/* * Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * */ #include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include <linux/byteorder/generic.h> #include "mtdsplit.h" #define SEAMA_MAGIC 0x5EA3A417 #define SEAMA_NR_PARTS 2 #define SEAMA_MIN_ROOTFS_OFFS 0x80000 /* 512KiB */ struct seama_header { __be32 magic; /* should always be SEAMA_MAGIC. */ __be16 reserved; /* reserved for */ __be16 metasize; /* size of the META data */ __be32 size; /* size of the image */ }; static int mtdsplit_parse_seama(struct mtd_info *master, struct mtd_partition **pparts, struct mtd_part_parser_data *data) { struct seama_header hdr; size_t hdr_len, retlen, kernel_size; size_t rootfs_offset; struct mtd_partition *parts; int err; hdr_len = sizeof(hdr); err = mtd_read(master, 0, hdr_len, &retlen, (void *) &hdr); if (err) return err; if (retlen != hdr_len) return -EIO; /* sanity checks */ if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC) return -EINVAL; kernel_size = hdr_len + be32_to_cpu(hdr.size) + be16_to_cpu(hdr.metasize); if (kernel_size > master->size) return -EINVAL; /* Find the rootfs after the kernel. */ err = mtd_check_rootfs_magic(master, kernel_size); if (!err) { rootfs_offset = kernel_size; } else { /* * The size in the header might cover the rootfs as well. * Start the search from an arbitrary offset. */ err = mtd_find_rootfs_from(master, SEAMA_MIN_ROOTFS_OFFS, master->size, &rootfs_offset); if (err) return err; } parts = kzalloc(SEAMA_NR_PARTS * sizeof(*parts), GFP_KERNEL); if (!parts) return -ENOMEM; parts[0].name = KERNEL_PART_NAME; parts[0].offset = 0; parts[0].size = rootfs_offset; parts[1].name = ROOTFS_PART_NAME; parts[1].offset = rootfs_offset; parts[1].size = master->size - rootfs_offset; *pparts = parts; return SEAMA_NR_PARTS; } static struct mtd_part_parser mtdsplit_seama_parser = { .owner = THIS_MODULE, .name = "seama-fw", .parse_fn = mtdsplit_parse_seama, .type = MTD_PARSER_TYPE_FIRMWARE, }; static int __init mtdsplit_seama_init(void) { register_mtd_parser(&mtdsplit_seama_parser); return 0; } subsys_initcall(mtdsplit_seama_init);