summaryrefslogtreecommitdiff
path: root/drivers/mtd/bcm63xxpart.c
blob: 8b86ed69522ec7d8ff458adabe401aeba9df2f45 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*
 * BCM63XX CFE image tag parser
 *
 * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
 *			  Mike Albon <malbon@openwrt.org>
 * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
 * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bcm963xx_tag.h>
#include <linux/crc32.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>

#include <asm/mach-bcm63xx/bcm63xx_nvram.h>
#include <asm/mach-bcm63xx/board_bcm963xx.h>

#define BCM63XX_EXTENDED_SIZE	0xBFC00000	/* Extended flash address */

#define BCM63XX_CFE_BLOCK_SIZE	SZ_64K		/* always at least 64KiB */

#define BCM63XX_CFE_MAGIC_OFFSET 0x4e0

static int bcm63xx_detect_cfe(struct mtd_info *master)
{
	char buf[9];
	int ret;
	size_t retlen;

	ret = mtd_read(master, BCM963XX_CFE_VERSION_OFFSET, 5, &retlen,
		       (void *)buf);
	buf[retlen] = 0;

	if (ret)
		return ret;

	if (strncmp("cfe-v", buf, 5) == 0)
		return 0;

	/* very old CFE's do not have the cfe-v string, so check for magic */
	ret = mtd_read(master, BCM63XX_CFE_MAGIC_OFFSET, 8, &retlen,
		       (void *)buf);
	buf[retlen] = 0;

	return strncmp("CFE1CFE1", buf, 8);
}

static int bcm63xx_parse_cfe_partitions(struct mtd_info *master,
					struct mtd_partition **pparts,
					struct mtd_part_parser_data *data)
{
	/* CFE, NVRAM and global Linux are always present */
	int nrparts = 3, curpart = 0;
	struct bcm_tag *buf;
	struct mtd_partition *parts;
	int ret;
	size_t retlen;
	unsigned int rootfsaddr, kerneladdr, spareaddr;
	unsigned int rootfslen, kernellen, sparelen, totallen;
	unsigned int cfelen, nvramlen;
	unsigned int cfe_erasesize;
	int i;
	u32 computed_crc;
	bool rootfs_first = false;

	if (bcm63xx_detect_cfe(master))
		return -EINVAL;

	cfe_erasesize = max_t(uint32_t, master->erasesize,
			      BCM63XX_CFE_BLOCK_SIZE);

	cfelen = cfe_erasesize;
	nvramlen = bcm63xx_nvram_get_psi_size() * SZ_1K;
	nvramlen = roundup(nvramlen, cfe_erasesize);

	/* Allocate memory for buffer */
	buf = vmalloc(sizeof(struct bcm_tag));
	if (!buf)
		return -ENOMEM;

	/* Get the tag */
	ret = mtd_read(master, cfelen, sizeof(struct bcm_tag), &retlen,
		       (void *)buf);

	if (retlen != sizeof(struct bcm_tag)) {
		vfree(buf);
		return -EIO;
	}

	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
				offsetof(struct bcm_tag, header_crc));
	if (computed_crc == buf->header_crc) {
		char *boardid = &(buf->board_id[0]);
		char *tagversion = &(buf->tag_version[0]);

		sscanf(buf->flash_image_start, "%u", &rootfsaddr);
		sscanf(buf->kernel_address, "%u", &kerneladdr);
		sscanf(buf->kernel_length, "%u", &kernellen);
		sscanf(buf->total_length, "%u", &totallen);

		pr_info("CFE boot tag found with version %s and board type %s\n",
			tagversion, boardid);

		kerneladdr = kerneladdr - BCM63XX_EXTENDED_SIZE;
		rootfsaddr = rootfsaddr - BCM63XX_EXTENDED_SIZE;
		spareaddr = roundup(totallen, master->erasesize) + cfelen;

		if (rootfsaddr < kerneladdr) {
			/* default Broadcom layout */
			rootfslen = kerneladdr - rootfsaddr;
			rootfs_first = true;
		} else {
			/* OpenWrt layout */
			rootfsaddr = kerneladdr + kernellen;
			rootfslen = spareaddr - rootfsaddr;
		}
	} else {
		pr_warn("CFE boot tag CRC invalid (expected %08x, actual %08x)\n",
			buf->header_crc, computed_crc);
		kernellen = 0;
		rootfslen = 0;
		rootfsaddr = 0;
		spareaddr = cfelen;
	}
	sparelen = master->size - spareaddr - nvramlen;

	/* Determine number of partitions */
	if (rootfslen > 0)
		nrparts++;

	if (kernellen > 0)
		nrparts++;

	/* Ask kernel for more memory */
	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
	if (!parts) {
		vfree(buf);
		return -ENOMEM;
	}

	/* Start building partition list */
	parts[curpart].name = "CFE";
	parts[curpart].offset = 0;
	parts[curpart].size = cfelen;
	curpart++;

	if (kernellen > 0) {
		int kernelpart = curpart;

		if (rootfslen > 0 && rootfs_first)
			kernelpart++;
		parts[kernelpart].name = "kernel";
		parts[kernelpart].offset = kerneladdr;
		parts[kernelpart].size = kernellen;
		curpart++;
	}

	if (rootfslen > 0) {
		int rootfspart = curpart;

		if (kernellen > 0 && rootfs_first)
			rootfspart--;
		parts[rootfspart].name = "rootfs";
		parts[rootfspart].offset = rootfsaddr;
		parts[rootfspart].size = rootfslen;
		if (sparelen > 0  && !rootfs_first)
			parts[rootfspart].size += sparelen;
		curpart++;
	}

	parts[curpart].name = "nvram";
	parts[curpart].offset = master->size - nvramlen;
	parts[curpart].size = nvramlen;
	curpart++;

	/* Global partition "linux" to make easy firmware upgrade */
	parts[curpart].name = "linux";
	parts[curpart].offset = cfelen;
	parts[curpart].size = master->size - cfelen - nvramlen;

	for (i = 0; i < nrparts; i++)
		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
			parts[i].name, parts[i].offset,	parts[i].size);

	pr_info("Spare partition is offset %x and length %x\n",	spareaddr,
		sparelen);

	*pparts = parts;
	vfree(buf);

	return nrparts;
};

static struct mtd_part_parser bcm63xx_cfe_parser = {
	.owner = THIS_MODULE,
	.parse_fn = bcm63xx_parse_cfe_partitions,
	.name = "bcm63xxpart",
};

static int __init bcm63xx_cfe_parser_init(void)
{
	register_mtd_parser(&bcm63xx_cfe_parser);
	return 0;
}

static void __exit bcm63xx_cfe_parser_exit(void)
{
	deregister_mtd_parser(&bcm63xx_cfe_parser);
}

module_init(bcm63xx_cfe_parser_init);
module_exit(bcm63xx_cfe_parser_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com");
MODULE_DESCRIPTION("MTD partitioning for BCM63XX CFE bootloaders");