134 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			134 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Parser for TRX format partitions
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 *
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 * Copyright (C) 2012 - 2017 Rafał Miłecki <rafal@milecki.pl>
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published 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/slab.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/partitions.h>
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#define TRX_PARSER_MAX_PARTS		4
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/* Magics */
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#define TRX_MAGIC			0x30524448
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#define UBI_EC_MAGIC			0x23494255	/* UBI# */
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struct trx_header {
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	uint32_t magic;
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	uint32_t length;
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	uint32_t crc32;
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	uint16_t flags;
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	uint16_t version;
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	uint32_t offset[3];
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} __packed;
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static const char *parser_trx_data_part_name(struct mtd_info *master,
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					     size_t offset)
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{
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	uint32_t buf;
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	size_t bytes_read;
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	int err;
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	err  = mtd_read(master, offset, sizeof(buf), &bytes_read,
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			(uint8_t *)&buf);
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	if (err && !mtd_is_bitflip(err)) {
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		pr_err("mtd_read error while parsing (offset: 0x%zX): %d\n",
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			offset, err);
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		goto out_default;
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	}
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	if (buf == UBI_EC_MAGIC)
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		return "ubi";
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out_default:
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	return "rootfs";
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}
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static int parser_trx_parse(struct mtd_info *mtd,
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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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	struct mtd_partition *part;
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	struct trx_header trx;
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	size_t bytes_read;
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	uint8_t curr_part = 0, i = 0;
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	int err;
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	parts = kcalloc(TRX_PARSER_MAX_PARTS, sizeof(struct mtd_partition),
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			GFP_KERNEL);
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	if (!parts)
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		return -ENOMEM;
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	err = mtd_read(mtd, 0, sizeof(trx), &bytes_read, (uint8_t *)&trx);
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	if (err) {
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		pr_err("MTD reading error: %d\n", err);
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		kfree(parts);
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		return err;
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	}
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	if (trx.magic != TRX_MAGIC) {
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		kfree(parts);
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		return -ENOENT;
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	}
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	/* We have LZMA loader if there is address in offset[2] */
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	if (trx.offset[2]) {
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		part = &parts[curr_part++];
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		part->name = "loader";
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		part->offset = trx.offset[i];
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		i++;
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	}
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	if (trx.offset[i]) {
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		part = &parts[curr_part++];
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		part->name = "linux";
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		part->offset = trx.offset[i];
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		i++;
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	}
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	if (trx.offset[i]) {
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		part = &parts[curr_part++];
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		part->name = parser_trx_data_part_name(mtd, trx.offset[i]);
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		part->offset = trx.offset[i];
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		i++;
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	}
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	/*
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	 * Assume that every partition ends at the beginning of the one it is
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	 * followed by.
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	 */
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	for (i = 0; i < curr_part; i++) {
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		u64 next_part_offset = (i < curr_part - 1) ?
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				       parts[i + 1].offset : mtd->size;
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		parts[i].size = next_part_offset - parts[i].offset;
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	}
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	*pparts = parts;
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	return i;
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};
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static const struct of_device_id mtd_parser_trx_of_match_table[] = {
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	{ .compatible = "brcm,trx" },
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	{},
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};
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MODULE_DEVICE_TABLE(of, mtd_parser_trx_of_match_table);
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static struct mtd_part_parser mtd_parser_trx = {
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	.parse_fn = parser_trx_parse,
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	.name = "trx",
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	.of_match_table = mtd_parser_trx_of_match_table,
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};
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module_mtd_part_parser(mtd_parser_trx);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("Parser for TRX format partitions");
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