scripts/linksys-image.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (C) 2018 Oceanic Systems (UK) Ltd
   4 #
   5 # This is free software, licensed under the GNU General Public License v2.
   6 # See /LICENSE for more information.
   7 #
   8 # Maintained by: Ryan Pannell <ryan [at] o s u k l .com> <github.com/Escalion>
   9 #
  10 # Write Linksys signature for factory image
  11 # This is appended to the factory image and is tested by the Linksys Upgrader - as observed in civic.
  12 # The footer is 256 bytes. The format is:
  13 #  .LINKSYS.        This is detected by the Linksys upgrader before continuing with upgrade. (9 bytes)
  14 #  <VERSION>        The version number of upgrade. Not checked so use arbitary value (8 bytes)
  15 #  <TYPE>           Model of target device, padded (0x20) to (15 bytes)
  16 #  <CRC>            CRC checksum of the image to flash (8 byte)
  17 #  <padding>        Padding (0x20) (7 bytes)
  18 #  <signature>      Signature of signer. Not checked so use Arbitary value (16 bytes)
  19 #  <padding>        Padding (0x00) (192 bytes)
  20 #  0x0A             (1 byte)
  21
  22 ## version history
  23 # * version 1: initial commit
  24
  25 set -e
  26
  27 ME="${0##*/}"
  28
  29 usage() {
  30         echo "Usage: $ME <type> <in filename>"
  31         [ "$IMG_OUT" ] && rm -f "$IMG_OUT"
  32         exit 1
  33 }
  34
  35 [ "$#" -lt 3 ] && usage
  36
  37 TYPE=$1
  38
  39 tmpdir="$( mktemp -d 2> /dev/null )"
  40 if [ -z "$tmpdir" ]; then
  41         # try OSX signature
  42         tmpdir="$( mktemp -t 'ubitmp' -d )"
  43 fi
  44
  45 if [ -z "$tmpdir" ]; then
  46         exit 1
  47 fi
  48
  49 trap "rm -rf $tmpdir" EXIT
  50
  51 IMG_TMP_OUT="${tmpdir}/out"
  52
  53 IMG_IN=$2
  54 IMG_OUT="${IMG_IN}.new"
  55
  56 [ ! -f "$IMG_IN" ] && echo "$ME: Not a valid image: $IMG_IN" && usage
  57
  58 dd if="${IMG_IN}" of="${IMG_TMP_OUT}"
  59 CRC=$(printf "%08X" $(dd if="${IMG_IN}" bs=$(stat -c%s "${IMG_IN}") count=1|cksum| cut -d ' ' -f1))
  60
  61 printf ".LINKSYS.01000409%-15s%-8s%-7s%-16s" "${TYPE}" "${CRC}" "" "K0000000F0246434" >> "${IMG_TMP_OUT}"
  62
  63 dd if=/dev/zero bs=1 count=192 conv=notrunc >> "${IMG_TMP_OUT}"
  64
  65 printf '\12' >> "${IMG_TMP_OUT}"
  66
  67 cp "${IMG_TMP_OUT}" "${IMG_OUT}"