package/block-mount/files/55_determine_extroot_sysupgrade

   1 #!/bin/sh
   2 # Copyright (C) 2010 Daniel Dickinson
   3 # This is free software, licensed under the GNU General Public License v2.
   4 # See /LICENSE for more information.
   5
   6
   7 check_set_md5sum() {
   8         local er_md5sum_file
   9         er_md5sum_file="${ER_OVERLAY_PREFIX}/.extroot.md5sum"
  10         local er_disabled
  11         if [ "${ER_OVERLAY_ROM}" = "/rom" ]; then
  12                 er_disabled=/tmp/whole_root-disabled
  13         else
  14                 er_disabled=/tmp${ER_OVERLAY_ROM}-disabled
  15         fi
  16
  17         local er_extroot_md5sum
  18         if [ -f $md5sum_file ]; then
  19                 er_extroot_md5sum="$(cat $er_md5sum_file)"
  20         fi
  21
  22         local er_overlay_file="${ER_OVERLAY_ROM}/etc/extroot.md5sum"
  23
  24         local er_extroot_overlay_md5sum
  25         if [ -f "$er_overlay_file" ]; then
  26                 er_extroot_overlay_md5sum="$(cat $er_overlay_file)"
  27         fi
  28
  29         if [ -z "$er_extroot_overlay_md5sum" ]; then
  30                 cat $er_md5sum_file >$er_overlay_file
  31         elif [ "$er_extroot_overlay_md5sum" != "$er_extroot_md5sum" ]; then
  32                 pi_extroot_mount_success="false"
  33                 mkdir -p $er_disabled
  34                 mount --move ${ER_OVERLAY_ROM} $er_disabled
  35         fi
  36 }
  37
  38 set_jffs_md5sum() {
  39         # We do this anytime block-extroot exists, even on the first boot with
  40         # no extroot defined.
  41
  42         local er_md5sum_file
  43         er_md5sum_file="${ER_OVERLAY_PREFIX}/.extroot.md5sum"
  44
  45         local er_extroot_md5sum
  46         if [ -f $er_md5sum_file ]; then
  47                 er_extroot_md5sum="$(cat $er_md5sum_file)"
  48         fi
  49         if [ -z "$er_extroot_md5sum" ]; then
  50                 dd if=/dev/urandom count=32 bs=1k 2>/dev/null | md5sum | cut -f1 -d\  >$er_md5sum_file
  51         fi
  52 }
  53
  54 determine_extroot_sysupgrade() {
  55         check_skip || set_jffs_md5sum
  56
  57         check_skip || [ "$pi_extroot_mount_success" != "true" ] || {
  58                 check_set_md5sum
  59         }
  60 }
  61
  62 boot_hook_add preinit_mount_root determine_extroot_sysupgrade
  63