[linux-2.6-block.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>

#include <uapi/linux/magic.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 SHSQ_MAGIC			0x71736873	/* shsq (weird ZTE H218N endianness) */
#define UBI_EC_MAGIC			0x23494255	/* UBI# */

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, const char *name,
				 u64 offset, uint32_t mask_flags)
{
	part->name = name;
	part->offset = offset;
	part->mask_flags = mask_flags;
}

static const char *bcm47xxpart_trx_data_part_name(struct mtd_info *master,
						  size_t offset)
{
	uint32_t buf;
	size_t bytes_read;

	if (mtd_read(master, offset, sizeof(buf), &bytes_read,
		     (uint8_t *)&buf) < 0) {
		pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
			offset);
		goto out_default;
	}

	if (buf == UBI_EC_MAGIC)
		return "ubi";

out_default:
	return "rootfs";
}

static int bcm47xxpart_parse(struct mtd_info *master,
			     const 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, };

	/*
	 * Some really old flashes (like AT45DB*) had smaller erasesize-s, but
	 * partitions were aligned to at least 0x1000 anyway.
	 */
	if (blocksize < 0x1000)
		blocksize = 0x1000;

	/* 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]) {
				const char *name;

				name = bcm47xxpart_trx_data_part_name(master, offset + trx->offset[i]);
				bcm47xxpart_add_part(&parts[curr_part++],
						     name,
						     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 (le32_to_cpu(buf[0x000 / 4]) == SQUASHFS_MAGIC ||
		    buf[0x000 / 4] == SHSQ_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 = {
	.parse_fn = bcm47xxpart_parse,
	.name = "bcm47xxpart",
};
module_mtd_part_parser(bcm47xxpart_mtd_parser);

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
0b56d2d4 RM	18	#include <uapi/linux/magic.h>
0b56d2d4 RM	19
59af5c7a RM	20	/*
	21	* NAND flash on Netgear R6250 was verified to contain 15 partitions.
	22	* This will result in allocating too big array for some old devices, but the
	23	* memory will be freed soon anyway (see mtd_device_parse_register).
	24	*/
	25	#define BCM47XXPART_MAX_PARTS 20
3cf7f131	26
5ca1088f RM	27	/*
	28	* Amount of bytes we read when analyzing each block of flash memory.
	29	* Set it big enough to allow detecting partition and reading important data.
	30	*/
4f8aaf72	31	#define BCM47XXPART_BYTES_TO_READ 0x4e8
5ca1088f	32
3cf7f131 RM	33	/* Magics */
3cf7f131 RM	34	#define BOARD_DATA_MAGIC 0x5246504D /* MPFR */
f0501e81	35	#define BOARD_DATA_MAGIC2 0xBD0D0BBD
4f8aaf72	36	#define CFE_MAGIC 0x43464531 /* 1EFC */
33094c73	37	#define FACTORY_MAGIC 0x59544346 /* FCTY */
9e3afa5f	38	#define NVRAM_HEADER 0x48534C46 /* FLSH */
3cf7f131 RM	39	#define POT_MAGIC1 0x54544f50 /* POTT */
	40	#define POT_MAGIC2 0x504f /* OP */
	41	#define ML_MAGIC1 0x39685a42
	42	#define ML_MAGIC2 0x26594131
	43	#define TRX_MAGIC 0x30524448
0b56d2d4	44	#define SHSQ_MAGIC 0x71736873 /* shsq (weird ZTE H218N endianness) */
bd10c26a	45	#define UBI_EC_MAGIC 0x23494255 /* UBI# */
3cf7f131 RM	46
	47	struct trx_header {
	48	uint32_t magic;
	49	uint32_t length;
	50	uint32_t crc32;
	51	uint16_t flags;
	52	uint16_t version;
	53	uint32_t offset[3];
	54	} __packed;
	55
bd10c26a	56	static void bcm47xxpart_add_part(struct mtd_partition part, const char name,
3cf7f131 RM	57	u64 offset, uint32_t mask_flags)
	58	{
	59	part->name = name;
	60	part->offset = offset;
	61	part->mask_flags = mask_flags;
	62	}
	63
bd10c26a RM	64	static const char bcm47xxpart_trx_data_part_name(struct mtd_info master,
	65	size_t offset)
	66	{
	67	uint32_t buf;
	68	size_t bytes_read;
	69
	70	if (mtd_read(master, offset, sizeof(buf), &bytes_read,
	71	(uint8_t *)&buf) < 0) {
	72	pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
	73	offset);
	74	goto out_default;
	75	}
	76
	77	if (buf == UBI_EC_MAGIC)
	78	return "ubi";
	79
	80	out_default:
	81	return "rootfs";
	82	}
	83
3cf7f131	84	static int bcm47xxpart_parse(struct mtd_info *master,
b9adf469	85	const struct mtd_partition **pparts,
3cf7f131 RM	86	struct mtd_part_parser_data *data)
	87	{
	88	struct mtd_partition *parts;
	89	uint8_t i, curr_part = 0;
	90	uint32_t *buf;
	91	size_t bytes_read;
	92	uint32_t offset;
25bad1d3	93	uint32_t blocksize = master->erasesize;
3cf7f131	94	struct trx_header *trx;
396afe55 RM	95	int trx_part = -1;
396afe55 RM	96	int last_trx_part = -1;
91d542f4	97	int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, };
3cf7f131	98
16bd87b3 RM	99	/*
	100	* Some really old flashes (like AT45DB*) had smaller erasesize-s, but
	101	* partitions were aligned to at least 0x1000 anyway.
	102	*/
	103	if (blocksize < 0x1000)
	104	blocksize = 0x1000;
3cf7f131 RM	105
	106	/* Alloc */
	107	parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
	108	GFP_KERNEL);
99b1d188 HM	109	if (!parts)
	110	return -ENOMEM;
	111
5ca1088f	112	buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
99b1d188 HM	113	if (!buf) {
	114	kfree(parts);
	115	return -ENOMEM;
	116	}
3cf7f131 RM	117
	118	/* Parse block by block looking for magics */
	119	for (offset = 0; offset <= master->size - blocksize;
	120	offset += blocksize) {
	121	/* Nothing more in higher memory */
	122	if (offset >= 0x2000000)
	123	break;
	124
00b79860	125	if (curr_part >= BCM47XXPART_MAX_PARTS) {
3cf7f131 RM	126	pr_warn("Reached maximum number of partitions, scanning stopped!\n");
	127	break;
	128	}
	129
	130	/* Read beginning of the block */
5ca1088f	131	if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
3cf7f131 RM	132	&bytes_read, (uint8_t *)buf) < 0) {
	133	pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
	134	offset);
	135	continue;
	136	}
	137
4f8aaf72 RM	138	/* Magic or small NVRAM at 0x400 */
	139	if ((buf[0x4e0 / 4] == CFE_MAGIC && buf[0x4e4 / 4] == CFE_MAGIC) \|\|
	140	(buf[0x400 / 4] == NVRAM_HEADER)) {
3cf7f131 RM	141	bcm47xxpart_add_part(&parts[curr_part++], "boot",
	142	offset, MTD_WRITEABLE);
	143	continue;
	144	}
	145
3cf7f131 RM	146	/*
	147	* board_data starts with board_id which differs across boards,
	148	* but we can use 'MPFR' (hopefully) magic at 0x100
	149	*/
	150	if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
	151	bcm47xxpart_add_part(&parts[curr_part++], "board_data",
	152	offset, MTD_WRITEABLE);
	153	continue;
	154	}
	155
33094c73 RM	156	/* Found on Huawei E970 */
	157	if (buf[0x000 / 4] == FACTORY_MAGIC) {
	158	bcm47xxpart_add_part(&parts[curr_part++], "factory",
	159	offset, MTD_WRITEABLE);
	160	continue;
	161	}
	162
3cf7f131 RM	163	/* POT(TOP) */
	164	if (buf[0x000 / 4] == POT_MAGIC1 &&
	165	(buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
	166	bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
	167	MTD_WRITEABLE);
	168	continue;
	169	}
	170
	171	/* ML */
	172	if (buf[0x010 / 4] == ML_MAGIC1 &&
	173	buf[0x014 / 4] == ML_MAGIC2) {
	174	bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
	175	MTD_WRITEABLE);
	176	continue;
	177	}
	178
	179	/* TRX */
	180	if (buf[0x000 / 4] == TRX_MAGIC) {
108ebcd8 RM	181	if (BCM47XXPART_MAX_PARTS - curr_part < 4) {
	182	pr_warn("Not enough partitions left to register trx, scanning stopped!\n");
	183	break;
	184	}
	185
3cf7f131 RM	186	trx = (struct trx_header *)buf;
3cf7f131 RM	187
396afe55 RM	188	trx_part = curr_part;
	189	bcm47xxpart_add_part(&parts[curr_part++], "firmware",
	190	offset, 0);
	191
3cf7f131 RM	192	i = 0;
	193	/* We have LZMA loader if offset[2] points to sth */
	194	if (trx->offset[2]) {
	195	bcm47xxpart_add_part(&parts[curr_part++],
	196	"loader",
	197	offset + trx->offset[i],
	198	0);
	199	i++;
	200	}
	201
a1ff7d64 HM	202	if (trx->offset[i]) {
	203	bcm47xxpart_add_part(&parts[curr_part++],
	204	"linux",
	205	offset + trx->offset[i],
	206	0);
	207	i++;
	208	}
3cf7f131 RM	209
	210	/*
	211	* Pure rootfs size is known and can be calculated as:
	212	* trx->length - trx->offset[i]. We don't fill it as
	213	* we want to have jffs2 (overlay) in the same mtd.
	214	*/
a1ff7d64	215	if (trx->offset[i]) {
bd10c26a RM	216	const char *name;
	217
	218	name = bcm47xxpart_trx_data_part_name(master, offset + trx->offset[i]);
a1ff7d64	219	bcm47xxpart_add_part(&parts[curr_part++],
bd10c26a	220	name,
a1ff7d64 HM	221	offset + trx->offset[i],
	222	0);
	223	i++;
	224	}
3cf7f131	225
396afe55 RM	226	last_trx_part = curr_part - 1;
396afe55 RM	227
3cf7f131 RM	228	/*
	229	* We have whole TRX scanned, skip to the next part. Use
	230	* roundown (not roundup), as the loop will increase
	231	* offset in next step.
	232	*/
	233	offset = rounddown(offset + trx->length, blocksize);
	234	continue;
	235	}
020c6bcf RM	236
020c6bcf RM	237	/* Squashfs on devices not using TRX */
0b56d2d4 RM	238	if (le32_to_cpu(buf[0x000 / 4]) == SQUASHFS_MAGIC \|\|
0b56d2d4 RM	239	buf[0x000 / 4] == SHSQ_MAGIC) {
020c6bcf RM	240	bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
	241	offset, 0);
	242	continue;
024629fd RM	243	}
	244
	245	/*
	246	* New (ARM?) devices may have NVRAM in some middle block. Last
	247	* block will be checked later, so skip it.
	248	*/
	249	if (offset != master->size - blocksize &&
	250	buf[0x000 / 4] == NVRAM_HEADER) {
	251	bcm47xxpart_add_part(&parts[curr_part++], "nvram",
	252	offset, 0);
	253	continue;
020c6bcf	254	}
f0501e81 RM	255
	256	/* Read middle of the block */
	257	if (mtd_read(master, offset + 0x8000, 0x4,
	258	&bytes_read, (uint8_t *)buf) < 0) {
	259	pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
	260	offset);
	261	continue;
	262	}
	263
	264	/* Some devices (ex. WNDR3700v3) don't have a standard 'MPFR' */
	265	if (buf[0x000 / 4] == BOARD_DATA_MAGIC2) {
	266	bcm47xxpart_add_part(&parts[curr_part++], "board_data",
	267	offset, MTD_WRITEABLE);
	268	continue;
	269	}
3cf7f131	270	}
91d542f4 RM	271
	272	/* Look for NVRAM at the end of the last block. */
	273	for (i = 0; i < ARRAY_SIZE(possible_nvram_sizes); i++) {
00b79860	274	if (curr_part >= BCM47XXPART_MAX_PARTS) {
91d542f4 RM	275	pr_warn("Reached maximum number of partitions, scanning stopped!\n");
	276	break;
	277	}
	278
	279	offset = master->size - possible_nvram_sizes[i];
	280	if (mtd_read(master, offset, 0x4, &bytes_read,
	281	(uint8_t *)buf) < 0) {
	282	pr_err("mtd_read error while reading at offset 0x%X!\n",
	283	offset);
	284	continue;
	285	}
	286
	287	/* Standard NVRAM */
	288	if (buf[0] == NVRAM_HEADER) {
	289	bcm47xxpart_add_part(&parts[curr_part++], "nvram",
	290	master->size - blocksize, 0);
	291	break;
	292	}
	293	}
	294
3cf7f131 RM	295	kfree(buf);
	296
	297	/*
	298	* Assume that partitions end at the beginning of the one they are
	299	* followed by.
	300	*/
648bdbee RM	301	for (i = 0; i < curr_part; i++) {
	302	u64 next_part_offset = (i < curr_part - 1) ?
	303	parts[i + 1].offset : master->size;
	304
	305	parts[i].size = next_part_offset - parts[i].offset;
396afe55 RM	306	if (i == last_trx_part && trx_part >= 0)
	307	parts[trx_part].size = next_part_offset -
	308	parts[trx_part].offset;
648bdbee	309	}
3cf7f131 RM	310
	311	*pparts = parts;
	312	return curr_part;
	313	};
	314
	315	static struct mtd_part_parser bcm47xxpart_mtd_parser = {
3cf7f131 RM	316	.parse_fn = bcm47xxpart_parse,
	317	.name = "bcm47xxpart",
	318	};
b8f70bad	319	module_mtd_part_parser(bcm47xxpart_mtd_parser);
3cf7f131 RM	320
	321	MODULE_LICENSE("GPL");
	322	MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");