[kernel] generic-2.6: make MyLoader parser compatible with the old partition tables
[openwrt/svn-archive/archive.git] / target / linux / generic-2.6 / files / drivers / mtd / myloader.c
1 /*
2 * Parse MyLoader-style flash partition tables and produce a Linux partition
3 * array to match.
4 *
5 * Copyright (C) 2007-2009 Gabor Juhos <juhosg@openwrt.org>
6 *
7 * This file was based on drivers/mtd/redboot.c
8 * Author: Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.com>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published
12 * by the Free Software Foundation.
13 *
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 #include <linux/init.h>
19 #include <linux/vmalloc.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/partitions.h>
22 #include <linux/byteorder/generic.h>
23 #include <linux/myloader.h>
24
25 #define BLOCK_LEN_MIN 0x10000
26 #define PART_NAME_LEN 32
27
28 struct part_data {
29 struct mylo_partition_table tab;
30 char names[MYLO_MAX_PARTITIONS][PART_NAME_LEN];
31 };
32
33 int myloader_parse_partitions(struct mtd_info *master,
34 struct mtd_partition **pparts,
35 unsigned long origin)
36 {
37 struct part_data *buf;
38 struct mylo_partition_table *tab;
39 struct mylo_partition *part;
40 struct mtd_partition *mtd_parts;
41 struct mtd_partition *mtd_part;
42 int num_parts;
43 int ret, i;
44 size_t retlen;
45 char *names;
46 unsigned long offset;
47 unsigned long blocklen;
48
49 buf = vmalloc(sizeof(*buf));
50 if (!buf) {
51 return -ENOMEM;
52 goto out;
53 }
54 tab = &buf->tab;
55
56 blocklen = master->erasesize;
57 if (blocklen < BLOCK_LEN_MIN)
58 blocklen = BLOCK_LEN_MIN;
59
60 offset = blocklen;
61
62 /* Find the partition table */
63 for (i = 0; i < 4; i++, offset += blocklen) {
64 printk(KERN_DEBUG "%s: searching for MyLoader partition table"
65 " at offset 0x%lx\n", master->name, offset);
66
67 ret = master->read(master, offset, sizeof(*buf), &retlen,
68 (void *)buf);
69 if (ret)
70 goto out_free_buf;
71
72 if (retlen != sizeof(*buf)) {
73 ret = -EIO;
74 goto out_free_buf;
75 }
76
77 /* Check for Partition Table magic number */
78 if (tab->magic == le32_to_cpu(MYLO_MAGIC_PARTITIONS))
79 break;
80
81 }
82
83 if (tab->magic != le32_to_cpu(MYLO_MAGIC_PARTITIONS)) {
84 printk(KERN_DEBUG "%s: no MyLoader partition table found\n",
85 master->name);
86 ret = 0;
87 goto out_free_buf;
88 }
89
90 /* The MyLoader and the Partition Table is always present */
91 num_parts = 2;
92
93 /* Detect number of used partitions */
94 for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
95 part = &tab->partitions[i];
96
97 if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
98 continue;
99
100 num_parts++;
101 }
102
103 mtd_parts = kzalloc((num_parts * sizeof(*mtd_part) +
104 num_parts * PART_NAME_LEN), GFP_KERNEL);
105
106 if (!mtd_parts) {
107 ret = -ENOMEM;
108 goto out_free_buf;
109 }
110
111 mtd_part = mtd_parts;
112 names = (char *)&mtd_parts[num_parts];
113
114 strncpy(names, "myloader", PART_NAME_LEN);
115 mtd_part->name = names;
116 mtd_part->offset = 0;
117 mtd_part->size = offset;
118 mtd_part->mask_flags = MTD_WRITEABLE;
119 mtd_part++;
120 names += PART_NAME_LEN;
121
122 strncpy(names, "partition_table", PART_NAME_LEN);
123 mtd_part->name = names;
124 mtd_part->offset = offset;
125 mtd_part->size = blocklen;
126 mtd_part->mask_flags = MTD_WRITEABLE;
127 mtd_part++;
128 names += PART_NAME_LEN;
129
130 for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
131 part = &tab->partitions[i];
132
133 if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
134 continue;
135
136 if ((buf->names[i][0]) && (buf->names[i][0] != '\xff'))
137 strncpy(names, buf->names[i], PART_NAME_LEN);
138 else
139 snprintf(names, PART_NAME_LEN, "partition%d", i);
140
141 mtd_part->offset = le32_to_cpu(part->addr);
142 mtd_part->size = le32_to_cpu(part->size);
143 mtd_part->name = names;
144 mtd_part++;
145 names += PART_NAME_LEN;
146 }
147
148 *pparts = mtd_parts;
149 ret = num_parts;
150
151 out_free_buf:
152 vfree(buf);
153 out:
154 return ret;
155 }
156
157 static struct mtd_part_parser myloader_mtd_parser = {
158 .owner = THIS_MODULE,
159 .parse_fn = myloader_parse_partitions,
160 .name = "MyLoader",
161 };
162
163 static int __init myloader_mtd_parser_init(void)
164 {
165 return register_mtd_parser(&myloader_mtd_parser);
166 }
167
168 static void __exit myloader_mtd_parser_exit(void)
169 {
170 deregister_mtd_parser(&myloader_mtd_parser);
171 }
172
173 module_init(myloader_mtd_parser_init);
174 module_exit(myloader_mtd_parser_exit);
175
176 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
177 MODULE_DESCRIPTION("Parsing code for MyLoader partition tables");
178 MODULE_LICENSE("GPL v2");