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nasm/ndisasm.c
H. Peter Anvin 090a218573 NASM 0.98.17
2002-04-30 21:04:18 +00:00

321 lines
8.2 KiB
C
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/* ndisasm.c the Netwide Disassembler main module
*
* The Netwide Assembler is copyright (C) 1996 Simon Tatham and
* Julian Hall. All rights reserved. The software is
* redistributable under the licence given in the file "Licence"
* distributed in the NASM archive.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include "insns.h"
#include "nasm.h"
#include "nasmlib.h"
#include "sync.h"
#include "disasm.h"
#define BPL 8 /* bytes per line of hex dump */
static const char *help =
"usage: ndisasm [-a] [-i] [-h] [-r] [-u] [-b bits] [-o origin] [-s sync...]\n"
" [-e bytes] [-k start,bytes] [-p vendor] file\n"
" -a or -i activates auto (intelligent) sync\n"
" -u sets USE32 (32-bit mode)\n"
" -b 16 or -b 32 sets number of bits too\n"
" -h displays this text\n"
" -r or -v displays the version number\n"
" -e skips <bytes> bytes of header\n"
" -k avoids disassembling <bytes> bytes from position <start>\n"
" -p selects the preferred vendor instruction set (intel, amd, cyrix, idt)\n";
static void output_ins (unsigned long, unsigned char *, int, char *);
static void skip (unsigned long dist, FILE *fp);
int main(int argc, char **argv)
{
unsigned char buffer[INSN_MAX * 2], *p, *q;
char outbuf[256];
char *pname = *argv;
char *filename = NULL;
unsigned long nextsync, synclen, initskip = 0L;
int lenread;
long lendis;
int autosync = FALSE;
int bits = 16;
int eof = FALSE;
unsigned long prefer = 0;
int rn_error;
long offset;
FILE *fp;
offset = 0;
init_sync();
while (--argc) {
char *v, *vv, *p = *++argv;
if (*p == '-' && p[1]) {
p++;
while (*p) switch (tolower(*p)) {
case 'a': /* auto or intelligent sync */
case 'i':
autosync = TRUE;
p++;
break;
case 'h':
fprintf(stderr, help);
return 0;
case 'r':
case 'v':
fprintf(stderr, "NDISASM version %s compiled " __DATE__ "\n", NASM_VER);
return 0;
case 'u': /* USE32 */
bits = 32;
p++;
break;
case 'b': /* bits */
v = p[1] ? p+1 : --argc ? *++argv : NULL;
if (!v) {
fprintf(stderr, "%s: `-b' requires an argument\n", pname);
return 1;
}
if (!strcmp(v, "16"))
bits = 16;
else if (!strcmp(v, "32"))
bits = 32;
else {
fprintf(stderr, "%s: argument to `-b' should"
" be `16' or `32'\n", pname);
}
p = ""; /* force to next argument */
break;
case 'o': /* origin */
v = p[1] ? p+1 : --argc ? *++argv : NULL;
if (!v) {
fprintf(stderr, "%s: `-o' requires an argument\n", pname);
return 1;
}
offset = readnum (v, &rn_error);
if (rn_error) {
fprintf(stderr, "%s: `-o' requires a numeric argument\n",
pname);
return 1;
}
p = ""; /* force to next argument */
break;
case 's': /* sync point */
v = p[1] ? p+1 : --argc ? *++argv : NULL;
if (!v) {
fprintf(stderr, "%s: `-s' requires an argument\n", pname);
return 1;
}
add_sync (readnum (v, &rn_error), 0L);
if (rn_error) {
fprintf(stderr, "%s: `-s' requires a numeric argument\n",
pname);
return 1;
}
p = ""; /* force to next argument */
break;
case 'e': /* skip a header */
v = p[1] ? p+1 : --argc ? *++argv : NULL;
if (!v) {
fprintf(stderr, "%s: `-e' requires an argument\n", pname);
return 1;
}
initskip = readnum (v, &rn_error);
if (rn_error) {
fprintf(stderr, "%s: `-e' requires a numeric argument\n",
pname);
return 1;
}
p = ""; /* force to next argument */
break;
case 'k': /* skip a region */
v = p[1] ? p+1 : --argc ? *++argv : NULL;
if (!v) {
fprintf(stderr, "%s: `-k' requires an argument\n", pname);
return 1;
}
vv = strchr(v, ',');
if (!vv) {
fprintf(stderr, "%s: `-k' requires two numbers separated"
" by a comma\n", pname);
return 1;
}
*vv++ = '\0';
nextsync = readnum (v, &rn_error);
if (rn_error) {
fprintf(stderr, "%s: `-k' requires numeric arguments\n",
pname);
return 1;
}
synclen = readnum (vv, &rn_error);
if (rn_error) {
fprintf(stderr, "%s: `-k' requires numeric arguments\n",
pname);
return 1;
}
add_sync (nextsync, synclen);
p = ""; /* force to next argument */
break;
case 'p': /* preferred vendor */
v = p[1] ? p+1 : --argc ? *++argv : NULL;
if (!v) {
fprintf(stderr, "%s: `-p' requires an argument\n", pname);
return 1;
}
if ( !strcmp(v, "intel") ) {
prefer = 0; /* Default */
} else if ( !strcmp(v, "amd") ) {
prefer = IF_AMD|IF_3DNOW;
} else if ( !strcmp(v, "cyrix") ) {
prefer = IF_CYRIX|IF_3DNOW;
} else if ( !strcmp(v, "idt") || !strcmp(v, "centaur") ||
!strcmp(v, "winchip") ) {
prefer = IF_3DNOW;
} else {
fprintf(stderr, "%s: unknown vendor `%s' specified with `-p'\n", pname, v);
return 1;
}
p = ""; /* force to next argument */
break;
default: /*bf*/
fprintf(stderr, "%s: unrecognised option `-%c'\n",
pname, *p);
return 1;
}
} else if (!filename) {
filename = p;
} else {
fprintf(stderr, "%s: more than one filename specified\n", pname);
return 1;
}
}
if (!filename) {
fprintf(stderr, help, pname);
return 0;
}
if (strcmp(filename, "-")) {
fp = fopen(filename, "rb");
if (!fp) {
fprintf(stderr, "%s: unable to open `%s': %s\n",
pname, filename, strerror(errno));
return 1;
}
} else
fp = stdin;
if (initskip > 0)
skip (initskip, fp);
/*
* This main loop is really horrible, and wants rewriting with
* an axe. It'll stay the way it is for a while though, until I
* find the energy...
*/
p = q = buffer;
nextsync = next_sync (offset, &synclen);
do {
unsigned long to_read = buffer+sizeof(buffer)-p;
if (to_read > nextsync-offset-(p-q))
to_read = nextsync-offset-(p-q);
if (to_read) {
lenread = fread (p, 1, to_read, fp);
if (lenread == 0)
eof = TRUE; /* help along systems with bad feof */
} else
lenread = 0;
p += lenread;
if ((unsigned long)offset == nextsync) {
if (synclen) {
fprintf(stdout, "%08lX skipping 0x%lX bytes\n", offset, synclen);
offset += synclen;
skip (synclen, fp);
}
p = q = buffer;
nextsync = next_sync (offset, &synclen);
}
while (p > q && (p - q >= INSN_MAX || lenread == 0)) {
lendis = disasm (q, outbuf, bits, offset, autosync, prefer);
if (!lendis || lendis > (p - q) ||
(unsigned long)lendis > nextsync-offset)
lendis = eatbyte (q, outbuf);
output_ins (offset, q, lendis, outbuf);
q += lendis;
offset += lendis;
}
if (q >= buffer+INSN_MAX) {
unsigned char *r = buffer, *s = q;
int count = p - q;
while (count--)
*r++ = *s++;
p -= (q - buffer);
q = buffer;
}
} while (lenread > 0 || !(eof || feof(fp)));
if (fp != stdin)
fclose (fp);
return 0;
}
static void output_ins (unsigned long offset, unsigned char *data,
int datalen, char *insn)
{
int bytes;
fprintf(stdout, "%08lX ", offset);
bytes = 0;
while (datalen > 0 && bytes < BPL) {
fprintf(stdout, "%02X", *data++);
bytes++;
datalen--;
}
fprintf(stdout, "%*s%s\n", (BPL+1-bytes)*2, "", insn);
while (datalen > 0) {
fprintf(stdout, " -");
bytes = 0;
while (datalen > 0 && bytes < BPL) {
fprintf(stdout, "%02X", *data++);
bytes++;
datalen--;
}
fprintf(stdout, "\n");
}
}
/*
* Skip a certain amount of data in a file, either by seeking if
* possible, or if that fails then by reading and discarding.
*/
static void skip (unsigned long dist, FILE *fp)
{
char buffer[256]; /* should fit on most stacks :-) */
/*
* Got to be careful with fseek: at least one fseek I've tried
* doesn't approve of SEEK_CUR. So I'll use SEEK_SET and
* ftell... horrible but apparently necessary.
*/
if (fseek (fp, dist+ftell(fp), SEEK_SET)) {
while (dist > 0) {
unsigned long len = (dist < sizeof(buffer) ?
dist : sizeof(buffer));
if (fread (buffer, 1, len, fp) < len) {
perror("fread");
exit(1);
}
dist -= len;
}
}
}
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