ar71xx: sysupgrade for My Net Wi-Fi Range Extender

This patch enables the convenient sysupgrade feature for
WD's Wi-Fi Range Extender.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Patchwork: http://patchwork.openwrt.org/patch/4341/
[juhosg:
  - rename 'mynet_rext_check_image' function to 'cybertan_check_image'
    and move that into platform.sh,
  - remove the the model specific 'platform_do_upgrade_mynet_rext' function,
  - drop the mynet-rext.sh script,
  - remove the image/Makefile change,
  - update commit message]
[christian:
  - check all 8 bytes of the firmware/device magic]
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 38966

target/linux/ar71xx/base-files/lib/ar71xx.sh

@@ -53,6 +53,15 @@ wndr3700_board_detect() {
 	AR71XX_MODEL="$machine"
 }
 
+cybertan_get_hw_magic() {
+	local part
+
+	part=$(find_mtd_part firmware)
+	[ -z "$part" ] && return 1
+
+	dd bs=8 count=1 skip=0 if=$part 2>/dev/null | hexdump -v -n 8 -e '1/1 "%02x"'
+}
+
 tplink_get_hwid() {
 	local part
 

target/linux/ar71xx/base-files/lib/upgrade/platform.sh

@@ -73,6 +73,22 @@ seama_get_type_magic() {
 	get_image "$@" | dd bs=1 count=4 skip=53 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"'
 }
 
+cybertan_get_image_magic() {
+	get_image "$@" | dd bs=8 count=1 skip=0  2>/dev/null | hexdump -v -n 8 -e '1/1 "%02x"'
+}
+
+cybertan_check_image() {
+	local magic="$(cybertan_get_image_magic "$1")"
+	local fw_magic="$(cybertan_get_hw_magic)"
+
+	[ "$fw_magic" != "$magic" ] && {
+		echo "Invalid image, ID mismatch, got:$magic, but need:$fw_magic"
+		return 1
+	}
+
+	return 0
+}
+
 platform_check_image() {
 	local board=$(ar71xx_board_name)
 	local magic="$(get_magic_word "$1")"
@@ -155,6 +171,11 @@ platform_check_image() {
 		dir825b_check_image "$1" && return 0
 		;;
 
+	mynet-rext)
+		cybertan_check_image "$1" && return 0
+		return 1
+		;;
+
 	mynet-n600)
 		[ "$magic_long" != "5ea3a417" ] && {
 			echo "Invalid image, bad magic: $magic_long"