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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/mtd/parsers/bcm47xxpart.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/mtd/parsers/bcm47xxpart.c')
-rw-r--r-- | drivers/mtd/parsers/bcm47xxpart.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/drivers/mtd/parsers/bcm47xxpart.c b/drivers/mtd/parsers/bcm47xxpart.c new file mode 100644 index 000000000..13daf9bff --- /dev/null +++ b/drivers/mtd/parsers/bcm47xxpart.c @@ -0,0 +1,317 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * BCM47XX MTD partitioning + * + * Copyright © 2012 Rafał Miłecki <zajec5@gmail.com> + */ + +#include <linux/bcm47xx_nvram.h> +#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) */ + +static const char * const trx_types[] = { "trx", NULL }; + +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; +} + +/** + * bcm47xxpart_bootpartition - gets index of TRX partition used by bootloader + * + * Some devices may have more than one TRX partition. In such case one of them + * is the main one and another a failsafe one. Bootloader may fallback to the + * failsafe firmware if it detects corruption of the main image. + * + * This function provides info about currently used TRX partition. It's the one + * containing kernel started by the bootloader. + */ +static int bcm47xxpart_bootpartition(void) +{ + char buf[4]; + int bootpartition; + + /* Check CFE environment variable */ + if (bcm47xx_nvram_getenv("bootpartition", buf, sizeof(buf)) > 0) { + if (!kstrtoint(buf, 0, &bootpartition)) + return bootpartition; + } + + return 0; +} + +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; + int trx_parts[2]; /* Array with indexes of TRX partitions */ + int trx_num = 0; /* Number of found TRX partitions */ + int possible_nvram_sizes[] = { 0x8000, 0xF000, 0x10000, }; + int err; + + /* + * 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 = kcalloc(BCM47XXPART_MAX_PARTS, sizeof(struct mtd_partition), + 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 on BCM47XX (MIPS) */ + if (IS_ENABLED(CONFIG_BCM47XX) && 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 */ + err = mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ, + &bytes_read, (uint8_t *)buf); + if (err && !mtd_is_bitflip(err)) { + pr_err("mtd_read error while parsing (offset: 0x%X): %d\n", + offset, err); + 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) { + struct trx_header *trx; + uint32_t last_subpart; + uint32_t trx_size; + + if (trx_num >= ARRAY_SIZE(trx_parts)) + pr_warn("No enough space to store another TRX found at 0x%X\n", + offset); + else + trx_parts[trx_num++] = curr_part; + bcm47xxpart_add_part(&parts[curr_part++], "firmware", + offset, 0); + + /* + * Try to find TRX size. The "length" field isn't fully + * reliable as it could be decreased to make CRC32 cover + * only part of TRX data. It's commonly used as checksum + * can't cover e.g. ever-changing rootfs partition. + * Use offsets as helpers for assuming min TRX size. + */ + trx = (struct trx_header *)buf; + last_subpart = max3(trx->offset[0], trx->offset[1], + trx->offset[2]); + trx_size = max(trx->length, last_subpart + blocksize); + + /* + * Skip the TRX data. Decrease offset by block size as + * the next loop iteration will increase it. + */ + offset += roundup(trx_size, blocksize) - 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 */ + err = mtd_read(master, offset + (blocksize / 2), 0x4, &bytes_read, + (uint8_t *)buf); + if (err && !mtd_is_bitflip(err)) { + pr_err("mtd_read error while parsing (offset: 0x%X): %d\n", + offset + (blocksize / 2), err); + 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]; + err = mtd_read(master, offset, 0x4, &bytes_read, + (uint8_t *)buf); + if (err && !mtd_is_bitflip(err)) { + pr_err("mtd_read error while reading (offset 0x%X): %d\n", + offset, err); + 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 there was TRX parse it now */ + for (i = 0; i < trx_num; i++) { + struct mtd_partition *trx = &parts[trx_parts[i]]; + + if (i == bcm47xxpart_bootpartition()) + trx->types = trx_types; + else + trx->name = "failsafe"; + } + + *pparts = parts; + return curr_part; +}; + +static const struct of_device_id bcm47xxpart_of_match_table[] = { + { .compatible = "brcm,bcm947xx-cfe-partitions" }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm47xxpart_of_match_table); + +static struct mtd_part_parser bcm47xxpart_mtd_parser = { + .parse_fn = bcm47xxpart_parse, + .name = "bcm47xxpart", + .of_match_table = bcm47xxpart_of_match_table, +}; +module_mtd_part_parser(bcm47xxpart_mtd_parser); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories"); |