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/module.h>
30
31#include <uapi/linux/magic.h>
32
33#define AR7_PARTS	4
34#define ROOT_OFFSET	0xe0000
35
36#define LOADER_MAGIC1	le32_to_cpu(0xfeedfa42)
37#define LOADER_MAGIC2	le32_to_cpu(0xfeed1281)
38
39struct ar7_bin_rec {
40	unsigned int checksum;
41	unsigned int length;
42	unsigned int address;
43};
44
45static int create_mtd_partitions(struct mtd_info *master,
46				 struct mtd_partition **pparts,
47				 struct mtd_part_parser_data *data)
48{
49	struct ar7_bin_rec header;
50	unsigned int offset;
51	size_t len;
52	unsigned int pre_size = master->erasesize, post_size = 0;
53	unsigned int root_offset = ROOT_OFFSET;
54
55	int retries = 10;
56	struct mtd_partition *ar7_parts;
57
58	ar7_parts = kzalloc(sizeof(*ar7_parts) * AR7_PARTS, GFP_KERNEL);
59	if (!ar7_parts)
60		return -ENOMEM;
61	ar7_parts[0].name = "loader";
62	ar7_parts[0].offset = 0;
63	ar7_parts[0].size = master->erasesize;
64	ar7_parts[0].mask_flags = MTD_WRITEABLE;
65
66	ar7_parts[1].name = "config";
67	ar7_parts[1].offset = 0;
68	ar7_parts[1].size = master->erasesize;
69	ar7_parts[1].mask_flags = 0;
70
71	do { /* Try 10 blocks starting from master->erasesize */
72		offset = pre_size;
73		mtd_read(master, offset, sizeof(header), &len,
74			 (uint8_t *)&header);
75		if (!strncmp((char *)&header, "TIENV0.8", 8))
76			ar7_parts[1].offset = pre_size;
77		if (header.checksum == LOADER_MAGIC1)
78			break;
79		if (header.checksum == LOADER_MAGIC2)
80			break;
81		pre_size += master->erasesize;
82	} while (retries--);
83
84	pre_size = offset;
85
86	if (!ar7_parts[1].offset) {
87		ar7_parts[1].offset = master->size - master->erasesize;
88		post_size = master->erasesize;
89	}
90
91	switch (header.checksum) {
92	case LOADER_MAGIC1:
93		while (header.length) {
94			offset += sizeof(header) + header.length;
95			mtd_read(master, offset, sizeof(header), &len,
96				 (uint8_t *)&header);
97		}
98		root_offset = offset + sizeof(header) + 4;
99		break;
100	case LOADER_MAGIC2:
101		while (header.length) {
102			offset += sizeof(header) + header.length;
103			mtd_read(master, offset, sizeof(header), &len,
104				 (uint8_t *)&header);
105		}
106		root_offset = offset + sizeof(header) + 4 + 0xff;
107		root_offset &= ~(uint32_t)0xff;
108		break;
109	default:
110		printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
111		break;
112	}
113
114	mtd_read(master, root_offset, sizeof(header), &len, (u8 *)&header);
115	if (header.checksum != SQUASHFS_MAGIC) {
116		root_offset += master->erasesize - 1;
117		root_offset &= ~(master->erasesize - 1);
118	}
119
120	ar7_parts[2].name = "linux";
121	ar7_parts[2].offset = pre_size;
122	ar7_parts[2].size = master->size - pre_size - post_size;
123	ar7_parts[2].mask_flags = 0;
124
125	ar7_parts[3].name = "rootfs";
126	ar7_parts[3].offset = root_offset;
127	ar7_parts[3].size = master->size - root_offset - post_size;
128	ar7_parts[3].mask_flags = 0;
129
130	*pparts = ar7_parts;
131	return AR7_PARTS;
132}
133
134static struct mtd_part_parser ar7_parser = {
135	.owner = THIS_MODULE,
136	.parse_fn = create_mtd_partitions,
137	.name = "ar7part",
138};
139
140static int __init ar7_parser_init(void)
141{
142	register_mtd_parser(&ar7_parser);
143	return 0;
144}
145
146static void __exit ar7_parser_exit(void)
147{
148	deregister_mtd_parser(&ar7_parser);
149}
150
151module_init(ar7_parser_init);
152module_exit(ar7_parser_exit);
153
154MODULE_LICENSE("GPL");
155MODULE_AUTHOR(	"Felix Fietkau <nbd@openwrt.org>, "
156		"Eugene Konev <ejka@openwrt.org>");
157MODULE_DESCRIPTION("MTD partitioning for TI AR7");
158