1/*
2 * motorola-bin.c
3 *
4 * Copyright (C) 2005-2006 Mike Baker,
5 *                         Imre Kaloz <kaloz@openwrt.org>
6 *                         D. Hugh Redelmeier
7 *                         OpenWrt.org
8 *
9 * $Id: motorola-bin.c 9434 2007-10-24 18:06:24Z nbd $
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
24 *
25 */
26
27/*
28 * Motorola's firmware flashing code requires an extra header.
29 * The header is eight bytes (see struct motorola below).
30 * This program will take a firmware file and create a new one
31 * with this header:
32 *	motorola-bin --wr850g WR850G_V403.stripped.trx WR850G_V403.trx
33 *
34 * Note: Motorola's firmware is distributed with this header.
35 * If you need to flash Motorola firmware on a router running OpenWRT,
36 * you will to remove this header.  Use the --strip flag:
37 *	motorola-bin --strip WR850G_V403.trx WR850G_V403.stripped.trx
38 */
39
40/*
41 * February 1, 2006
42 *
43 * Add support for for creating WA840G and WE800G images
44 */
45
46#include <stdio.h>
47#include <stdlib.h>
48#include <stddef.h>
49#include <unistd.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <sys/mman.h>
53#include <string.h>
54#include <netinet/in.h>
55#include <inttypes.h>
56
57#define BPB 8 /* bits/byte */
58
59static uint32_t crc32[1<<BPB];
60
61static void init_crc32()
62{
63	const uint32_t poly = ntohl(0x2083b8ed);
64	int n;
65
66	for (n = 0; n < 1<<BPB; n++) {
67		uint32_t crc = n;
68		int bit;
69
70		for (bit = 0; bit < BPB; bit++)
71			crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
72		crc32[n] = crc;
73	}
74}
75
76static uint32_t crc32buf(unsigned char *buf, size_t len)
77{
78	uint32_t crc = 0xFFFFFFFF;
79
80	for (; len; len--, buf++)
81		crc = crc32[(uint8_t)crc ^ *buf] ^ (crc >> BPB);
82	return crc;
83}
84
85struct motorola {
86	uint32_t crc;	// crc32 of the remainder
87	uint32_t flags;	// unknown, 105770*
88};
89
90static const struct model {
91	char digit;	/* a digit signifying model (historical) */
92	const char *name;
93	uint32_t flags;
94} models[] = {
95	{ '1', "WR850G", 0x10577050LU },
96	{ '2', "WA840G", 0x10577040LU },
97	{ '3', "WE800G", 0x10577000LU },
98	{ '\0', NULL, 0 }
99};
100
101static void usage(const char *) __attribute__ (( __noreturn__ ));
102
103static void usage(const char *mess)
104{
105	const struct model *m;
106
107	fprintf(stderr, "Error: %s\n", mess);
108	fprintf(stderr, "Usage: motorola-bin -device|--strip infile outfile\n");
109	fprintf(stderr, "Known devices: ");
110
111	for (m = models; m->digit != '\0'; m++)
112		fprintf(stderr, " %c - %s", m->digit, m->name);
113
114	fprintf(stderr, "\n");
115	exit(1);
116}
117
118int main(int argc, char **argv)
119{
120	off_t len;	// of original firmware
121	int fd;
122	void *trx;	// pointer to original firmware (mmmapped)
123	struct motorola *firmware;	// pionter to prefix + copy of original firmware
124	uint32_t flags;
125
126	// verify parameters
127
128	if (argc != 4)
129		usage("wrong number of arguments");
130
131	// mmap trx file
132	if ((fd = open(argv[2], O_RDONLY))  < 0
133	|| (len = lseek(fd, 0, SEEK_END)) < 0
134	|| (trx = mmap(0, len, PROT_READ, MAP_SHARED, fd, 0)) == (void *) (-1)
135	|| close(fd) < 0)
136	{
137		fprintf(stderr, "Error loading file %s: %s\n", argv[2], strerror(errno));
138		exit(1);
139	}
140
141	init_crc32();
142
143	if (strcmp(argv[1], "--strip") == 0)
144	{
145		const char *ugh = NULL;
146
147		if (len < sizeof(struct motorola)) {
148			ugh = "input file too short";
149		} else {
150			const struct model *m;
151
152			firmware = trx;
153			if (htonl(crc32buf(trx + offsetof(struct motorola, flags), len - offsetof(struct motorola, flags))) != firmware->crc)
154				ugh = "Invalid CRC";
155			for (m = models; ; m++) {
156				if (m->digit == '\0') {
157					if (ugh == NULL)
158						ugh = "unrecognized flags field";
159					break;
160				}
161				if (firmware->flags == htonl(m->flags)) {
162					fprintf(stderr, "Firmware for Motorola %s\n", m->name);
163					break;
164				}
165			}
166		}
167
168		if (ugh != NULL) {
169			fprintf(stderr, "%s\n", ugh);
170			exit(3);
171		} else {
172			// all is well, write the file without the prefix
173			if ((fd = open(argv[3], O_CREAT|O_WRONLY,0644)) < 0
174			|| write(fd, trx + sizeof(struct motorola), len - sizeof(struct motorola)) !=  len - sizeof(struct motorola)
175			|| close(fd) < 0)
176			{
177				fprintf(stderr, "Error storing file %s: %s\n", argv[3], strerror(errno));
178				exit(2);
179			}
180		}
181
182	} else {
183		// setup the firmware flags magic number
184		const struct model *m;
185		const char *df = argv[1];
186
187		if (*df != '-')
188			usage("first argument must start with -");
189		if (*++df == '-')
190			++df;	/* allow but don't require second - */
191
192		for (m = models; ; m++) {
193			if (m->digit == '\0')
194				usage("unrecognized device specified");
195			if ((df[0] == m->digit && df[1] == '\0') || strcasecmp(df, m->name) == 0) {
196				flags = m->flags;
197				break;
198			}
199		}
200
201
202		// create a firmware image in memory
203		// and copy the trx to it
204		firmware = malloc(sizeof(struct motorola) + len);
205		memcpy(&firmware[1], trx, len);
206
207		// setup the motorola headers
208		firmware->flags = htonl(flags);
209
210		// CRC of flags + firmware
211		firmware->crc = htonl(crc32buf((unsigned char *)&firmware->flags, sizeof(firmware->flags) + len));
212
213		// write the firmware
214		if ((fd = open(argv[3], O_CREAT|O_WRONLY,0644)) < 0
215		|| write(fd, firmware, sizeof(struct motorola) + len) != sizeof(struct motorola) + len
216		|| close(fd) < 0)
217		{
218			fprintf(stderr, "Error storing file %s: %s\n", argv[3], strerror(errno));
219			exit(2);
220		}
221
222		free(firmware);
223	}
224
225	munmap(trx,len);
226
227	return 0;
228}
229