Fix brcm2708 update

root/target/linux/brcm2708/base-files/lib/upgrade/platform.sh

@@ -0,0 +1,104 @@
+. /lib/functions.sh
+
+REQUIRE_IMAGE_METADATA=1
+
+# copied from x86's platform.sh
+
+platform_check_image() {
+	local diskdev partdev diff
+
+	[ "$#" -gt 1 ] && return 1
+
+	export_bootdevice && export_partdevice diskdev -2 || {
+		echo "Unable to determine upgrade device"
+		return 1
+	}
+
+	get_partitions "/dev/$diskdev" bootdisk
+
+	#extract the boot sector from the image
+	get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b 2>/dev/null
+
+	get_partitions /tmp/image.bs image
+
+	#compare tables
+	diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+
+	rm -f /tmp/image.bs /tmp/partmap.bootdisk /tmp/partmap.image
+
+	if [ -n "$diff" ]; then
+		echo "Partition layout has changed. Full image will be written."
+		ask_bool 0 "Abort" && exit 1
+		return 0
+	fi
+
+	return 0;
+}
+
+platform_do_upgrade() {
+	local diskdev partdev diff
+
+	export_bootdevice && export_partdevice diskdev -2 || {
+		echo "Unable to determine upgrade device"
+		return 1
+	}
+
+	sync
+
+	if [ "$SAVE_PARTITIONS" = "1" ]; then
+		get_partitions "/dev/$diskdev" bootdisk
+
+		#extract the boot sector from the image
+		get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
+
+		get_partitions /tmp/image.bs image
+
+		#compare tables
+		diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+	else
+		diff=1
+	fi
+
+	if [ -n "$diff" ]; then
+		get_image "$@" | dd of="/dev/$diskdev" bs=2M conv=fsync
+
+		# Separate removal and addtion is necessary; otherwise, partition 1
+		# will be missing if it overlaps with the old partition 2
+		partx -d - "/dev/$diskdev"
+		partx -a - "/dev/$diskdev"
+
+		return 0
+	fi
+
+	#iterate over each partition from the image and write it to the boot disk
+	while read part start size; do
+		# root is /dev/sd[a|b]2 and not /dev/sd[a|b] this causes some problem
+		# one of which is this offset, I'm not sure what's the best fix, so
+		# here's a WA.
+		let part=$((part - 2))
+		if export_partdevice partdev $part; then
+			echo "Writing image to /dev/$partdev..."
+			get_image "$@" | dd of="/dev/$partdev" ibs="512" obs=1M skip="$start" count="$size" conv=fsync
+		else
+			echo "Unable to find partition $part device, skipped."
+	fi
+	done < /tmp/partmap.image
+
+	#copy partition uuid
+	echo "Writing new UUID to /dev/$diskdev..."
+	get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
+}
+
+platform_copy_config() {
+	local partdev
+
+	# Same as above /dev/sd[a|b]2 is root, so /boot is -1
+	if export_partdevice partdev -1; then
+		mkdir -p /boot
+		[ -f /boot/kernel.img ] || mount -t vfat -o rw,noatime "/dev/$partdev" /boot
+		cp -af "$CONF_TAR" /boot/
+		tar -C / -xvf "$CONF_TAR" boot/config.txt
+		sync
+		unmount /boot
+	fi
+}