view miscutil/mokosrec2bin.c @ 465:003e48f8ebe1

rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel I generally don't use NULL and use plain 0 instead, based on a "NULL considered harmful" discussion on the classiccmp mailing list many aeons ago (I couldn't find it, and I reason that it must have been 2005 or earlier), but a recent complaint by a packager sent me searching, and I found this: https://ewontfix.com/11/ While I don't give a @#$% about "modern" systems and code-nazi tools, I realized that passing a plain 0 as a pointer sentinel in execl is wrong because it will break on systems where pointers are longer than the plain int type. Again, I don't give a @#$% about the abomination of x86_64 and the like, but if anyone ever manages to port my code to something like a PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0 as a function argument where a pointer is expected most definitely won't work: if the most natural stack slot and SP alignment unit is 16 bits, fitting an int, with longs and pointers taking up two such slots, then the call stack will be totally wrong with a plain 0 passed for a pointer. Casting the 0 to (char *) ought to be the most kosher solution for the most retro systems possible.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 11 Feb 2019 00:00:19 +0000
parents a5dab452be0d
children d00ffedacab5
line wrap: on
line source

/*
 * GSM device firmwares that are built with TI's TMS470 toolchain in TI's
 * canonical way come out in TI's *.m0 format produced by TI's hex470 tool.
 * TI's *.m0 is a variant of the classic S-record format from Motorola,
 * but the specific variant depends on the -memwidth and -romwidth options
 * with which the hex470 tool is run.
 *
 * In TI's canonical architecture (as opposed to Mot/Compal's heavily modified
 * version) this hex470 tool is run with -memwidth 16 -romwidth 16 options,
 * and the *.m0 file comes out in the format variant which we have nicknamed
 * "moko-style" after its most famous user.  This variant is a byte-reversed
 * S-record format in that each 16-bit word is byte-reversed relative to the
 * native byte order of the ARM7 processor.  (This strange byte order actually
 * makes some sense if one views the image as a long array of 16-bit hex
 * values; 16 bits is the width of the flash memory on Calypso GSM devices and
 * thus the natural unit size for flash programming.)
 *
 * The present mokosrec2bin utility converts these "moko-style" S-record files
 * to straight binary, a conversion that includes flipping the order of bytes.
 */

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

char *infname;
FILE *inf, *outf;
u_char fillbyte;
char srecbuf[80];
u_char srecbin[40];
int lineno, state;
u_long lastaddr;

u_char header[6] = {0x06, 0x00, 0x00, 'H', 'D', 'R'};

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;
	if (l > 35) {
		fprintf(stderr,
			"%s line %d: S-record is longer than expected\n",
			infname, lineno);
		exit(1);
	}
	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 < 3 || argc > 4) {
usage:		fprintf(stderr, "usage: %s input.m0 output.bin [fill-byte]\n",
			argv[0]);
		exit(1);
	}
	infname = argv[1];
	inf = fopen(infname, "r");
	if (!inf) {
		perror(infname);
		exit(1);
	}
	if (argc > 3) {
		i = decode_hex_byte(argv[3]);
		if (i >= 0)
			fillbyte = i;
		else
			goto usage;
	} else
		fillbyte = 0;

	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();
		if (state == 0) {
			if (bcmp(srecbin, header, 6)) {
				fprintf(stderr, "%s: expected header missing\n",
					infname);
				exit(1);
			}
			state = 1;
			continue;
		}
		switch (srecbuf[1]) {
		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];
			if (curaddr & 1) {
				fprintf(stderr, "%s line %d: odd address\n",
					infname, lineno);
				exit(1);
			}
			datalen = srecbin[0] - 5;
			if (datalen & 1) {
				fprintf(stderr, "%s line %d: odd data length\n",
					infname, lineno);
				exit(1);
			}
			if (state < 2) {
				outf = fopen(argv[2], "w");
				if (!outf) {
					perror(argv[2]);
					exit(1);
				}
				state = 2;
				lastaddr = 0;
			}
			if (curaddr < lastaddr) {
				fprintf(stderr,
					"%s line %d: address going backwards\n",
					infname, lineno);
				exit(1);
			}
			while (lastaddr < curaddr) {
				putc(fillbyte, outf);
				lastaddr++;
			}
			for (i = 0; i < datalen; i += 2) {
				putc(srecbin[i + 6], outf);
				putc(srecbin[i + 5], outf);
			}
			lastaddr = curaddr + datalen;
			continue;
		case '7':
			fclose(outf);
			exit(0);
		default:
			abort();
		}
	}
}