| Rafał Miłecki | 99352af | 2017-06-21 08:26:47 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Parser for TRX format partitions |
| 3 | * |
| 4 | * Copyright (C) 2012 - 2017 Rafał Miłecki <rafal@milecki.pl> |
| 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/slab.h> |
| 14 | #include <linux/mtd/mtd.h> |
| 15 | #include <linux/mtd/partitions.h> |
| 16 | |
| 17 | #define TRX_PARSER_MAX_PARTS 4 |
| 18 | |
| 19 | /* Magics */ |
| 20 | #define TRX_MAGIC 0x30524448 |
| 21 | #define UBI_EC_MAGIC 0x23494255 /* UBI# */ |
| 22 | |
| 23 | struct trx_header { |
| 24 | uint32_t magic; |
| 25 | uint32_t length; |
| 26 | uint32_t crc32; |
| 27 | uint16_t flags; |
| 28 | uint16_t version; |
| 29 | uint32_t offset[3]; |
| 30 | } __packed; |
| 31 | |
| 32 | static const char *parser_trx_data_part_name(struct mtd_info *master, |
| 33 | size_t offset) |
| 34 | { |
| 35 | uint32_t buf; |
| 36 | size_t bytes_read; |
| 37 | int err; |
| 38 | |
| 39 | err = mtd_read(master, offset, sizeof(buf), &bytes_read, |
| 40 | (uint8_t *)&buf); |
| 41 | if (err && !mtd_is_bitflip(err)) { |
| Rafał Miłecki | 58de51c | 2017-06-23 07:07:14 +0200 | [diff] [blame] | 42 | pr_err("mtd_read error while parsing (offset: 0x%zX): %d\n", |
| Rafał Miłecki | 99352af | 2017-06-21 08:26:47 +0200 | [diff] [blame] | 43 | offset, err); |
| 44 | goto out_default; |
| 45 | } |
| 46 | |
| 47 | if (buf == UBI_EC_MAGIC) |
| 48 | return "ubi"; |
| 49 | |
| 50 | out_default: |
| 51 | return "rootfs"; |
| 52 | } |
| 53 | |
| 54 | static int parser_trx_parse(struct mtd_info *mtd, |
| 55 | const struct mtd_partition **pparts, |
| 56 | struct mtd_part_parser_data *data) |
| 57 | { |
| 58 | struct mtd_partition *parts; |
| 59 | struct mtd_partition *part; |
| 60 | struct trx_header trx; |
| 61 | size_t bytes_read; |
| 62 | uint8_t curr_part = 0, i = 0; |
| 63 | int err; |
| 64 | |
| 65 | parts = kzalloc(sizeof(struct mtd_partition) * TRX_PARSER_MAX_PARTS, |
| 66 | GFP_KERNEL); |
| 67 | if (!parts) |
| 68 | return -ENOMEM; |
| 69 | |
| 70 | err = mtd_read(mtd, 0, sizeof(trx), &bytes_read, (uint8_t *)&trx); |
| 71 | if (err) { |
| 72 | pr_err("MTD reading error: %d\n", err); |
| 73 | kfree(parts); |
| 74 | return err; |
| 75 | } |
| 76 | |
| 77 | if (trx.magic != TRX_MAGIC) { |
| 78 | kfree(parts); |
| 79 | return -ENOENT; |
| 80 | } |
| 81 | |
| 82 | /* We have LZMA loader if there is address in offset[2] */ |
| 83 | if (trx.offset[2]) { |
| 84 | part = &parts[curr_part++]; |
| 85 | part->name = "loader"; |
| 86 | part->offset = trx.offset[i]; |
| 87 | i++; |
| 88 | } |
| 89 | |
| 90 | if (trx.offset[i]) { |
| 91 | part = &parts[curr_part++]; |
| 92 | part->name = "linux"; |
| 93 | part->offset = trx.offset[i]; |
| 94 | i++; |
| 95 | } |
| 96 | |
| 97 | if (trx.offset[i]) { |
| 98 | part = &parts[curr_part++]; |
| 99 | part->name = parser_trx_data_part_name(mtd, trx.offset[i]); |
| 100 | part->offset = trx.offset[i]; |
| 101 | i++; |
| 102 | } |
| 103 | |
| 104 | /* |
| 105 | * Assume that every partition ends at the beginning of the one it is |
| 106 | * followed by. |
| 107 | */ |
| 108 | for (i = 0; i < curr_part; i++) { |
| 109 | u64 next_part_offset = (i < curr_part - 1) ? |
| 110 | parts[i + 1].offset : mtd->size; |
| 111 | |
| 112 | parts[i].size = next_part_offset - parts[i].offset; |
| 113 | } |
| 114 | |
| 115 | *pparts = parts; |
| 116 | return i; |
| 117 | }; |
| 118 | |
| 119 | static struct mtd_part_parser mtd_parser_trx = { |
| 120 | .parse_fn = parser_trx_parse, |
| 121 | .name = "trx", |
| 122 | }; |
| 123 | module_mtd_part_parser(mtd_parser_trx); |
| 124 | |
| 125 | MODULE_LICENSE("GPL v2"); |
| 126 | MODULE_DESCRIPTION("Parser for TRX format partitions"); |