| /* |
| * 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/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) */ |
| #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; |
| int err; |
| |
| err = mtd_read(master, offset, sizeof(buf), &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); |
| goto out_default; |
| } |
| |
| if (buf == UBI_EC_MAGIC) |
| return "ubi"; |
| |
| out_default: |
| return "rootfs"; |
| } |
| |
| static int bcm47xxpart_parse_trx(struct mtd_info *master, |
| struct mtd_partition *trx, |
| struct mtd_partition *parts, |
| size_t parts_len) |
| { |
| struct trx_header header; |
| size_t bytes_read; |
| int curr_part = 0; |
| int i, err; |
| |
| if (parts_len < 3) { |
| pr_warn("No enough space to add TRX partitions!\n"); |
| return -ENOMEM; |
| } |
| |
| err = mtd_read(master, trx->offset, sizeof(header), &bytes_read, |
| (uint8_t *)&header); |
| if (err && !mtd_is_bitflip(err)) { |
| pr_err("mtd_read error while reading TRX header: %d\n", err); |
| return err; |
| } |
| |
| i = 0; |
| |
| /* We have LZMA loader if offset[2] points to sth */ |
| if (header.offset[2]) { |
| bcm47xxpart_add_part(&parts[curr_part++], "loader", |
| trx->offset + header.offset[i], 0); |
| i++; |
| } |
| |
| if (header.offset[i]) { |
| bcm47xxpart_add_part(&parts[curr_part++], "linux", |
| trx->offset + header.offset[i], 0); |
| i++; |
| } |
| |
| if (header.offset[i]) { |
| size_t offset = trx->offset + header.offset[i]; |
| const char *name = bcm47xxpart_trx_data_part_name(master, |
| offset); |
| |
| bcm47xxpart_add_part(&parts[curr_part++], name, offset, 0); |
| i++; |
| } |
| |
| /* |
| * Assume that every partition ends at the beginning of the one it is |
| * followed by. |
| */ |
| for (i = 0; i < curr_part; i++) { |
| u64 next_part_offset = (i < curr_part - 1) ? |
| parts[i + 1].offset : |
| trx->offset + trx->size; |
| |
| parts[i].size = next_part_offset - parts[i].offset; |
| } |
| |
| return curr_part; |
| } |
| |
| /** |
| * 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 = 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 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; |
| |
| 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); |
| |
| /* Jump to the end of TRX */ |
| trx = (struct trx_header *)buf; |
| offset = roundup(offset + trx->length, blocksize); |
| /* Next loop iteration will increase the offset */ |
| offset -= 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 + 0x8000, 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, 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()) { |
| int num_parts; |
| |
| num_parts = bcm47xxpart_parse_trx(master, trx, |
| parts + curr_part, |
| BCM47XXPART_MAX_PARTS - curr_part); |
| if (num_parts > 0) |
| curr_part += num_parts; |
| } else { |
| trx->name = "failsafe"; |
| } |
| } |
| |
| *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"); |