target/linux/brcm47xx/patches-3.10/029-mtd-bcm47xxpart_detect_block_aligned_Squashfs_partition.patch

   1 mtd: bcm47xxpart: detect block aligned Squashfs partition
   2
   3 Most of the bcm47xx devices use TRX format for storing kernel and some
   4 partition like Squashfs or JFFS2. This is pretty flexible solution, CFE
   5 (the bootloader) just writes (and later boots) TRX at some hardcoded
   6 place and paritions can vary in the size.
   7
   8 However some devices don't use TRX format. Very recently we have
   9 discovered ZTE H218N that has kernel and rootfs partitions at some
  10 "random" places.
  11
  12 This patch allows Linux find a rootfs partition after installing custom
  13 image with a CFE bootloader.
  14
  15 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
  16
  17 --- a/drivers/mtd/bcm47xxpart.c
  18 +++ b/drivers/mtd/bcm47xxpart.c
  19 @@ -33,6 +33,7 @@
  20  #define ML_MAGIC1                      0x39685a42
  21  #define ML_MAGIC2                      0x26594131
  22  #define TRX_MAGIC                      0x30524448
  23 +#define SQSH_MAGIC                     0x71736873      /* shsq */
  24
  25  struct trx_header {
  26         uint32_t magic;
  27 @@ -170,6 +171,13 @@ static int bcm47xxpart_parse(struct mtd_
  28                         offset = rounddown(offset + trx->length, blocksize);
  29                         continue;
  30                 }
  31 +
  32 +               /* Squashfs on devices not using TRX */
  33 +               if (buf[0x000 / 4] == SQSH_MAGIC) {
  34 +                       bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
  35 +                                            offset, 0);
  36 +                       continue;
  37 +               }
  38         }
  39
  40         /* Look for NVRAM at the end of the last block. */