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 #include <linux/module.h>
31 
32 #define AR7_PARTS	4
33 #define ROOT_OFFSET	0xe0000
34 
35 #define LOADER_MAGIC1	le32_to_cpu(0xfeedfa42)
36 #define LOADER_MAGIC2	le32_to_cpu(0xfeed1281)
37 
38 #ifndef SQUASHFS_MAGIC
39 #define SQUASHFS_MAGIC	0x73717368
40 #endif
41 
42 struct ar7_bin_rec {
43 	unsigned int checksum;
44 	unsigned int length;
45 	unsigned int address;
46 };
47 
create_mtd_partitions(struct mtd_info * master,struct mtd_partition ** pparts,struct mtd_part_parser_data * data)48 static int create_mtd_partitions(struct mtd_info *master,
49 				 struct mtd_partition **pparts,
50 				 struct mtd_part_parser_data *data)
51 {
52 	struct ar7_bin_rec header;
53 	unsigned int offset;
54 	size_t len;
55 	unsigned int pre_size = master->erasesize, post_size = 0;
56 	unsigned int root_offset = ROOT_OFFSET;
57 
58 	int retries = 10;
59 	struct mtd_partition *ar7_parts;
60 
61 	ar7_parts = kzalloc(sizeof(*ar7_parts) * AR7_PARTS, GFP_KERNEL);
62 	if (!ar7_parts)
63 		return -ENOMEM;
64 	ar7_parts[0].name = "loader";
65 	ar7_parts[0].offset = 0;
66 	ar7_parts[0].size = master->erasesize;
67 	ar7_parts[0].mask_flags = MTD_WRITEABLE;
68 
69 	ar7_parts[1].name = "config";
70 	ar7_parts[1].offset = 0;
71 	ar7_parts[1].size = master->erasesize;
72 	ar7_parts[1].mask_flags = 0;
73 
74 	do { /* Try 10 blocks starting from master->erasesize */
75 		offset = pre_size;
76 		mtd_read(master, offset, sizeof(header), &len,
77 			 (uint8_t *)&header);
78 		if (!strncmp((char *)&header, "TIENV0.8", 8))
79 			ar7_parts[1].offset = pre_size;
80 		if (header.checksum == LOADER_MAGIC1)
81 			break;
82 		if (header.checksum == LOADER_MAGIC2)
83 			break;
84 		pre_size += master->erasesize;
85 	} while (retries--);
86 
87 	pre_size = offset;
88 
89 	if (!ar7_parts[1].offset) {
90 		ar7_parts[1].offset = master->size - master->erasesize;
91 		post_size = master->erasesize;
92 	}
93 
94 	switch (header.checksum) {
95 	case LOADER_MAGIC1:
96 		while (header.length) {
97 			offset += sizeof(header) + header.length;
98 			mtd_read(master, offset, sizeof(header), &len,
99 				 (uint8_t *)&header);
100 		}
101 		root_offset = offset + sizeof(header) + 4;
102 		break;
103 	case LOADER_MAGIC2:
104 		while (header.length) {
105 			offset += sizeof(header) + header.length;
106 			mtd_read(master, offset, sizeof(header), &len,
107 				 (uint8_t *)&header);
108 		}
109 		root_offset = offset + sizeof(header) + 4 + 0xff;
110 		root_offset &= ~(uint32_t)0xff;
111 		break;
112 	default:
113 		printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
114 		break;
115 	}
116 
117 	mtd_read(master, root_offset, 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 
137 static struct mtd_part_parser ar7_parser = {
138 	.owner = THIS_MODULE,
139 	.parse_fn = create_mtd_partitions,
140 	.name = "ar7part",
141 };
142 
ar7_parser_init(void)143 static int __init ar7_parser_init(void)
144 {
145 	return register_mtd_parser(&ar7_parser);
146 }
147 
148 module_init(ar7_parser_init);
149 
150 MODULE_LICENSE("GPL");
151 MODULE_AUTHOR(	"Felix Fietkau <nbd@openwrt.org>, "
152 		"Eugene Konev <ejka@openwrt.org>");
153 MODULE_DESCRIPTION("MTD partitioning for TI AR7");
154