ar7part.c revision 17b536cc43bcf2afcc20b4812f93a895881b5f4f 
1/*
2 * Copyright © 2007 Eugene Konev <ejka@openwrt.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 *
18 * TI AR7 flash partition table.
19 * Based on ar7 map by Felix Fietkau <nbd@openwrt.org>
20 *
21 */
22
23#include <linux/kernel.h>
24#include <linux/slab.h>
25
26#include <linux/mtd/mtd.h>
27#include <linux/mtd/partitions.h>
28#include <linux/bootmem.h>
29#include <linux/magic.h>
30
31#define AR7_PARTS	4
32#define ROOT_OFFSET	0xe0000
33
34#define LOADER_MAGIC1	le32_to_cpu(0xfeedfa42)
35#define LOADER_MAGIC2	le32_to_cpu(0xfeed1281)
36
37#ifndef SQUASHFS_MAGIC
38#define SQUASHFS_MAGIC	0x73717368
39#endif
40
41struct ar7_bin_rec {
42	unsigned int checksum;
43	unsigned int length;
44	unsigned int address;
45};
46
47static int create_mtd_partitions(struct mtd_info *master,
48				 struct mtd_partition **pparts,
49				 unsigned long origin)
50{
51	struct ar7_bin_rec header;
52	unsigned int offset;
53	size_t len;
54	unsigned int pre_size = master->erasesize, post_size = 0;
55	unsigned int root_offset = ROOT_OFFSET;
56
57	int retries = 10;
58	struct mtd_partition *ar7_parts;
59
60	ar7_parts = kzalloc(sizeof(*ar7_parts) * AR7_PARTS, GFP_KERNEL);
61	if (!ar7_parts)
62		return -ENOMEM;
63	ar7_parts[0].name = "loader";
64	ar7_parts[0].offset = 0;
65	ar7_parts[0].size = master->erasesize;
66	ar7_parts[0].mask_flags = MTD_WRITEABLE;
67
68	ar7_parts[1].name = "config";
69	ar7_parts[1].offset = 0;
70	ar7_parts[1].size = master->erasesize;
71	ar7_parts[1].mask_flags = 0;
72
73	do { /* Try 10 blocks starting from master->erasesize */
74		offset = pre_size;
75		master->read(master, offset,
76			     sizeof(header), &len, (uint8_t *)&header);
77		if (!strncmp((char *)&header, "TIENV0.8", 8))
78			ar7_parts[1].offset = pre_size;
79		if (header.checksum == LOADER_MAGIC1)
80			break;
81		if (header.checksum == LOADER_MAGIC2)
82			break;
83		pre_size += master->erasesize;
84	} while (retries--);
85
86	pre_size = offset;
87
88	if (!ar7_parts[1].offset) {
89		ar7_parts[1].offset = master->size - master->erasesize;
90		post_size = master->erasesize;
91	}
92
93	switch (header.checksum) {
94	case LOADER_MAGIC1:
95		while (header.length) {
96			offset += sizeof(header) + header.length;
97			master->read(master, offset, sizeof(header),
98				     &len, (uint8_t *)&header);
99		}
100		root_offset = offset + sizeof(header) + 4;
101		break;
102	case LOADER_MAGIC2:
103		while (header.length) {
104			offset += sizeof(header) + header.length;
105			master->read(master, offset, sizeof(header),
106				     &len, (uint8_t *)&header);
107		}
108		root_offset = offset + sizeof(header) + 4 + 0xff;
109		root_offset &= ~(uint32_t)0xff;
110		break;
111	default:
112		printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
113		break;
114	}
115
116	master->read(master, root_offset,
117		sizeof(header), &len, (u8 *)&header);
118	if (header.checksum != SQUASHFS_MAGIC) {
119		root_offset += master->erasesize - 1;
120		root_offset &= ~(master->erasesize - 1);
121	}
122
123	ar7_parts[2].name = "linux";
124	ar7_parts[2].offset = pre_size;
125	ar7_parts[2].size = master->size - pre_size - post_size;
126	ar7_parts[2].mask_flags = 0;
127
128	ar7_parts[3].name = "rootfs";
129	ar7_parts[3].offset = root_offset;
130	ar7_parts[3].size = master->size - root_offset - post_size;
131	ar7_parts[3].mask_flags = 0;
132
133	*pparts = ar7_parts;
134	return AR7_PARTS;
135}
136
137static struct mtd_part_parser ar7_parser = {
138	.owner = THIS_MODULE,
139	.parse_fn = create_mtd_partitions,
140	.name = "ar7part",
141};
142
143static int __init ar7_parser_init(void)
144{
145	return register_mtd_parser(&ar7_parser);
146}
147
148module_init(ar7_parser_init);
149
150MODULE_LICENSE("GPL");
151MODULE_AUTHOR(	"Felix Fietkau <nbd@openwrt.org>, "
152		"Eugene Konev <ejka@openwrt.org>");
153MODULE_DESCRIPTION("MTD partitioning for TI AR7");
154