diff --git a/build-initrd.sh b/build-initrd.sh
index 473de43..e49fda9 100755
--- a/build-initrd.sh
+++ b/build-initrd.sh
@@ -5,6 +5,8 @@ set -e
 export FLASH_KERNEL_SKIP=1
 export DEBIAN_FRONTEND=noninteractive
 DEFAULTMIRROR="https://deb.debian.org/debian"
+DEFAULTUBPORTSMIRROR="http://repo.ubports.com/"
+UBPORTSKEYRING="https://repo.ubports.com/keyring.gpg"
 APT_COMMAND="apt -y"
 
 usage() {
@@ -38,12 +40,14 @@ done
 # Defaults for all arguments, so they can be set by the environment
 [ -z $ARCH ] && ARCH="armhf"
 [ -z $MIRROR ] && MIRROR=$DEFAULTMIRROR
-[ -z $RELEASE ] && RELEASE="stretch"
+[ -z $UBPORTSMIRROR ] && UBPORTSMIRROR=$DEFAULTUBPORTSMIRROR
+[ -z $RELEASE ] && RELEASE="buster"
+[ -z $UBPORTSRELEASE ] && UBPORTSRELEASE="xenial"
 [ -z $ROOT ] && ROOT=./build/$ARCH
 [ -z $OUT ] && OUT=./out
 
 # list all packages needed for halium's initrd here
-[ -z $INCHROOTPKGS ] && INCHROOTPKGS="initramfs-tools dctrl-tools e2fsprogs libc6-dev zlib1g-dev libssl-dev busybox-static"
+[ -z $INCHROOTPKGS ] && INCHROOTPKGS="initramfs-tools dctrl-tools dmsetup e2fsprogs libc6-dev zlib1g-dev libssl-dev busybox-static parse-android-dynparts"
 
 BOOTSTRAP_BIN="qemu-debootstrap --arch $ARCH --variant=minbase"
 
@@ -76,6 +80,11 @@ if [ ! -e $ROOT/.min-done ]; then
 
 	#sed -i 's/main$/main universe/' $ROOT/etc/apt/sources.list
 	sed -i 's,'"$DEFAULTMIRROR"','"$MIRROR"',' $ROOT/etc/apt/sources.list
+	mkdir -p $ROOT/etc/apt/sources.list.d
+	echo "deb $UBPORTSMIRROR $UBPORTSRELEASE main" > $ROOT/etc/apt/sources.list.d/ubports.list
+
+	mkdir -p $ROOT/etc/apt/trusted.gpg.d
+	wget "$UBPORTSKEYRING" -O $ROOT/etc/apt/trusted.gpg.d/ubports.gpg
 
 	# make sure we do not start daemons at install time
 	mv $ROOT/sbin/start-stop-daemon $ROOT/sbin/start-stop-daemon.REAL
diff --git a/hooks/halium b/hooks/halium
index 29f31e1..ff72866 100755
--- a/hooks/halium
+++ b/hooks/halium
@@ -23,7 +23,9 @@ copy_exec /sbin/e2fsck /sbin
 copy_exec /sbin/resize2fs /sbin
 copy_exec /bin/chown /bin
 copy_exec /bin/mount /bin
+copy_exec /sbin/dmsetup /sbin
 copy_exec /sbin/dumpe2fs /sbin
 copy_exec /lib/$DEB_HOST_MULTIARCH/libz.so.1
 copy_exec /usr/lib/$DEB_HOST_MULTIARCH/libcrypto.so
 copy_exec /usr/lib/$DEB_HOST_MULTIARCH/libdl.so
+copy_exec /usr/sbin/parse-android-dynparts /sbin
diff --git a/scripts/halium b/scripts/halium
index 7dea11e..8bcce85 100644
--- a/scripts/halium
+++ b/scripts/halium
@@ -486,15 +486,36 @@ mountroot() {
 	[ `blkid $path -o value -s TYPE` = "ext4" ] && OPTIONS="data=journal,"
 	mount -o discard,$OPTIONS $path /tmpmnt
 
+	# setup super partition if exists
+	if [ -n "/dev/disk/by-partlabel/super" ]; then
+		tell_kmsg "trying to parse and dmsetup subpartitions from super partition"
+		/sbin/parse-android-dynparts /dev/disk/by-partlabel/super | sh
+	fi
+
 	# Set $_syspart if it is specified as systempart= on the command line
 	if grep -q systempart= /proc/cmdline; then
 		for x in $(cat /proc/cmdline); do
 			case ${x} in
 			systempart=*)
 				_syspart=${x#*=}
+				if [ -z ${_syspart##*:*} ]; then
+					_syspart_options=${_syspart##*:}
+					_syspart=${_syspart%%:*}
+				fi
 				;;
 			esac
 		done
+
+		if [ -z "$_syspart_options" ]; then
+			_syspart_options=rw
+		fi
+	fi
+
+	# We need to add the slot suffix to $_syspart for A/B devices
+	if [ -n "$_syspart" ] && [ ! -e "$_syspart" ] && [ ! -z "$ab_slot_suffix" ]; then
+		tell_kmsg "A/B slot system detected! Slot suffix is $ab_slot_suffix"
+		_syspart="${_syspart}${ab_slot_suffix}"
+		tell_kmsg "system partition is at $_syspart"
 	fi
 
 	identify_file_layout
@@ -514,7 +535,7 @@ mountroot() {
 
 	tell_kmsg "mounting system rootfs at /halium-system"
 	if [ -n "$_syspart" ]; then
-		mount -o rw $_syspart /halium-system
+		mount -o "$_syspart_options" $_syspart /halium-system
 	elif [ -f "$imagefile" ]; then
 		# Rootfs is an image file
 		mount -o loop,rw $imagefile /halium-system
@@ -530,6 +551,12 @@ mountroot() {
 	identify_android_image
 	[ $ANDROID_IMAGE_MODE = "unknown" ] && tell_kmsg "WARNING: Android system image not found."
 
+	if { [ -n "$_syspart_options" ] && [ -z "${_syspart_options##*ro*}" ]; } || [ -e /tmpmnt/.writable_image_overlay ] || [ -e /halium-system/.writable_image_overlay ]; then
+		# If systempart had to be mounted ro, mount rw overlayfs on top
+		mkdir -p /tmpmnt/rootfs-overlay /tmpmnt/rootfs-overlay-workdir
+		mount -t overlay rootfs -o lowerdir=/halium-system,upperdir=/tmpmnt/rootfs-overlay,workdir=/tmpmnt/rootfs-overlay-workdir /halium-system
+	fi
+
 	# If either (android) /data/.writable_image or (on rootfs)
 	# /.writable_image exist, mount the rootfs as rw
 	if [ -e /tmpmnt/.writable_image ] || [ -e /halium-system/.writable_image ]; then