105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/*
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* Copyright (C) 2012 John Crispin <blogic@openwrt.org>
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* Copyright (C) 2015 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/partitions.h>
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#include <linux/byteorder/generic.h>
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#include "mtdsplit.h"
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#define BRNIMAGE_NR_PARTS 2
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#define BRNIMAGE_ALIGN_BYTES 0x400
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#define BRNIMAGE_FOOTER_SIZE 12
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#define BRNIMAGE_MIN_OVERHEAD (BRNIMAGE_FOOTER_SIZE)
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#define BRNIMAGE_MAX_OVERHEAD (BRNIMAGE_ALIGN_BYTES + BRNIMAGE_FOOTER_SIZE)
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static int mtdsplit_parse_brnimage(struct mtd_info *master,
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const struct mtd_partition **pparts,
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struct mtd_part_parser_data *data)
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{
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struct mtd_partition *parts;
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uint32_t buf;
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unsigned long rootfs_offset, rootfs_size, kernel_size;
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size_t len;
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int ret = 0;
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for (rootfs_offset = 0; rootfs_offset < master->size;
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rootfs_offset += BRNIMAGE_ALIGN_BYTES) {
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ret = mtd_check_rootfs_magic(master, rootfs_offset, NULL);
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if (!ret)
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break;
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}
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if (ret)
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return ret;
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if (rootfs_offset >= master->size)
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return -EINVAL;
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ret = mtd_read(master, rootfs_offset - BRNIMAGE_FOOTER_SIZE, 4, &len,
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(void *)&buf);
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if (ret)
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return ret;
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if (len != 4)
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return -EIO;
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kernel_size = le32_to_cpu(buf);
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if (kernel_size > (rootfs_offset - BRNIMAGE_MIN_OVERHEAD))
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return -EINVAL;
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if (kernel_size < (rootfs_offset - BRNIMAGE_MAX_OVERHEAD))
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return -EINVAL;
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/*
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* The footer must be untouched as it contains the checksum of the
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* original brnImage (kernel + squashfs)!
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*/
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rootfs_size = master->size - rootfs_offset - BRNIMAGE_FOOTER_SIZE;
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parts = kzalloc(BRNIMAGE_NR_PARTS * sizeof(*parts), GFP_KERNEL);
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if (!parts)
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return -ENOMEM;
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parts[0].name = KERNEL_PART_NAME;
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parts[0].offset = 0;
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parts[0].size = kernel_size;
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parts[1].name = ROOTFS_PART_NAME;
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parts[1].offset = rootfs_offset;
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parts[1].size = rootfs_size;
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*pparts = parts;
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return BRNIMAGE_NR_PARTS;
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}
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static struct mtd_part_parser mtdsplit_brnimage_parser = {
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.owner = THIS_MODULE,
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.name = "brnimage-fw",
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.parse_fn = mtdsplit_parse_brnimage,
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.type = MTD_PARSER_TYPE_FIRMWARE,
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};
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static int __init mtdsplit_brnimage_init(void)
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{
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register_mtd_parser(&mtdsplit_brnimage_parser);
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return 0;
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}
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subsys_initcall(mtdsplit_brnimage_init);
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