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Commit 3cf7f131 authored by Rafał Miłecki's avatar Rafał Miłecki Committed by David Woodhouse
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mtd: bcm47part driver for BCM47XX chipsets 



This driver provides parser detecting partitions on BCM47XX flash
memories. It has many differences in comparison to BCM63XX, like:
1) Different CFE with no more trivial MAGICs
2) More partitions types (board_data, ML, POT)
3) Supporting more than 1 flash on a device
which resulted in decision of writing new parser.

It uses generic mtd interface and was successfully tested with Netgear
WNDR4500 router which has 2 flash memories: serial one and NAND one.

Signed-off-by: default avatarRafał Miłecki <zajec5@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent aa3c5dc5

drivers/mtd/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -148,6 +148,13 @@ config MTD_BCM63XX_PARTS 
	  This provides partions parsing for BCM63xx devices with CFE

	  bootloaders.



config MTD_BCM47XX_PARTS

	tristate "BCM47XX partitioning support"

	depends on BCM47XX

	help

	  This provides partitions parser for devices based on BCM47xx

	  boards.



comment "User Modules And Translation Layers"



config MTD_CHAR

drivers/mtd/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ obj-$(CONFIG_MTD_CMDLINE_PARTS) += cmdlinepart.o 
obj-$(CONFIG_MTD_AFS_PARTS)	+= afs.o

obj-$(CONFIG_MTD_AR7_PARTS)	+= ar7part.o

obj-$(CONFIG_MTD_BCM63XX_PARTS)	+= bcm63xxpart.o

obj-$(CONFIG_MTD_BCM47XX_PARTS)	+= bcm47xxpart.o



# 'Users' - code which presents functionality to userspace.

obj-$(CONFIG_MTD_CHAR)		+= mtdchar.o

drivers/mtd/bcm47xxpart.c

0 → 100644
+202 −0
Original line number Diff line number Diff line 
/*

 * BCM47XX MTD partitioning

 *

 * Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>

 *

 * 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/kernel.h>

#include <linux/slab.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/partitions.h>

#include <asm/mach-bcm47xx/nvram.h>



/* 10 parts were found on sflash on Netgear WNDR4500 */

#define BCM47XXPART_MAX_PARTS		12



/*

 * Amount of bytes we read when analyzing each block of flash memory.

 * Set it big enough to allow detecting partition and reading important data.

 */

#define BCM47XXPART_BYTES_TO_READ	0x404



/* Magics */

#define BOARD_DATA_MAGIC		0x5246504D	/* MPFR */

#define POT_MAGIC1			0x54544f50	/* POTT */

#define POT_MAGIC2			0x504f		/* OP */

#define ML_MAGIC1			0x39685a42

#define ML_MAGIC2			0x26594131

#define TRX_MAGIC			0x30524448



struct trx_header {

	uint32_t magic;

	uint32_t length;

	uint32_t crc32;

	uint16_t flags;

	uint16_t version;

	uint32_t offset[3];

} __packed;



static void bcm47xxpart_add_part(struct mtd_partition *part, char *name,

				 u64 offset, uint32_t mask_flags)

{

	part->name = name;

	part->offset = offset;

	part->mask_flags = mask_flags;

}



static int bcm47xxpart_parse(struct mtd_info *master,

			     struct mtd_partition **pparts,

			     struct mtd_part_parser_data *data)

{

	struct mtd_partition *parts;

	uint8_t i, curr_part = 0;

	uint32_t *buf;

	size_t bytes_read;

	uint32_t offset;

	uint32_t blocksize = 0x10000;

	struct trx_header *trx;



	/* Alloc */

	parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,

			GFP_KERNEL);

	buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);



	/* Parse block by block looking for magics */

	for (offset = 0; offset <= master->size - blocksize;

	     offset += blocksize) {

		/* Nothing more in higher memory */

		if (offset >= 0x2000000)

			break;



		if (curr_part > BCM47XXPART_MAX_PARTS) {

			pr_warn("Reached maximum number of partitions, scanning stopped!\n");

			break;

		}



		/* Read beginning of the block */

		if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,

			     &bytes_read, (uint8_t *)buf) < 0) {

			pr_err("mtd_read error while parsing (offset: 0x%X)!\n",

			       offset);

			continue;

		}



		/* CFE has small NVRAM at 0x400 */

		if (buf[0x400 / 4] == NVRAM_HEADER) {

			bcm47xxpart_add_part(&parts[curr_part++], "boot",

					     offset, MTD_WRITEABLE);

			continue;

		}



		/* Standard NVRAM */

		if (buf[0x000 / 4] == NVRAM_HEADER) {

			bcm47xxpart_add_part(&parts[curr_part++], "nvram",

					     offset, 0);

			continue;

		}



		/*

		 * board_data starts with board_id which differs across boards,

		 * but we can use 'MPFR' (hopefully) magic at 0x100

		 */

		if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {

			bcm47xxpart_add_part(&parts[curr_part++], "board_data",

					     offset, MTD_WRITEABLE);

			continue;

		}



		/* POT(TOP) */

		if (buf[0x000 / 4] == POT_MAGIC1 &&

		    (buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {

			bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,

					     MTD_WRITEABLE);

			continue;

		}



		/* ML */

		if (buf[0x010 / 4] == ML_MAGIC1 &&

		    buf[0x014 / 4] == ML_MAGIC2) {

			bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,

					     MTD_WRITEABLE);

			continue;

		}



		/* TRX */

		if (buf[0x000 / 4] == TRX_MAGIC) {

			trx = (struct trx_header *)buf;



			i = 0;

			/* We have LZMA loader if offset[2] points to sth */

			if (trx->offset[2]) {

				bcm47xxpart_add_part(&parts[curr_part++],

						     "loader",

						     offset + trx->offset[i],

						     0);

				i++;

			}



			bcm47xxpart_add_part(&parts[curr_part++], "linux",

					     offset + trx->offset[i], 0);

			i++;



			/*

			 * Pure rootfs size is known and can be calculated as:

			 * trx->length - trx->offset[i]. We don't fill it as

			 * we want to have jffs2 (overlay) in the same mtd.

			 */

			bcm47xxpart_add_part(&parts[curr_part++], "rootfs",

					     offset + trx->offset[i], 0);

			i++;



			/*

			 * We have whole TRX scanned, skip to the next part. Use

			 * roundown (not roundup), as the loop will increase

			 * offset in next step.

			 */

			offset = rounddown(offset + trx->length, blocksize);

			continue;

		}

	}

	kfree(buf);



	/*

	 * Assume that partitions end at the beginning of the one they are

	 * followed by.

	 */

	for (i = 0; i < curr_part - 1; i++)

		parts[i].size = parts[i + 1].offset - parts[i].offset;

	if (curr_part > 0)

		parts[curr_part - 1].size =

				master->size - parts[curr_part - 1].offset;



	*pparts = parts;

	return curr_part;

};



static struct mtd_part_parser bcm47xxpart_mtd_parser = {

	.owner = THIS_MODULE,

	.parse_fn = bcm47xxpart_parse,

	.name = "bcm47xxpart",

};



static int __init bcm47xxpart_init(void)

{

	return register_mtd_parser(&bcm47xxpart_mtd_parser);

}



static void __exit bcm47xxpart_exit(void)

{

	deregister_mtd_parser(&bcm47xxpart_mtd_parser);

}



module_init(bcm47xxpart_init);

module_exit(bcm47xxpart_exit);



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");