| 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"); |
| 179 | |
