/*
 * This program parses an S-record file (TI's *.m0 or otherwise), identifies
 * the set of discontiguous regions into which this SREC image deposits bits,
 * and lists these identified regions.
 */

#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>

char *infname;
FILE *inf;
char srecbuf[1024];
u_char srecbin[256];
int lineno, state;
u_long region_start, region_end;

decode_hex_byte(s)
	char *s;
{
	register int u, l;

	if (!isxdigit(s[0]) || !isxdigit(s[1]))
		return(-1);
	if (isdigit(s[0]))
		u = s[0] - '0';
	else if (isupper(s[0]))
		u = s[0] - 'A' + 10;
	else
		u = s[0] - 'a' + 10;
	if (isdigit(s[1]))
		l = s[1] - '0';
	else if (isupper(s[1]))
		l = s[1] - 'A' + 10;
	else
		l = s[1] - 'a' + 10;
	return((u << 4) | l);
}

srec2bin()
{
	register int i, l, b;

	l = decode_hex_byte(srecbuf + 2);
	if (l < 1) {
		fprintf(stderr, "%s line %d: S-record length octet is bad\n",
			infname, lineno);
		exit(1);
	}
	srecbin[0] = l;
	for (i = 1; i <= l; i++) {
		b = decode_hex_byte(srecbuf + i*2 + 2);
		if (b < 0) {
			fprintf(stderr, "%s line %d: hex decode error\n",
				infname, lineno);
			exit(1);
		}
		srecbin[i] = b;
	}
	return(0);
}

srec_cksum()
{
	u_char accum;
	register int i, len;

	len = srecbin[0] + 1;
	accum = 0;
	for (i = 0; i < len; i++)
		accum += srecbin[i];
	if (accum != 0xFF) {
		fprintf(stderr, "%s line %d: bad checksum\n", infname, lineno);
		exit(1);
	}
	return(0);
}

main(argc, argv)
	char **argv;
{
	register int i;
	u_long curaddr;
	int datalen;

	if (argc != 2) {
		fprintf(stderr, "usage: %s image.m0\n", argv[0]);
		exit(1);
	}
	infname = argv[1];
	inf = fopen(infname, "r");
	if (!inf) {
		perror(infname);
		exit(1);
	}

	state = 0;
	for (lineno = 1; ; lineno++) {
		if (!fgets(srecbuf, sizeof srecbuf, inf)) {
			fprintf(stderr, "%s: premature EOF\n", infname);
			exit(1);
		}
		if (srecbuf[0] != 'S') {
			fprintf(stderr, "%s line %d: not an S-record\n",
				infname, lineno);
			exit(1);
		}
		switch (srecbuf[1]) {
		case '0':
			if (state == 0)
				break;
			else
				goto badtype;
		case '3':
			if (state == 0)
				goto badtype;
			else
				break;
		case '7':
			if (state == 2)
				break;
			else
				goto badtype;
		default:
		badtype:
			fprintf(stderr,
				"%s line %d: S-record type unexpected\n",
				infname, lineno);
			exit(1);
		}
		srec2bin();
		srec_cksum();
		switch (srecbuf[1]) {
		case '0':
			state = 1;
			continue;
		case '3':
			if (srecbin[0] < 6) {
				fprintf(stderr,
					"%s line %d: S3 record is too short\n",
					infname, lineno);
				exit(1);
			}
			curaddr = (srecbin[1] << 24) | (srecbin[2] << 16) |
				  (srecbin[3] << 8) | srecbin[4];
			datalen = srecbin[0] - 5;
			if (state < 2) {
				region_start = curaddr;
				region_end = curaddr + datalen;
				state = 2;
				continue;
			}
			if (curaddr != region_end) {
				printf("0x%08lX to 0x%08lX (%lu bytes)\n",
					region_start, region_end,
					region_end - region_start);
				region_start = curaddr;
			}
			region_end = curaddr + datalen;
			continue;
		case '7':
			if (srecbin[0] < 5) {
				fprintf(stderr,
					"%s line %d: S7 record is too short\n",
					infname, lineno);
				exit(1);
			}
			printf("0x%08lX to 0x%08lX (%lu bytes)\n",
				region_start, region_end,
				region_end - region_start);
			printf("S7 address 0x%02X%02X%02X%02X\n", srecbin[1],
				srecbin[2], srecbin[3], srecbin[4]);
			exit(0);
		default:
			abort();
		}
	}
}