mvebu: sysupgrade: sdcard: keep user added partitons

Currently sysupgrade overwrites whole disk and destroys partitions added
by user. Sync the sysupgrade code with the one present in x86 target to
remedy this behaviour.

Signed-off-by: Tomasz Maciej Nowak <tomek_n@o2.pl>

2 files changed, 77 insertions, 6 deletions

diff --git a/target/linux/mvebu/base-files/lib/upgrade/platform.sh b/target/linux/mvebu/base-files/lib/upgrade/platform.sh
index e4ccf9d7f2..57b2f00a4c 100755
--- a/target/linux/mvebu/base-files/lib/upgrade/platform.sh
+++ b/target/linux/mvebu/base-files/lib/upgrade/platform.sh
@@ -8,7 +8,14 @@ RAMFS_COPY_DATA='/etc/fw_env.config /var/lock/fw_printenv.lock'
 REQUIRE_IMAGE_METADATA=1
 
 platform_check_image() {
-	return 0
+	case "$(board_name)" in
+	armada-385-turris-omnia|armada-388-clearfog-base|armada-388-clearfog-pro|globalscale,espressobin|marvell,armada8040-mcbin)
+		platform_check_image_sdcard "$ARGV"
+		;;
+	*)
+		return 0
+		;;
+	esac
 }
 
 platform_do_upgrade() {
diff --git a/target/linux/mvebu/base-files/lib/upgrade/sdcard.sh b/target/linux/mvebu/base-files/lib/upgrade/sdcard.sh
index 7aa91f463c..28fad31757 100644
--- a/target/linux/mvebu/base-files/lib/upgrade/sdcard.sh
+++ b/target/linux/mvebu/base-files/lib/upgrade/sdcard.sh
@@ -6,7 +6,7 @@ get_magic_at() {
 
 platform_check_image_sdcard() {
 	local file="$1"
-	local magic
+	local magic diskdev partdev diff
 
 	magic=$(get_magic_at "$file" 510)
 	[ "$magic" != "55aa" ] && {
@@ -14,18 +14,82 @@ platform_check_image_sdcard() {
 		return 1
 	}
 
-	return 0;
+	export_bootdevice && export_partdevice diskdev 0 || {
+		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
 }
 
 platform_do_upgrade_sdcard() {
 	local board=$(board_name)
-	local diskdev
+	local diskdev partdev diff
+
+	export_bootdevice && export_partdevice diskdev 0 || {
+		echo "Unable to determine upgrade device"
+	return 1
+	}
 
 	sync
-	if export_bootdevice && export_partdevice diskdev 0; then
-		get_image "$1" | dd of=/dev/$diskdev bs=2M conv=fsync
+
+	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/$diskdev" bs=4096 conv=fsync
+
+		# Separate removal and addtion is necessary; otherwise, partition 1
+		# will be missing if it overlaps with the old partition 2
+		partx -d - "/dev/$diskdev"
+		partx -a - "/dev/$diskdev"
+
+		return 0
 	fi
 
+	#write uboot image
+	get_image "$@" | dd of="$diskdev" bs=512 skip=1 seek=1 count=2048 conv=fsync
+	#iterate over each partition from the image and write it to the boot disk
+	while read part start size; do
+		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
+
 	case "$board" in
 	armada-385-turris-omnia)
 		fw_setenv openwrt_bootargs 'earlyprintk console=ttyS0,115200 root=/dev/mmcblk0p2 rootfstype=auto rootwait'