2 * Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published
6 * by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/mtd/mtd.h>
15 #include <linux/mtd/partitions.h>
16 #include <linux/byteorder/generic.h>
20 #define SEAMA_MAGIC 0x5EA3A417
21 #define SEAMA_NR_PARTS 2
22 #define SEAMA_MIN_ROOTFS_OFFS 0x80000 /* 512KiB */
25 __be32 magic; /* should always be SEAMA_MAGIC. */
26 __be16 reserved; /* reserved for */
27 __be16 metasize; /* size of the META data */
28 __be32 size; /* size of the image */
29 u8 md5[16]; /* digest */
32 static int mtdsplit_parse_seama(struct mtd_info *master,
33 const struct mtd_partition **pparts,
34 struct mtd_part_parser_data *data)
36 struct seama_header hdr;
37 size_t hdr_len, retlen, kernel_ent_size;
39 struct mtd_partition *parts;
40 enum mtdsplit_part_type type;
43 hdr_len = sizeof(hdr);
44 err = mtd_read(master, 0, hdr_len, &retlen, (void *) &hdr);
48 if (retlen != hdr_len)
52 if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC)
55 kernel_ent_size = hdr_len + be32_to_cpu(hdr.size) +
56 be16_to_cpu(hdr.metasize);
57 if (kernel_ent_size > master->size)
60 /* Check for the rootfs right after Seama entity with a kernel. */
61 err = mtd_check_rootfs_magic(master, kernel_ent_size, &type);
63 rootfs_offset = kernel_ent_size;
66 * On some devices firmware entity might contain both: kernel
67 * and rootfs. We can't determine kernel size so we just have to
68 * look for rootfs magic.
69 * Start the search from an arbitrary offset.
71 err = mtd_find_rootfs_from(master, SEAMA_MIN_ROOTFS_OFFS,
72 master->size, &rootfs_offset, &type);
77 parts = kzalloc(SEAMA_NR_PARTS * sizeof(*parts), GFP_KERNEL);
81 parts[0].name = KERNEL_PART_NAME;
82 parts[0].offset = sizeof hdr + be16_to_cpu(hdr.metasize);
83 parts[0].size = rootfs_offset - parts[0].offset;
85 if (type == MTDSPLIT_PART_TYPE_UBI)
86 parts[1].name = UBI_PART_NAME;
88 parts[1].name = ROOTFS_PART_NAME;
89 parts[1].offset = rootfs_offset;
90 parts[1].size = master->size - rootfs_offset;
93 return SEAMA_NR_PARTS;
96 static struct mtd_part_parser mtdsplit_seama_parser = {
99 .parse_fn = mtdsplit_parse_seama,
100 .type = MTD_PARSER_TYPE_FIRMWARE,
103 static int __init mtdsplit_seama_init(void)
105 register_mtd_parser(&mtdsplit_seama_parser);
110 subsys_initcall(mtdsplit_seama_init);