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 */
31 static int mtdsplit_parse_seama(struct mtd_info
*master
,
32 struct mtd_partition
**pparts
,
33 struct mtd_part_parser_data
*data
)
35 struct seama_header hdr
;
36 size_t hdr_len
, retlen
, kernel_ent_size
;
38 struct mtd_partition
*parts
;
41 hdr_len
= sizeof(hdr
);
42 err
= mtd_read(master
, 0, hdr_len
, &retlen
, (void *) &hdr
);
46 if (retlen
!= hdr_len
)
50 if (be32_to_cpu(hdr
.magic
) != SEAMA_MAGIC
)
53 kernel_ent_size
= hdr_len
+ be32_to_cpu(hdr
.size
) +
54 be16_to_cpu(hdr
.metasize
);
55 if (kernel_ent_size
> master
->size
)
58 /* Check for the rootfs right after Seama entity with a kernel. */
59 err
= mtd_check_rootfs_magic(master
, kernel_ent_size
);
61 rootfs_offset
= kernel_ent_size
;
64 * On some devices firmware entity might contain both: kernel
65 * and rootfs. We can't determine kernel size so we just have to
66 * look for rootfs magic.
67 * Start the search from an arbitrary offset.
69 err
= mtd_find_rootfs_from(master
, SEAMA_MIN_ROOTFS_OFFS
,
70 master
->size
, &rootfs_offset
);
75 parts
= kzalloc(SEAMA_NR_PARTS
* sizeof(*parts
), GFP_KERNEL
);
79 parts
[0].name
= KERNEL_PART_NAME
;
81 parts
[0].size
= rootfs_offset
;
83 parts
[1].name
= ROOTFS_PART_NAME
;
84 parts
[1].offset
= rootfs_offset
;
85 parts
[1].size
= master
->size
- rootfs_offset
;
88 return SEAMA_NR_PARTS
;
91 static struct mtd_part_parser mtdsplit_seama_parser
= {
94 .parse_fn
= mtdsplit_parse_seama
,
95 .type
= MTD_PARSER_TYPE_FIRMWARE
,
98 static int __init
mtdsplit_seama_init(void)
100 register_mtd_parser(&mtdsplit_seama_parser
);
105 subsys_initcall(mtdsplit_seama_init
);