(stderr, "%s: `-k' requires numeric arguments\n",
154 synclen = readnum (vv, &rn_error);
156 fprintf(stderr, "%s: `-k' requires numeric arguments\n",
160 add_sync (nextsync, synclen);
161 p = ""; /* force to next argument */
163 case 'p': /* preferred vendor */
164 v = p[1] ? p+1 : --argc ? *++argv : NULL;
166 fprintf(stderr, "%s: `-p' requires an argument\n", pname);
169 if ( !strcmp(v, "intel") ) {
170 prefer = 0; /* Default */
171 } else if ( !strcmp(v, "amd") ) {
172 prefer = IF_AMD|IF_3DNOW;
173 } else if ( !strcmp(v, "cyrix") ) {
174 prefer = IF_CYRIX|IF_3DNOW;
176 fprintf(stderr, "%s: unknown vendor `%s' specified with `-p'\n", pname, v);
179 p = ""; /* force to next argument */
182 } else if (!filename) {
185 fprintf(stderr, "%s: more than one filename specified\n", pname);
191 fprintf(stderr, help, pname);
195 if (strcmp(filename, "-")) {
196 fp = fopen(filename, "rb");
198 fprintf(stderr, "%s: unable to open `%s': %s\n",
199 pname, filename, strerror(errno));
209 * This main loop is really horrible, and wants rewriting with
210 * an axe. It'll stay the way it is for a while though, until I
215 nextsync = next_sync (offset, &synclen);
217 unsigned long to_read = buffer+sizeof(buffer)-p;
218 if (to_read > nextsync-offset-(p-q))
219 to_read = nextsync-offset-(p-q);
221 lenread = fread (p, 1, to_read, fp);
223 eof = TRUE; /* help along systems with bad feof */
227 if (offset == nextsync) {
229 printf("%08lX skipping 0x%lX bytes\n", offset, synclen);
234 nextsync = next_sync (offset, &synclen);
236 while (p > q && (p - q >= INSN_MAX || lenread == 0)) {
237 lendis = disasm (q, outbuf, bits, offset, autosync, prefer);
238 if (!lendis || lendis > (p - q) ||
239 lendis > nextsync-offset)
240 lendis = eatbyte (q, outbuf);
241 output_ins (offset, q, lendis, outbuf);
245 if (q >= buffer+INSN_MAX) {
246 unsigned char *r = buffer, *s = q;
253 } while (lenread > 0 || !(eof || feof(fp)));
261 static void output_ins (unsigned long offset, unsigned char *data,
262 int datalen, char *insn)
265 printf("%08lX ", offset);
268 while (datalen > 0 && bytes < BPL) {
269 printf("%02X", *data++);
274 printf("%*s%s\n", (BPL+1-bytes)*2, "", insn);
276 while (datalen > 0) {
279 while (datalen > 0 && bytes < BPL) {
280 printf("%02X", *data++);
289 * Skip a certain amount of data in a file, either by seeking if
290 * possible, or if that fails then by reading and discarding.
292 static void skip (unsigned long dist, FILE *fp)
294 char buffer[256]; /* should fit on most stacks :-) */
297 * Got to be careful with fseek: at least one fseek I've tried
298 * doesn't approve of SEEK_CUR. So I'll use SEEK_SET and
299 * ftell... horrible but apparently necessary.
301 if (fseek (fp, dist+ftell(fp), SEEK_SET)) {
303 unsigned long len = (dist < sizeof(buffer) ?
304 dist : sizeof(buffer));
305 if (fread (buffer, 1, len, fp) < len) {