diff --git a/main/postmarketos-initramfs/00-initramfs-base.files b/main/postmarketos-initramfs/00-initramfs-base.files
index c02c438a7..641ee304b 100644
--- a/main/postmarketos-initramfs/00-initramfs-base.files
+++ b/main/postmarketos-initramfs/00-initramfs-base.files
@@ -5,7 +5,7 @@
 /sbin/blkid
 /usr/bin/iskey
 /usr/bin/unudhcpd
-/usr/sbin/kpartx
+/usr/sbin/losetup
 /usr/share/deviceinfo/deviceinfo
 /usr/share/initramfs/init_functions.sh:/init_functions.sh
 /usr/share/initramfs/init.sh:/init
diff --git a/main/postmarketos-initramfs/00-initramfs-extra-base.files b/main/postmarketos-initramfs/00-initramfs-extra-base.files
index 586417e2e..59328d579 100644
--- a/main/postmarketos-initramfs/00-initramfs-extra-base.files
+++ b/main/postmarketos-initramfs/00-initramfs-extra-base.files
@@ -7,7 +7,6 @@
 /usr/lib/udev/rules.d/60-persistent-input.rules
 /usr/lib/udev/rules.d/60-persistent-storage.rules
 /usr/lib/udev/rules.d/64-btrfs.rules
-/usr/lib/udev/rules.d/66-kpartx.rules
 /usr/lib/udev/rules.d/70-mouse.rules
 /usr/lib/udev/rules.d/70-touchpad.rules
 /usr/lib/udev/rules.d/80-drivers.rules
diff --git a/main/postmarketos-initramfs/APKBUILD b/main/postmarketos-initramfs/APKBUILD
index 01b334332..91b17a6c0 100644
--- a/main/postmarketos-initramfs/APKBUILD
+++ b/main/postmarketos-initramfs/APKBUILD
@@ -1,7 +1,7 @@
 # Co-Maintainer: Clayton Craft <clayton@craftyguy.net>
 maintainer="Casey Connolly <kcxt@postmarketos.org>"
 pkgname=postmarketos-initramfs
-pkgver=3.8.12
+pkgver=3.9.0
 pkgrel=0
 pkgdesc="Base files for the postmarketOS initramfs / initramfs-extra"
 url="https://postmarketos.org"
@@ -28,8 +28,8 @@ depends="
 	iskey
 	kmod
 	libinput-libs
+	losetup
 	lz4
-	multipath-tools
 	parted
 	postmarketos-fde-unlocker
 	postmarketos-mkinitfs>=2.2
@@ -117,12 +117,12 @@ sha512sums="
 22cdd663c8d153781284511140b7c994cd60f0231a2819dafa67f5a11e2963ac6e392e8f7a9e3b75e7fe5d6d7b0b5e262e1ff1a695637354a124560a5ec3ed8d  00-default.modules
 ace852ba267b3408998970df6042603c8bec1d033066d1c30ed65f1be955fee8644b57882898f10228ec43b912f8f03718b34ddd741b431e5a5c2e76f060a494  00-default-extra.modules
 9c0e8f6f61d5da191e03a1aa9d5d0ceb5baf1eae6dbb9bfb0af59817783525119ac8394b135f303f7b6434a3eab0b49185fb90379e06823db847a4999c75ce33  00-initramfs-base.dirs
-9b5f5bc68ede0b06b85260d9ad301892e7b45ebad7e78300be17c8a55e3fdf392b3302587bd47011ce52f213e034a0cb49d0a2b96ab012fb5dce0514f4575aa7  00-initramfs-base.files
-3c021f6ede0c13469097a8aaeb15810baf2f3be52e10928f3475ac3568d855e3ab8e747b960d47ac6af6f7f223fca5e7da12098810502e0dae55aaf6bf4f293c  00-initramfs-extra-base.files
+26e391a2c45e4317549153630d7398f01cf374d9a95e2587f0f7153017c50b6640950af60eab3b3fcadef2e8826295445ac1f45567716d3bd5d12e9c87df599b  00-initramfs-base.files
+cc4db00caba184ad78062505415b3dadb8a32a94fe8484e4860bb6e63cd8700c8450066ce1242c496d9f063234bbab0fa40668f9c5112f3baeee30c5d405a1eb  00-initramfs-extra-base.files
 e90596540805662211bd2a2e427ce7cc38f6a30023267f902e23f2bae136b6cd8f4f4716b8fb611be9d671a964edd2ecce03fa32bc8024e29b8375b0097fde0c  init.sh
-8b0f15b84795588822a8b07b1e43ef0034da5f982ab92f0e7d3b9359fc61121f3f961006ba7d3f98f16d127d37ba833926654831b39e2df83d7384eebc786d3d  init_functions.sh
+3fd828e3ae67df2c3c1de9a0c2cdd087a4bc2a34029035b3fb74d410c9b46fd37b7e908eacdd65ee88b41cadb950a14f2b7c75c32bee413acbf5382dd5d1f7f2  init_functions.sh
 6b4881f9b43c90ebcc70d7b7a192d26a2e3ce01c43b8536fe900c2ffaf74ef035803b9aa083e7a9d5c49c75be8ba6ff22997a037ae4f399e6ee5e1978c4b3f9c  init_2nd.sh
-de14f6f678856ae316f28c003a6293a383aa6b7cbb19951b981430eb0e3b91d0634dedf62d29d105845b6e172daa18e6b6e45e03342d72ae806ca611a1236d18  init_functions_2nd.sh
+61acb470a163fb50ad46752781b5ccc5dba6db9170e4250b4dcdfc7572d0316a7a36bc5a383026887a7a59364ee30917790e429b3fce9de590543d1d8410589c  init_functions_2nd.sh
 675e7d5bee39b2df7d322117f8dcaccc274d61beaf4d50ead19bbf2109446d64b1c0aa0c5b4f9846eb6c1c403418f28f6364eff4537ba41120fbfcbc484b7da7  mdev.conf
 ba3275a9af788c7c782322a22a0f144d5e50e3498ea6886486a29331f23ae89cd32d500a3635cfa7cab369afba92edc18aeca64ccbf0cd589061cce23d15b46c  unudhcpd.conf
 "
diff --git a/main/postmarketos-initramfs/init_functions.sh b/main/postmarketos-initramfs/init_functions.sh
index f5f756ea6..7168dbd4c 100644
--- a/main/postmarketos-initramfs/init_functions.sh
+++ b/main/postmarketos-initramfs/init_functions.sh
@@ -7,6 +7,7 @@
 PMOS_BOOT="${PMOS_BOOT:-}"
 PMOS_ROOT="${PMOS_ROOT:-}"
 SUBPARTITION_DEV="${SUBPARTITION_DEV:-}"
+SUBPARTITION_LOOP="${SUBPARTITION_LOOP:-}"
 
 CONFIGFS="/config/usb_gadget"
 CONFIGFS_ACM_FUNCTION="acm.usb0"
@@ -18,6 +19,7 @@ deviceinfo_name="${deviceinfo_name:-}"
 deviceinfo_codename="${deviceinfo_codename:-}"
 deviceinfo_create_initfs_extra="${deviceinfo_create_initfs_extra:-}"
 deviceinfo_no_framebuffer="${deviceinfo_no_framebuffer:-}"
+deviceinfo_rootfs_image_sector_size="${deviceinfo_rootfs_image_sector_size:-}"
 
 # Does word start with prefix?
 startswith() {
@@ -356,6 +358,10 @@ mount_subpartitions() {
 		[ -e "$x" ] && android_parts="$android_parts $x"
 	done
 
+	local losetup_args="--show -Pfv --direct-io=on"
+	if [ -n "$deviceinfo_rootfs_image_sector_size" ]; then
+		losetup_args="$losetup_args --sector-size $deviceinfo_rootfs_image_sector_size"
+	fi
 	attempt_start=$(get_uptime_seconds)
 	wait_seconds=10
 	echo "Trying to mount subpartitions for $wait_seconds seconds..."
@@ -366,26 +372,30 @@ mount_subpartitions() {
 		for partition in $partitions; do
 		    # Skip whole disks - only check partitions and logical device-mapper devices for subpartitions
 			[ -e "/sys/class/block/$(basename "$partition")/partition" ] || [ -d "/sys/class/block/$(basename "$partition")/dm" ] || continue
-			case "$(kpartx -l "$partition" 2>/dev/null | wc -l)" in
-				2)
-					echo "Mount subpartitions of $partition"
-					SUBPARTITION_DEV="$partition"
-					kpartx -afs "$partition"
-					# Ensure that this was the *correct* subpartition
-					# Some devices have mmc partitions that appear to have
-					# subpartitions, but aren't our subpartition.
-					find_root_partition
-					if [ -n "$PMOS_ROOT" ]; then
-						break
-					fi
-					kpartx -d "$partition"
+			local part_count
+			part_count="$(parted -s "$partition" print 2>/dev/null | grep -c '^ [0-9]')"
+			# It's probably the right "disk" if it has 2 partitions on it
+			if [ "$part_count" -eq 2 ]; then
+				echo "Mount subpartitions of $partition"
+				SUBPARTITION_DEV="$partition"
+				# shellcheck disable=SC2086
+				SUBPARTITION_LOOP="$(losetup $losetup_args "$partition")"
+				if [ -z "$SUBPARTITION_LOOP" ]; then
+					echo "WARNING: failed to create loop device for $partition"
 					SUBPARTITION_DEV=""
 					continue
-					;;
-				*)
-					continue
-					;;
-			esac
+				fi
+				# Ensure that this was the *correct* subpartition
+				# Some devices have mmc partitions that appear to have
+				# subpartitions, but aren't our subpartition.
+				find_root_partition
+				if [ -n "$PMOS_ROOT" ]; then
+					break
+				fi
+				[ -n "$SUBPARTITION_LOOP" ] && losetup -vd "$SUBPARTITION_LOOP"
+				SUBPARTITION_DEV=""
+				SUBPARTITION_LOOP=""
+			fi
 		done
 		if [ "$(get_uptime_seconds)" -ge $(( attempt_start + wait_seconds )) ]; then
 			echo "ERROR: failed to mount subpartitions!"
diff --git a/main/postmarketos-initramfs/init_functions_2nd.sh b/main/postmarketos-initramfs/init_functions_2nd.sh
index 7e72beef3..543a92e52 100644
--- a/main/postmarketos-initramfs/init_functions_2nd.sh
+++ b/main/postmarketos-initramfs/init_functions_2nd.sh
@@ -31,42 +31,23 @@ resize_root_partition() {
 		return
 	fi
 
-	# Only resize the partition if it's inside the device-mapper, which means
-	# that the partition is stored as a subpartition inside another one.
-	# In this case we want to resize it to use all the unused space of the
-	# external partition.
-	if [ -z "${partition##"/dev/mapper/"*}" ] || [ -z "${partition##"/dev/dm-"*}" ]; then
-		# Get physical device
-		if [ -n "$SUBPARTITION_DEV" ]; then
-			partition_dev="$SUBPARTITION_DEV"
-		else
-			partition_dev=$(dmsetup deps -o blkdevname "$partition" | \
-				awk -F "[()]" '{print "/dev/"$2}')
-		fi
-		if has_unallocated_space "$partition_dev"; then
-			echo "Resize root partition ($partition)"
-			# unmount subpartition, resize and remount it
-			kpartx -d "$partition"
-			parted -f -s "$partition_dev" resizepart 2 100%
-			kpartx -afs "$partition_dev"
-		else
-			echo "Not resizing root partition ($partition): no free space left"
-		fi
+	local resize_dev="" check_dev="" partnum=2
 
+	# Always resize if using subpartitions, which means the partition
+	# is stored as a nested GPT inside another partition. In this case we want to
+	# resize the GPT so the inner root partition can make use of all the available
+	# space.
+	if [ -n "$SUBPARTITION_LOOP" ]; then
+		#
+		resize_dev="$SUBPARTITION_LOOP"
+		check_dev="$SUBPARTITION_LOOP"
 	# Resize the root partition (non-subpartitions). Usually we do not want
 	# this, except for QEMU devices and non-android devices (e.g.
 	# PinePhone). For them, it is fine to use the whole storage device and
 	# so we pass PMOS_FORCE_PARTITION_RESIZE as kernel parameter.
 	elif [ "$force_partition_resize" = "y" ]; then
-		partition_dev="$(echo "$partition" | sed -E 's/p?2$//')"
-		if has_unallocated_space "$partition_dev"; then
-			echo "Resize root partition ($partition)"
-			parted -f -s "$partition_dev" resizepart 2 100%
-			partprobe
-		else
-			echo "Not resizing root partition ($partition): no free space left"
-		fi
-
+		check_dev="$(echo "$partition" | sed -E 's/p?2$//')"
+		resize_dev="$check_dev"
 	# Resize the root partition (non-subpartitions) on Chrome OS devices.
 	# Match $deviceinfo_cgpt_kpart not being empty instead of cmdline
 	# because it does not make sense here as all these devices use the same
@@ -74,17 +55,21 @@ resize_root_partition() {
 	# second, because these devices have an additional kernel partition
 	# at the start.
 	elif [ -n "$deviceinfo_cgpt_kpart" ]; then
-		partition_dev="$(echo "$partition" | sed -E 's/p?3$//')"
-		if has_unallocated_space "$partition_dev"; then
-			echo "Resize root partition ($partition)"
-			parted -f -s "$partition_dev" resizepart 3 100%
-			partprobe
-		else
-			echo "Not resizing root partition ($partition): no free space left"
-		fi
-
+		check_dev="$(echo "$partition" | sed -E 's/p?3$//')"
+		resize_dev="$check_dev"
+		partnum=3
 	else
 		echo "Unable to resize root partition: failed to find qualifying partition"
+		return
+	fi
+
+	# Resize if needed
+	if has_unallocated_space "$check_dev"; then
+		echo "Resize root partition ($partition)"
+		parted -f -s "$resize_dev" resizepart "$partnum" 100%
+		partprobe
+	else
+		echo "Not resizing root partition ($partition): no free space left"
 	fi
 }