| /* |
| * 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 <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 FACTORY_MAGIC 0x59544346 /* FCTY */ |
| #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; |
| } |
| |
| /* CFE has small NVRAM at 0x400 */ |
| if (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) { |
| 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++; |
| } |
| |
| 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++; |
| |
| 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; |
| } |
| } |
| |
| /* 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"); |