[LEDE-DEV] Sysupgrade leads to SQUASHFS error: unable to read id index table

[Petr Štetiar]

Hi,

I've found some issue with squashfs possibly related to mtdblock and mtdsplit
usage. Before digging deeper into it, I would like to ask first for any
pointers here.

I've recently rebased my Git tree to LEDE master and rebuilt my image (haven't
done this for month or so). I've noticed, that the resulting rootfs image has
grown from 5MB to 7MB(going to investigate this also soon), leading to the
following error SQUASHFS error:

  mmcblk0: mmc1:0001 004GE0 3.69 GiB
  mmcblk0boot0: mmc1:0001 004GE0 partition 1 2.00 MiB
  mmcblk0boot1: mmc1:0001 004GE0 partition 2 2.00 MiB
  mmcblk0rpmb: mmc1:0001 004GE0 partition 3 512 KiB
  3 cmdlinepart partitions found on MTD device eMMC
  Creating 3 MTD partitions on "eMMC":
  0x000000000000-0x000000080000 : "dtb"
  0x000000080000-0x000000480000 : "kernel"
  0x000000480000-0x000008480000 : "rootfs"
  mtd: device 2 (rootfs) set to be root filesystem
  1 squashfs-split partitions found on MTD device rootfs
  0x000000c80000-0x000008480000 : "rootfs_data"
  block2mtd: mtd0: [eMMC] erase_size = 512KiB [524288]
  squashfs: SQUASHFS error: unable to read id index table
  List of all partitions:
  b300         3866624 mmcblk0  driver: mmcblk
  b318             512 mmcblk0rpmb  (driver?)
  b310            2048 mmcblk0boot1  (driver?)
  b308            2048 mmcblk0boot0  (driver?)
  1f00             512 mtdblock0  (driver?)
  1f01            4096 mtdblock1  (driver?)
  1f02          131072 mtdblock2  (driver?)
  1f03          122880 mtdblock3  (driver?)
  No filesystem could mount root, tried:  ext3 ext4 ext2 squashfs
  Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,2)
  CPU0: stopping
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.36 #0
  Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
  Backtrace:
  [<800234c0>] (dump_backtrace) from [<800236b8>] (show_stack+0x18/0x1c)

My kernel commandline:

  block2mtd.block2mtd=/dev/mmcblk0,524288,eMMC,5 mtdparts=eMMC:512k(dtb),4M(kernel),128M(rootfs) rootwait console=ttymxc0,115200n8

Working MTD layout before sysupgrade (old 5M rootfs):

  Creating 3 MTD partitions on "eMMC":
  0x000000000000-0x000000080000 : "dtb"
  0x000000080000-0x000000480000 : "kernel"
  0x000000480000-0x000008480000 : "rootfs"
  mtd: device 2 (rootfs) set to be root filesystem
  1 squashfs-split partitions found on MTD device rootfs
  0x000000a00000-0x000008480000 : "rootfs_data"

My custom sysupgrade commands:

  tar -xOf "$1" sysupgrade-$board/dtb | mtd write - dtb
  tar -xOf "$1" sysupgrade-$board/kernel | mtd write - kernel
  tar -xOf "$1" sysupgrade-$board/rootfs | mtd write - rootfs

  if [ "$SAVE_CONFIG" -eq 1 ]; then
    mtd -e rootfs_data jffs2write "$CONF_TAR" rootfs_data
  else
    mtd erase rootfs_data
  fi


Thanks!

-- ynezz