target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_uimage.c

   1 /*
   2  *  Copyright (C) 2013 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 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/slab.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/mtd/mtd.h>
  18 #include <linux/mtd/partitions.h>
  19 #include <linux/version.h>
  20 #include <linux/byteorder/generic.h>
  21 #include <linux/of.h>
  22
  23 #include "mtdsplit.h"
  24
  25 /*
  26  * uimage_header itself is only 64B, but it may be prepended with another data.
  27  * Currently the biggest size is for Edimax devices: 20B + 64B
  28  */
  29 #define MAX_HEADER_LEN          84
  30
  31 #define IH_MAGIC        0x27051956      /* Image Magic Number           */
  32 #define IH_NMLEN                32      /* Image Name Length            */
  33
  34 #define IH_OS_LINUX             5       /* Linux        */
  35
  36 #define IH_TYPE_KERNEL          2       /* OS Kernel Image              */
  37 #define IH_TYPE_FILESYSTEM      7       /* Filesystem Image             */
  38
  39 /*
  40  * Legacy format image header,
  41  * all data in network byte order (aka natural aka bigendian).
  42  */
  43 struct uimage_header {
  44         uint32_t        ih_magic;       /* Image Header Magic Number    */
  45         uint32_t        ih_hcrc;        /* Image Header CRC Checksum    */
  46         uint32_t        ih_time;        /* Image Creation Timestamp     */
  47         uint32_t        ih_size;        /* Image Data Size              */
  48         uint32_t        ih_load;        /* Data  Load  Address          */
  49         uint32_t        ih_ep;          /* Entry Point Address          */
  50         uint32_t        ih_dcrc;        /* Image Data CRC Checksum      */
  51         uint8_t         ih_os;          /* Operating System             */
  52         uint8_t         ih_arch;        /* CPU architecture             */
  53         uint8_t         ih_type;        /* Image Type                   */
  54         uint8_t         ih_comp;        /* Compression Type             */
  55         uint8_t         ih_name[IH_NMLEN];      /* Image Name           */
  56 };
  57
  58 static int
  59 read_uimage_header(struct mtd_info *mtd, size_t offset, u_char *buf,
  60                    size_t header_len)
  61 {
  62         size_t retlen;
  63         int ret;
  64
  65         ret = mtd_read(mtd, offset, header_len, &retlen, buf);
  66         if (ret) {
  67                 pr_debug("read error in \"%s\"\n", mtd->name);
  68                 return ret;
  69         }
  70
  71         if (retlen != header_len) {
  72                 pr_debug("short read in \"%s\"\n", mtd->name);
  73                 return -EIO;
  74         }
  75
  76         return 0;
  77 }
  78
  79 /**
  80  * __mtdsplit_parse_uimage - scan partition and create kernel + rootfs parts
  81  *
  82  * @find_header: function to call for a block of data that will return offset
  83  *      of a valid uImage header if found
  84  */
  85 static int __mtdsplit_parse_uimage(struct mtd_info *master,
  86                                    const struct mtd_partition **pparts,
  87                                    struct mtd_part_parser_data *data,
  88                                    ssize_t (*find_header)(u_char *buf, size_t len))
  89 {
  90         struct mtd_partition *parts;
  91         u_char *buf;
  92         int nr_parts;
  93         size_t offset;
  94         size_t uimage_offset;
  95         size_t uimage_size = 0;
  96         size_t rootfs_offset;
  97         size_t rootfs_size = 0;
  98         int uimage_part, rf_part;
  99         int ret;
 100         enum mtdsplit_part_type type;
 101
 102         nr_parts = 2;
 103         parts = kzalloc(nr_parts * sizeof(*parts), GFP_KERNEL);
 104         if (!parts)
 105                 return -ENOMEM;
 106
 107         buf = vmalloc(MAX_HEADER_LEN);
 108         if (!buf) {
 109                 ret = -ENOMEM;
 110                 goto err_free_parts;
 111         }
 112
 113         /* find uImage on erase block boundaries */
 114         for (offset = 0; offset < master->size; offset += master->erasesize) {
 115                 struct uimage_header *header;
 116
 117                 uimage_size = 0;
 118
 119                 ret = read_uimage_header(master, offset, buf, MAX_HEADER_LEN);
 120                 if (ret)
 121                         continue;
 122
 123                 ret = find_header(buf, MAX_HEADER_LEN);
 124                 if (ret < 0) {
 125                         pr_debug("no valid uImage found in \"%s\" at offset %llx\n",
 126                                  master->name, (unsigned long long) offset);
 127                         continue;
 128                 }
 129                 header = (struct uimage_header *)(buf + ret);
 130
 131                 uimage_size = sizeof(*header) + be32_to_cpu(header->ih_size) + ret;
 132                 if ((offset + uimage_size) > master->size) {
 133                         pr_debug("uImage exceeds MTD device \"%s\"\n",
 134                                  master->name);
 135                         continue;
 136                 }
 137                 break;
 138         }
 139
 140         if (uimage_size == 0) {
 141                 pr_debug("no uImage found in \"%s\"\n", master->name);
 142                 ret = -ENODEV;
 143                 goto err_free_buf;
 144         }
 145
 146         uimage_offset = offset;
 147
 148         if (uimage_offset == 0) {
 149                 uimage_part = 0;
 150                 rf_part = 1;
 151
 152                 /* find the roots after the uImage */
 153                 ret = mtd_find_rootfs_from(master, uimage_offset + uimage_size,
 154                                            master->size, &rootfs_offset, &type);
 155                 if (ret) {
 156                         pr_debug("no rootfs after uImage in \"%s\"\n",
 157                                  master->name);
 158                         goto err_free_buf;
 159                 }
 160
 161                 rootfs_size = master->size - rootfs_offset;
 162                 uimage_size = rootfs_offset - uimage_offset;
 163         } else {
 164                 rf_part = 0;
 165                 uimage_part = 1;
 166
 167                 /* check rootfs presence at offset 0 */
 168                 ret = mtd_check_rootfs_magic(master, 0, &type);
 169                 if (ret) {
 170                         pr_debug("no rootfs before uImage in \"%s\"\n",
 171                                  master->name);
 172                         goto err_free_buf;
 173                 }
 174
 175                 rootfs_offset = 0;
 176                 rootfs_size = uimage_offset;
 177         }
 178
 179         if (rootfs_size == 0) {
 180                 pr_debug("no rootfs found in \"%s\"\n", master->name);
 181                 ret = -ENODEV;
 182                 goto err_free_buf;
 183         }
 184
 185         parts[uimage_part].name = KERNEL_PART_NAME;
 186         parts[uimage_part].offset = uimage_offset;
 187         parts[uimage_part].size = uimage_size;
 188
 189         if (type == MTDSPLIT_PART_TYPE_UBI)
 190                 parts[rf_part].name = UBI_PART_NAME;
 191         else
 192                 parts[rf_part].name = ROOTFS_PART_NAME;
 193         parts[rf_part].offset = rootfs_offset;
 194         parts[rf_part].size = rootfs_size;
 195
 196         vfree(buf);
 197
 198         *pparts = parts;
 199         return nr_parts;
 200
 201 err_free_buf:
 202         vfree(buf);
 203
 204 err_free_parts:
 205         kfree(parts);
 206         return ret;
 207 }
 208
 209 static ssize_t uimage_verify_default(u_char *buf, size_t len)
 210 {
 211         struct uimage_header *header = (struct uimage_header *)buf;
 212
 213         /* default sanity checks */
 214         if (be32_to_cpu(header->ih_magic) != IH_MAGIC) {
 215                 pr_debug("invalid uImage magic: %08x\n",
 216                          be32_to_cpu(header->ih_magic));
 217                 return -EINVAL;
 218         }
 219
 220         if (header->ih_os != IH_OS_LINUX) {
 221                 pr_debug("invalid uImage OS: %08x\n",
 222                          be32_to_cpu(header->ih_os));
 223                 return -EINVAL;
 224         }
 225
 226         if (header->ih_type != IH_TYPE_KERNEL) {
 227                 pr_debug("invalid uImage type: %08x\n",
 228                          be32_to_cpu(header->ih_type));
 229                 return -EINVAL;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int
 236 mtdsplit_uimage_parse_generic(struct mtd_info *master,
 237                               const struct mtd_partition **pparts,
 238                               struct mtd_part_parser_data *data)
 239 {
 240         return __mtdsplit_parse_uimage(master, pparts, data,
 241                                       uimage_verify_default);
 242 }
 243
 244 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 245 static const struct of_device_id mtdsplit_uimage_of_match_table[] = {
 246         { .compatible = "denx,uimage" },
 247         {},
 248 };
 249 #endif
 250
 251 static struct mtd_part_parser uimage_generic_parser = {
 252         .owner = THIS_MODULE,
 253         .name = "uimage-fw",
 254 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 255         .of_match_table = mtdsplit_uimage_of_match_table,
 256 #endif
 257         .parse_fn = mtdsplit_uimage_parse_generic,
 258         .type = MTD_PARSER_TYPE_FIRMWARE,
 259 };
 260
 261 #define FW_MAGIC_WNR2000V1      0x32303031
 262 #define FW_MAGIC_WNR2000V3      0x32303033
 263 #define FW_MAGIC_WNR2000V4      0x32303034
 264 #define FW_MAGIC_WNR2200        0x32323030
 265 #define FW_MAGIC_WNR612V2       0x32303631
 266 #define FW_MAGIC_WNR1000V2      0x31303031
 267 #define FW_MAGIC_WNR1000V2_VC   0x31303030
 268 #define FW_MAGIC_WNDR3700       0x33373030
 269 #define FW_MAGIC_WNDR3700V2     0x33373031
 270 #define FW_MAGIC_WPN824N        0x31313030
 271
 272 static ssize_t uimage_verify_wndr3700(u_char *buf, size_t len)
 273 {
 274         struct uimage_header *header = (struct uimage_header *)buf;
 275         uint8_t expected_type = IH_TYPE_FILESYSTEM;
 276
 277         switch (be32_to_cpu(header->ih_magic)) {
 278         case FW_MAGIC_WNR612V2:
 279         case FW_MAGIC_WNR1000V2:
 280         case FW_MAGIC_WNR1000V2_VC:
 281         case FW_MAGIC_WNR2000V1:
 282         case FW_MAGIC_WNR2000V3:
 283         case FW_MAGIC_WNR2200:
 284         case FW_MAGIC_WNDR3700:
 285         case FW_MAGIC_WNDR3700V2:
 286         case FW_MAGIC_WPN824N:
 287                 break;
 288         case FW_MAGIC_WNR2000V4:
 289                 expected_type = IH_TYPE_KERNEL;
 290                 break;
 291         default:
 292                 return -EINVAL;
 293         }
 294
 295         if (header->ih_os != IH_OS_LINUX ||
 296             header->ih_type != expected_type)
 297                 return -EINVAL;
 298
 299         return 0;
 300 }
 301
 302 static int
 303 mtdsplit_uimage_parse_netgear(struct mtd_info *master,
 304                               const struct mtd_partition **pparts,
 305                               struct mtd_part_parser_data *data)
 306 {
 307         return __mtdsplit_parse_uimage(master, pparts, data,
 308                                       uimage_verify_wndr3700);
 309 }
 310
 311 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 312 static const struct of_device_id mtdsplit_uimage_netgear_of_match_table[] = {
 313         { .compatible = "netgear,uimage" },
 314         {},
 315 };
 316 #endif
 317
 318 static struct mtd_part_parser uimage_netgear_parser = {
 319         .owner = THIS_MODULE,
 320         .name = "netgear-fw",
 321 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 322         .of_match_table = mtdsplit_uimage_netgear_of_match_table,
 323 #endif
 324         .parse_fn = mtdsplit_uimage_parse_netgear,
 325         .type = MTD_PARSER_TYPE_FIRMWARE,
 326 };
 327
 328 /**************************************************
 329  * Edimax
 330  **************************************************/
 331
 332 #define FW_EDIMAX_OFFSET        20
 333 #define FW_MAGIC_EDIMAX         0x43535953
 334
 335 static ssize_t uimage_find_edimax(u_char *buf, size_t len)
 336 {
 337         u32 *magic;
 338
 339         if (len < FW_EDIMAX_OFFSET + sizeof(struct uimage_header)) {
 340                 pr_err("Buffer too small for checking Edimax header\n");
 341                 return -ENOSPC;
 342         }
 343
 344         magic = (u32 *)buf;
 345         if (be32_to_cpu(*magic) != FW_MAGIC_EDIMAX)
 346                 return -EINVAL;
 347
 348         if (!uimage_verify_default(buf + FW_EDIMAX_OFFSET, len))
 349                 return FW_EDIMAX_OFFSET;
 350
 351         return -EINVAL;
 352 }
 353
 354 static int
 355 mtdsplit_uimage_parse_edimax(struct mtd_info *master,
 356                               const struct mtd_partition **pparts,
 357                               struct mtd_part_parser_data *data)
 358 {
 359         return __mtdsplit_parse_uimage(master, pparts, data,
 360                                        uimage_find_edimax);
 361 }
 362
 363 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 364 static const struct of_device_id mtdsplit_uimage_edimax_of_match_table[] = {
 365         { .compatible = "edimax,uimage" },
 366         {},
 367 };
 368 #endif
 369
 370 static struct mtd_part_parser uimage_edimax_parser = {
 371         .owner = THIS_MODULE,
 372         .name = "edimax-fw",
 373 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 374         .of_match_table = mtdsplit_uimage_edimax_of_match_table,
 375 #endif
 376         .parse_fn = mtdsplit_uimage_parse_edimax,
 377         .type = MTD_PARSER_TYPE_FIRMWARE,
 378 };
 379
 380 /**************************************************
 381  * Init
 382  **************************************************/
 383
 384 static int __init mtdsplit_uimage_init(void)
 385 {
 386         register_mtd_parser(&uimage_generic_parser);
 387         register_mtd_parser(&uimage_netgear_parser);
 388         register_mtd_parser(&uimage_edimax_parser);
 389
 390         return 0;
 391 }
 392
 393 module_init(mtdsplit_uimage_init);