build: add a script for generating Linksys factory images

[openwrt/staging/dedeckeh.git] / scripts / linksys-image.sh

diff --git a/scripts/linksys-image.sh b/scripts/linksys-image.sh
new file mode 100755 (executable)
index 0000000..36a676d
--- /dev/null
+++ b/scripts/linksys-image.sh
@@ -0,0 +1,67 @@
+#!/bin/sh
+#
+# Copyright (C) 2018 Oceanic Systems (UK) Ltd
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+# Maintained by: Ryan Pannell <ryan [at] o s u k l .com> <github.com/Escalion>
+#
+# Write Linksys signature for factory image
+# This is appended to the factory image and is tested by the Linksys Upgrader - as observed in civic.
+# The footer is 256 bytes. The format is:
+#  .LINKSYS.        This is detected by the Linksys upgrader before continuing with upgrade. (9 bytes)
+#  <VERSION>        The version number of upgrade. Not checked so use arbitary value (8 bytes)
+#  <TYPE>           Model of target device, padded (0x20) to (15 bytes)
+#  <CRC>           CRC checksum of the image to flash (8 byte)
+#  <padding>       Padding (0x20) (7 bytes)
+#  <signature>     Signature of signer. Not checked so use Arbitary value (16 bytes)
+#  <padding>        Padding (0x00) (192 bytes)
+#  0x0A                    (1 byte)
+
+## version history
+# * version 1: initial commit
+
+set -e
+
+ME="${0##*/}"
+
+usage() {
+       echo "Usage: $ME <type> <in filename>"
+       [ "$IMG_OUT" ] && rm -f "$IMG_OUT"
+       exit 1
+}
+
+[ "$#" -lt 3 ] && usage
+
+TYPE=$1
+
+tmpdir="$( mktemp -d 2> /dev/null )"
+if [ -z "$tmpdir" ]; then
+       # try OSX signature
+       tmpdir="$( mktemp -t 'ubitmp' -d )"
+fi
+
+if [ -z "$tmpdir" ]; then
+       exit 1
+fi
+
+trap "rm -rf $tmpdir" EXIT
+
+IMG_TMP_OUT="${tmpdir}/out"
+
+IMG_IN=$2
+IMG_OUT="${IMG_IN}.new"
+
+[ ! -f "$IMG_IN" ] && echo "$ME: Not a valid image: $IMG_IN" && usage
+
+dd if="${IMG_IN}" of="${IMG_TMP_OUT}"
+CRC=$(printf "%08X" $(dd if="${IMG_IN}" bs=$(stat -c%s "${IMG_IN}") count=1|cksum| cut -d ' ' -f1))
+
+printf ".LINKSYS.01000409%-15s%-8s%-7s%-16s" "${TYPE}" "${CRC}" "" "K0000000F0246434" >> "${IMG_TMP_OUT}"
+
+dd if=/dev/zero bs=1 count=192 conv=notrunc >> "${IMG_TMP_OUT}"
+
+printf '\12' >> "${IMG_TMP_OUT}"
+
+cp "${IMG_TMP_OUT}" "${IMG_OUT}"