[deliverable/linux.git] / drivers / mtd / bcm47xxpart.c

/*
 * 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>

/*
 * NAND flash on Netgear R6250 was verified to contain 15 partitions.
 * This will result in allocating too big array for some old devices, but the
 * memory will be freed soon anyway (see mtd_device_parse_register).
 */
#define BCM47XXPART_MAX_PARTS		20

/*
 * 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	0x4e8

/* Magics */
#define BOARD_DATA_MAGIC		0x5246504D	/* MPFR */
#define BOARD_DATA_MAGIC2		0xBD0D0BBD
#define CFE_MAGIC			0x43464531	/* 1EFC */
#define FACTORY_MAGIC			0x59544346	/* FCTY */
#define NVRAM_HEADER			0x48534C46	/* FLSH */
#define POT_MAGIC1			0x54544f50	/* POTT */
#define POT_MAGIC2			0x504f		/* OP */
#define ML_MAGIC1			0x39685a42
#define ML_MAGIC2			0x26594131
#define TRX_MAGIC			0x30524448
#define SQSH_MAGIC			0x71736873	/* shsq */

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 = master->erasesize;
	struct trx_header *trx;
	int trx_part = -1;
	int last_trx_part = -1;
	int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };

	if (blocksize <= 0x10000)
		blocksize = 0x10000;

	/* Alloc */
	parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
			GFP_KERNEL);
	if (!parts)
		return -ENOMEM;

	buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
	if (!buf) {
		kfree(parts);
		return -ENOMEM;
	}

	/* 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;
		}

		/* Magic or small NVRAM at 0x400 */
		if ((buf[0x4e0 / 4] == CFE_MAGIC && buf[0x4e4 / 4] == CFE_MAGIC) ||
		    (buf[0x400 / 4] == NVRAM_HEADER)) {
			bcm47xxpart_add_part(&parts[curr_part++], "boot",
					     offset, MTD_WRITEABLE);
			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;
		}

		/* Found on Huawei E970 */
		if (buf[0x000 / 4] == FACTORY_MAGIC) {
			bcm47xxpart_add_part(&parts[curr_part++], "factory",
					     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) {
			if (BCM47XXPART_MAX_PARTS - curr_part < 4) {
				pr_warn("Not enough partitions left to register trx, scanning stopped!\n");
				break;
			}

			trx = (struct trx_header *)buf;

			trx_part = curr_part;
			bcm47xxpart_add_part(&parts[curr_part++], "firmware",
					     offset, 0);

			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++;
			}

			if (trx->offset[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.
			 */
			if (trx->offset[i]) {
				bcm47xxpart_add_part(&parts[curr_part++],
						     "rootfs",
						     offset + trx->offset[i],
						     0);
				i++;
			}

			last_trx_part = curr_part - 1;

			/*
			 * 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;
		}

		/* Squashfs on devices not using TRX */
		if (buf[0x000 / 4] == SQSH_MAGIC) {
			bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
					     offset, 0);
			continue;
		}

		/*
		 * New (ARM?) devices may have NVRAM in some middle block. Last
		 * block will be checked later, so skip it.
		 */
		if (offset != master->size - blocksize &&
		    buf[0x000 / 4] == NVRAM_HEADER) {
			bcm47xxpart_add_part(&parts[curr_part++], "nvram",
					     offset, 0);
			continue;
		}

		/* Read middle of the block */
		if (mtd_read(master, offset + 0x8000, 0x4,
			     &bytes_read, (uint8_t *)buf) < 0) {
			pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
			       offset);
			continue;
		}

		/* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */
		if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) {
			bcm47xxpart_add_part(&parts[curr_part++], "board_data",
					     offset, MTD_WRITEABLE);
			continue;
		}
	}

	/* Look for NVRAM at the end of the last block. */
	for (i = 0; i < ARRAY_SIZE(possible_nvram_sizes); i++) {
		if (curr_part >= BCM47XXPART_MAX_PARTS) {
			pr_warn("Reached maximum number of partitions, scanning stopped!\n");
			break;
		}

		offset = master->size - possible_nvram_sizes[i];
		if (mtd_read(master, offset, 0x4, &bytes_read,
			     (uint8_t *)buf) < 0) {
			pr_err("mtd_read error while reading at offset 0x%X!\n",
			       offset);
			continue;
		}

		/* Standard NVRAM */
		if (buf[0] == NVRAM_HEADER) {
			bcm47xxpart_add_part(&parts[curr_part++], "nvram",
					     master->size - blocksize, 0);
			break;
		}
	}

	kfree(buf);

	/*
	 * Assume that partitions end at the beginning of the one they are
	 * followed by.
	 */
	for (i = 0; i < curr_part; i++) {
		u64 next_part_offset = (i < curr_part - 1) ?
				       parts[i + 1].offset : master->size;

		parts[i].size = next_part_offset - parts[i].offset;
		if (i == last_trx_part && trx_part >= 0)
			parts[trx_part].size = next_part_offset -
					       parts[trx_part].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)
{
	register_mtd_parser(&bcm47xxpart_mtd_parser);
	return 0;
}

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");
Commit	Line	Data
3cf7f131 RM	1	/*
	2	* BCM47XX MTD partitioning
	3	*
	4	* Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/slab.h>
	15	#include <linux/mtd/mtd.h>
	16	#include <linux/mtd/partitions.h>
3cf7f131	17
59af5c7a RM	18	/*
	19	* NAND flash on Netgear R6250 was verified to contain 15 partitions.
	20	* This will result in allocating too big array for some old devices, but the
	21	* memory will be freed soon anyway (see mtd_device_parse_register).
	22	*/
	23	#define BCM47XXPART_MAX_PARTS 20
3cf7f131	24
5ca1088f RM	25	/*
	26	* Amount of bytes we read when analyzing each block of flash memory.
	27	* Set it big enough to allow detecting partition and reading important data.
	28	*/
4f8aaf72	29	#define BCM47XXPART_BYTES_TO_READ 0x4e8
5ca1088f	30
3cf7f131 RM	31	/* Magics */
3cf7f131 RM	32	#define BOARD_DATA_MAGIC 0x5246504D /* MPFR */
f0501e81	33	#define BOARD_DATA_MAGIC2 0xBD0D0BBD
4f8aaf72	34	#define CFE_MAGIC 0x43464531 /* 1EFC */
33094c73	35	#define FACTORY_MAGIC 0x59544346 /* FCTY */
9e3afa5f	36	#define NVRAM_HEADER 0x48534C46 /* FLSH */
3cf7f131 RM	37	#define POT_MAGIC1 0x54544f50 /* POTT */
	38	#define POT_MAGIC2 0x504f /* OP */
	39	#define ML_MAGIC1 0x39685a42
	40	#define ML_MAGIC2 0x26594131
	41	#define TRX_MAGIC 0x30524448
020c6bcf	42	#define SQSH_MAGIC 0x71736873 /* shsq */
3cf7f131 RM	43
	44	struct trx_header {
	45	uint32_t magic;
	46	uint32_t length;
	47	uint32_t crc32;
	48	uint16_t flags;
	49	uint16_t version;
	50	uint32_t offset[3];
	51	} __packed;
	52
	53	static void bcm47xxpart_add_part(struct mtd_partition part, char name,
	54	u64 offset, uint32_t mask_flags)
	55	{
	56	part->name = name;
	57	part->offset = offset;
	58	part->mask_flags = mask_flags;
	59	}
	60
	61	static int bcm47xxpart_parse(struct mtd_info *master,
	62	struct mtd_partition **pparts,
	63	struct mtd_part_parser_data *data)
	64	{
	65	struct mtd_partition *parts;
	66	uint8_t i, curr_part = 0;
	67	uint32_t *buf;
	68	size_t bytes_read;
	69	uint32_t offset;
25bad1d3	70	uint32_t blocksize = master->erasesize;
3cf7f131	71	struct trx_header *trx;
396afe55 RM	72	int trx_part = -1;
396afe55 RM	73	int last_trx_part = -1;
91d542f4	74	int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
3cf7f131	75
25bad1d3 HM	76	if (blocksize <= 0x10000)
25bad1d3 HM	77	blocksize = 0x10000;
3cf7f131 RM	78
	79	/* Alloc */
	80	parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
	81	GFP_KERNEL);
99b1d188 HM	82	if (!parts)
	83	return -ENOMEM;
	84
5ca1088f	85	buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
99b1d188 HM	86	if (!buf) {
	87	kfree(parts);
	88	return -ENOMEM;
	89	}
3cf7f131 RM	90
	91	/* Parse block by block looking for magics */
	92	for (offset = 0; offset <= master->size - blocksize;
	93	offset += blocksize) {
	94	/* Nothing more in higher memory */
	95	if (offset >= 0x2000000)
	96	break;
	97
00b79860	98	if (curr_part >= BCM47XXPART_MAX_PARTS) {
3cf7f131 RM	99	pr_warn("Reached maximum number of partitions, scanning stopped!\n");
	100	break;
	101	}
	102
	103	/* Read beginning of the block */
5ca1088f	104	if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
3cf7f131 RM	105	&bytes_read, (uint8_t *)buf) < 0) {
	106	pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
	107	offset);
	108	continue;
	109	}
	110
4f8aaf72 RM	111	/* Magic or small NVRAM at 0x400 */
	112	if ((buf[0x4e0 / 4] == CFE_MAGIC && buf[0x4e4 / 4] == CFE_MAGIC) \|\|
	113	(buf[0x400 / 4] == NVRAM_HEADER)) {
3cf7f131 RM	114	bcm47xxpart_add_part(&parts[curr_part++], "boot",
	115	offset, MTD_WRITEABLE);
	116	continue;
	117	}
	118
3cf7f131 RM	119	/*
	120	* board_data starts with board_id which differs across boards,
	121	* but we can use 'MPFR' (hopefully) magic at 0x100
	122	*/
	123	if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
	124	bcm47xxpart_add_part(&parts[curr_part++], "board_data",
	125	offset, MTD_WRITEABLE);
	126	continue;
	127	}
	128
33094c73 RM	129	/* Found on Huawei E970 */
	130	if (buf[0x000 / 4] == FACTORY_MAGIC) {
	131	bcm47xxpart_add_part(&parts[curr_part++], "factory",
	132	offset, MTD_WRITEABLE);
	133	continue;
	134	}
	135
3cf7f131 RM	136	/* POT(TOP) */
	137	if (buf[0x000 / 4] == POT_MAGIC1 &&
	138	(buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
	139	bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
	140	MTD_WRITEABLE);
	141	continue;
	142	}
	143
	144	/* ML */
	145	if (buf[0x010 / 4] == ML_MAGIC1 &&
	146	buf[0x014 / 4] == ML_MAGIC2) {
	147	bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
	148	MTD_WRITEABLE);
	149	continue;
	150	}
	151
	152	/* TRX */
	153	if (buf[0x000 / 4] == TRX_MAGIC) {
108ebcd8 RM	154	if (BCM47XXPART_MAX_PARTS - curr_part < 4) {
	155	pr_warn("Not enough partitions left to register trx, scanning stopped!\n");
	156	break;
	157	}
	158
3cf7f131 RM	159	trx = (struct trx_header *)buf;
3cf7f131 RM	160
396afe55 RM	161	trx_part = curr_part;
	162	bcm47xxpart_add_part(&parts[curr_part++], "firmware",
	163	offset, 0);
	164
3cf7f131 RM	165	i = 0;
	166	/* We have LZMA loader if offset[2] points to sth */
	167	if (trx->offset[2]) {
	168	bcm47xxpart_add_part(&parts[curr_part++],
	169	"loader",
	170	offset + trx->offset[i],
	171	0);
	172	i++;
	173	}
	174
a1ff7d64 HM	175	if (trx->offset[i]) {
	176	bcm47xxpart_add_part(&parts[curr_part++],
	177	"linux",
	178	offset + trx->offset[i],
	179	0);
	180	i++;
	181	}
3cf7f131 RM	182
	183	/*
	184	* Pure rootfs size is known and can be calculated as:
	185	* trx->length - trx->offset[i]. We don't fill it as
	186	* we want to have jffs2 (overlay) in the same mtd.
	187	*/
a1ff7d64 HM	188	if (trx->offset[i]) {
	189	bcm47xxpart_add_part(&parts[curr_part++],
	190	"rootfs",
	191	offset + trx->offset[i],
	192	0);
	193	i++;
	194	}
3cf7f131	195
396afe55 RM	196	last_trx_part = curr_part - 1;
396afe55 RM	197
3cf7f131 RM	198	/*
	199	* We have whole TRX scanned, skip to the next part. Use
	200	* roundown (not roundup), as the loop will increase
	201	* offset in next step.
	202	*/
	203	offset = rounddown(offset + trx->length, blocksize);
	204	continue;
	205	}
020c6bcf RM	206
	207	/* Squashfs on devices not using TRX */
	208	if (buf[0x000 / 4] == SQSH_MAGIC) {
	209	bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
	210	offset, 0);
	211	continue;
024629fd RM	212	}
	213
	214	/*
	215	* New (ARM?) devices may have NVRAM in some middle block. Last
	216	* block will be checked later, so skip it.
	217	*/
	218	if (offset != master->size - blocksize &&
	219	buf[0x000 / 4] == NVRAM_HEADER) {
	220	bcm47xxpart_add_part(&parts[curr_part++], "nvram",
	221	offset, 0);
	222	continue;
020c6bcf	223	}
f0501e81 RM	224
	225	/* Read middle of the block */
	226	if (mtd_read(master, offset + 0x8000, 0x4,
	227	&bytes_read, (uint8_t *)buf) < 0) {
	228	pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
	229	offset);
	230	continue;
	231	}
	232
	233	/* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */
	234	if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) {
	235	bcm47xxpart_add_part(&parts[curr_part++], "board_data",
	236	offset, MTD_WRITEABLE);
	237	continue;
	238	}
3cf7f131	239	}
91d542f4 RM	240
	241	/* Look for NVRAM at the end of the last block. */
	242	for (i = 0; i < ARRAY_SIZE(possible_nvram_sizes); i++) {
00b79860	243	if (curr_part >= BCM47XXPART_MAX_PARTS) {
91d542f4 RM	244	pr_warn("Reached maximum number of partitions, scanning stopped!\n");
	245	break;
	246	}
	247
	248	offset = master->size - possible_nvram_sizes[i];
	249	if (mtd_read(master, offset, 0x4, &bytes_read,
	250	(uint8_t *)buf) < 0) {
	251	pr_err("mtd_read error while reading at offset 0x%X!\n",
	252	offset);
	253	continue;
	254	}
	255
	256	/* Standard NVRAM */
	257	if (buf[0] == NVRAM_HEADER) {
	258	bcm47xxpart_add_part(&parts[curr_part++], "nvram",
	259	master->size - blocksize, 0);
	260	break;
	261	}
	262	}
	263
3cf7f131 RM	264	kfree(buf);
	265
	266	/*
	267	* Assume that partitions end at the beginning of the one they are
	268	* followed by.
	269	*/
648bdbee RM	270	for (i = 0; i < curr_part; i++) {
	271	u64 next_part_offset = (i < curr_part - 1) ?
	272	parts[i + 1].offset : master->size;
	273
	274	parts[i].size = next_part_offset - parts[i].offset;
396afe55 RM	275	if (i == last_trx_part && trx_part >= 0)
	276	parts[trx_part].size = next_part_offset -
	277	parts[trx_part].offset;
648bdbee	278	}
3cf7f131 RM	279
	280	*pparts = parts;
	281	return curr_part;
	282	};
	283
	284	static struct mtd_part_parser bcm47xxpart_mtd_parser = {
	285	.owner = THIS_MODULE,
	286	.parse_fn = bcm47xxpart_parse,
	287	.name = "bcm47xxpart",
	288	};
	289
	290	static int __init bcm47xxpart_init(void)
	291	{
6e14a61d AL	292	register_mtd_parser(&bcm47xxpart_mtd_parser);
6e14a61d AL	293	return 0;
3cf7f131 RM	294	}
	295
	296	static void __exit bcm47xxpart_exit(void)
	297	{
	298	deregister_mtd_parser(&bcm47xxpart_mtd_parser);
	299	}
	300
	301	module_init(bcm47xxpart_init);
	302	module_exit(bcm47xxpart_exit);
	303
	304	MODULE_LICENSE("GPL");
	305	MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");