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

   1 #!/bin/sh
   2
   3 # Netgear WNCE2001 has does a checksum check on boot and goes into recovery
   4 # tftp mode when the check fails.  Initializing the JFFS2 partition triggers
   5 # this, so we make sure to zero checksum and size to be checksummed before
   6 # that happens, so this needs to run very early during boot.
   7
   8 do_checksumming_disable() {
   9         . /lib/ramips.sh
  10
  11         local board=$(ramips_board_name)
  12
  13         case "$board" in
  14         wnce2001)
  15                 echo "Board is WNCE2001, updating checksum partition..."
  16                 local zeroes=/dev/zero
  17                 local tmpfile=/tmp/wnce2001_checksum
  18                 local partname=checksum
  19                 local mtd=$(find_mtd_part $partname)
  20                 dd if=$mtd of=$tmpfile bs=80 count=1 2>/dev/null
  21                 signature=$(dd if=$tmpfile bs=1 skip=24 count=20 2>/dev/null)
  22                 checksum=$(dd if=$tmpfile bs=1 count=4 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"')
  23                 if [ "$signature" != "RT3052-AP-WNCE2001-3" ]; then
  24                         echo "Signature of checksum partition is wrong, bailing."
  25                         return 0
  26                 fi
  27                 if [ "$checksum" != "00000000" ]; then
  28                         echo "Checksum is set, zeroing."
  29                         # zero out checksum
  30                         dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=0 count=4 2>/dev/null
  31                         # zero out bytecount to be checksummed
  32                         dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=60 count=4 2>/dev/null
  33                         mtd write $tmpfile $partname
  34                 else
  35                         echo "Checksum is already zero, nothing to do."
  36                 fi
  37         ;;
  38         rt-n56u)
  39                 echo "Board is ASUS RT-N56U, replacing uImage header..."
  40                 local firmware_mtd=$(find_mtd_part firmware)
  41                 local rootfs_mtd=$(find_mtd_part rootfs)
  42                 local rootfs_data_mtd=$(find_mtd_part rootfs_data)
  43                 local rootfs_len=$(grep \"rootfs\" /proc/mtd | awk -F' ' '{print "0x"$2}')
  44                 local rootfs_data_len=$(grep \"rootfs_data\" /proc/mtd | awk -F' ' '{print "0x"$2}')
  45                 local offset=$(echo "$rootfs_len $rootfs_data_len 0x40" | awk -F' ' '{printf "%i",$1-$2-$3}')
  46                 local signature=$(dd if=$rootfs_mtd skip=$offset bs=1 count=4 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"')
  47                 if [ "$signature" = "27051956" ]; then
  48                         dd conv=notrunc if=$rootfs_mtd skip=$offset of=$firmware_mtd bs=1 count=64 2>/dev/null
  49                 fi
  50         ;;
  51         esac
  52
  53         return 0
  54 }
  55
  56 boot_hook_add preinit_main do_checksumming_disable