target/linux/ramips/rt305x/base-files/lib/preinit/04_handle_checksumming

   1 # Netgear WNCE2001 has does a checksum check on boot and goes into recovery
   2 # tftp mode when the check fails.  Initializing the JFFS2 partition triggers
   3 # this, so we make sure to zero checksum and size to be checksummed before
   4 # that happens, so this needs to run very early during boot.
   5
   6 do_checksumming_disable() {
   7         . /lib/functions.sh
   8
   9         local board=$(board_name)
  10
  11         case "$board" in
  12         netgear,wnce2001)
  13                 echo "Board is WNCE2001, updating checksum partition..."
  14                 local zeroes=/dev/zero
  15                 local tmpfile=/tmp/wnce2001_checksum
  16                 local partname=checksum
  17                 local mtd=$(find_mtd_part $partname)
  18                 dd if=$mtd of=$tmpfile bs=80 count=1 2>/dev/null
  19                 signature=$(dd if=$tmpfile bs=1 skip=24 count=20 2>/dev/null)
  20                 checksum=$(dd if=$tmpfile bs=1 count=4 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"')
  21                 if [ "$signature" != "RT3052-AP-WNCE2001-3" ]; then
  22                         echo "Signature of checksum partition is wrong, bailing."
  23                         return 0
  24                 fi
  25                 if [ "$checksum" != "00000000" ]; then
  26                         echo "Checksum is set, zeroing."
  27                         # zero out checksum
  28                         dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=0 count=4 2>/dev/null
  29                         # zero out bytecount to be checksummed
  30                         dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=60 count=4 2>/dev/null
  31                         mtd write $tmpfile $partname
  32                 else
  33                         echo "Checksum is already zero, nothing to do."
  34                 fi
  35         ;;
  36         esac
  37
  38         return 0
  39 }
  40
  41 boot_hook_add preinit_main do_checksumming_disable