| 1 | /* |
| 2 | * Copyright (C) Gabor Juhos <juhosg@openwrt.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License version 2 as published |
| 6 | * by the Free Software Foundation. |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/list.h> |
| 15 | #include <linux/kmod.h> |
| 16 | #include <linux/root_dev.h> |
| 17 | |
| 18 | #include <linux/mtd/mtd.h> |
| 19 | #include <linux/mtd/partitions.h> |
| 20 | |
| 21 | #include <linux/byteorder/generic.h> |
| 22 | |
| 23 | #define PFX "trxsplit: " |
| 24 | |
| 25 | #define TRX_MAGIC 0x30524448 /* "HDR0" */ |
| 26 | #define TRX_VERSION 1 |
| 27 | #define TRX_MAX_LEN 0x3A0000 |
| 28 | #define TRX_NO_HEADER 0x1 /* do not write TRX header */ |
| 29 | #define TRX_GZ_FILES 0x2 /* contains individual gzip files */ |
| 30 | #define TRX_MAX_OFFSET 3 |
| 31 | #define TRX_MIN_KERNEL_SIZE (256 * 1024) |
| 32 | |
| 33 | struct trx_header { |
| 34 | u32 magic; /* "HDR0" */ |
| 35 | u32 len; /* Length of file including header */ |
| 36 | u32 crc32; /* 32-bit CRC from flag_version to end of file */ |
| 37 | u32 flag_version; /* 0:15 flags, 16:31 version */ |
| 38 | u32 offsets[TRX_MAX_OFFSET]; /* Offsets of partitions */ |
| 39 | }; |
| 40 | |
| 41 | #define TRX_ALIGN 0x1000 |
| 42 | |
| 43 | static int trx_nr_parts; |
| 44 | static unsigned long trx_offset; |
| 45 | static struct mtd_info *trx_mtd; |
| 46 | static struct mtd_partition trx_parts[TRX_MAX_OFFSET]; |
| 47 | static struct trx_header trx_hdr; |
| 48 | |
| 49 | static int trxsplit_refresh_partitions(struct mtd_info *mtd); |
| 50 | |
| 51 | static int trxsplit_checktrx(struct mtd_info *mtd, unsigned long offset) |
| 52 | { |
| 53 | size_t retlen; |
| 54 | int err; |
| 55 | |
| 56 | err = mtd->read(mtd, offset, sizeof(trx_hdr), &retlen, |
| 57 | (void *)&trx_hdr); |
| 58 | if (err) { |
| 59 | printk(KERN_ALERT PFX "unable to read from '%s'\n", mtd->name); |
| 60 | goto err_out; |
| 61 | } |
| 62 | |
| 63 | if (retlen != sizeof(trx_hdr)) { |
| 64 | printk(KERN_ALERT PFX "reading failed on '%s'\n", mtd->name); |
| 65 | goto err_out; |
| 66 | } |
| 67 | |
| 68 | trx_hdr.magic = le32_to_cpu(trx_hdr.magic); |
| 69 | trx_hdr.len = le32_to_cpu(trx_hdr.len); |
| 70 | trx_hdr.crc32 = le32_to_cpu(trx_hdr.crc32); |
| 71 | trx_hdr.flag_version = le32_to_cpu(trx_hdr.flag_version); |
| 72 | trx_hdr.offsets[0] = le32_to_cpu(trx_hdr.offsets[0]); |
| 73 | trx_hdr.offsets[1] = le32_to_cpu(trx_hdr.offsets[1]); |
| 74 | trx_hdr.offsets[2] = le32_to_cpu(trx_hdr.offsets[2]); |
| 75 | |
| 76 | /* sanity checks */ |
| 77 | if (trx_hdr.magic != TRX_MAGIC) |
| 78 | goto err_out; |
| 79 | |
| 80 | if (trx_hdr.len > mtd->size - offset) |
| 81 | goto err_out; |
| 82 | |
| 83 | /* TODO: add crc32 checking too? */ |
| 84 | |
| 85 | return 0; |
| 86 | |
| 87 | err_out: |
| 88 | return -1; |
| 89 | } |
| 90 | |
| 91 | static void trxsplit_findtrx(struct mtd_info *mtd) |
| 92 | { |
| 93 | unsigned long offset; |
| 94 | int err; |
| 95 | |
| 96 | printk(KERN_INFO PFX "searching TRX header in '%s'\n", mtd->name); |
| 97 | |
| 98 | err = 0; |
| 99 | for (offset = 0; offset < mtd->size; offset += TRX_ALIGN) { |
| 100 | err = trxsplit_checktrx(mtd, offset); |
| 101 | if (err == 0) |
| 102 | break; |
| 103 | } |
| 104 | |
| 105 | if (err) |
| 106 | return; |
| 107 | |
| 108 | printk(KERN_INFO PFX "TRX header found at 0x%lX\n", offset); |
| 109 | |
| 110 | trx_mtd = mtd; |
| 111 | trx_offset = offset; |
| 112 | } |
| 113 | |
| 114 | static void trxsplit_create_partitions(struct mtd_info *mtd) |
| 115 | { |
| 116 | struct mtd_partition *part = trx_parts; |
| 117 | int err; |
| 118 | int i; |
| 119 | |
| 120 | for (i = 0; i < TRX_MAX_OFFSET; i++) { |
| 121 | part = &trx_parts[i]; |
| 122 | if (trx_hdr.offsets[i] == 0) |
| 123 | continue; |
| 124 | part->offset = trx_offset + trx_hdr.offsets[i]; |
| 125 | trx_nr_parts++; |
| 126 | } |
| 127 | |
| 128 | for (i = 0; i < trx_nr_parts-1; i++) |
| 129 | trx_parts[i].size = trx_parts[i+1].offset - trx_parts[i].offset; |
| 130 | |
| 131 | trx_parts[i].size = mtd->size - trx_parts[i].offset; |
| 132 | |
| 133 | i = 0; |
| 134 | part = &trx_parts[i]; |
| 135 | if (part->size < TRX_MIN_KERNEL_SIZE) { |
| 136 | part->name = "loader"; |
| 137 | i++; |
| 138 | } |
| 139 | |
| 140 | part = &trx_parts[i]; |
| 141 | part->name = "kernel"; |
| 142 | i++; |
| 143 | |
| 144 | part = &trx_parts[i]; |
| 145 | part->name = "rootfs"; |
| 146 | |
| 147 | err = add_mtd_partitions(mtd, trx_parts, trx_nr_parts); |
| 148 | if (err) { |
| 149 | printk(KERN_ALERT PFX "adding TRX partitions failed\n"); |
| 150 | return; |
| 151 | } |
| 152 | |
| 153 | mtd->refresh_device = trxsplit_refresh_partitions; |
| 154 | } |
| 155 | |
| 156 | static int trxsplit_refresh_partitions(struct mtd_info *mtd) |
| 157 | { |
| 158 | printk(KERN_INFO PFX "refreshing TRX partitions in '%s' (%d,%d)\n", |
| 159 | mtd->name, MTD_BLOCK_MAJOR, mtd->index); |
| 160 | |
| 161 | /* remove old partitions */ |
| 162 | del_mtd_partitions(mtd); |
| 163 | |
| 164 | trxsplit_findtrx(mtd); |
| 165 | if (!trx_mtd) |
| 166 | goto err; |
| 167 | |
| 168 | trxsplit_create_partitions(trx_mtd); |
| 169 | return 1; |
| 170 | |
| 171 | err: |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | static void __init trxsplit_add_mtd(struct mtd_info *mtd) |
| 176 | { |
| 177 | if (mtd->type != MTD_NORFLASH) { |
| 178 | printk(KERN_INFO PFX "'%s' is not a NOR flash, skipped\n", |
| 179 | mtd->name); |
| 180 | return; |
| 181 | } |
| 182 | |
| 183 | if (!trx_mtd) |
| 184 | trxsplit_findtrx(mtd); |
| 185 | } |
| 186 | |
| 187 | static void __init trxsplit_remove_mtd(struct mtd_info *mtd) |
| 188 | { |
| 189 | /* nothing to do */ |
| 190 | } |
| 191 | |
| 192 | static struct mtd_notifier trxsplit_notifier __initdata = { |
| 193 | .add = trxsplit_add_mtd, |
| 194 | .remove = trxsplit_remove_mtd, |
| 195 | }; |
| 196 | |
| 197 | static void __init trxsplit_scan(void) |
| 198 | { |
| 199 | register_mtd_user(&trxsplit_notifier); |
| 200 | unregister_mtd_user(&trxsplit_notifier); |
| 201 | } |
| 202 | |
| 203 | static int __init trxsplit_init(void) |
| 204 | { |
| 205 | trxsplit_scan(); |
| 206 | |
| 207 | if (trx_mtd) { |
| 208 | printk(KERN_INFO PFX "creating TRX partitions in '%s' " |
| 209 | "(%d,%d)\n", trx_mtd->name, MTD_BLOCK_MAJOR, |
| 210 | trx_mtd->index); |
| 211 | trxsplit_create_partitions(trx_mtd); |
| 212 | } |
| 213 | |
| 214 | return 0; |
| 215 | } |
| 216 | |
| 217 | late_initcall(trxsplit_init); |
| 218 | |
