diff -Nru flash-kernel-3.104ubuntu8/db/all.db flash-kernel-3.104ubuntu9/db/all.db
--- flash-kernel-3.104ubuntu8/db/all.db	2022-04-03 17:32:44.000000000 +0000
+++ flash-kernel-3.104ubuntu9/db/all.db	2022-04-18 11:13:13.000000000 +0000
@@ -1671,10 +1671,14 @@
 Required-Packages: u-boot-tools
 Boot-Script-Path: /boot/boot.scr
 
+# Please ignore the DTB-Id in the following entries; the "pi" method copies
+# *all* dtbs (including all dtb overlays) found to ensure that the storage can
+# be moved between supported models.
+
 Machine: Raspberry Pi 2 Model B
 Machine: Raspberry Pi 2 Model B Rev 1.1
 Machine: Raspberry Pi 2 Model B Rev 1.2
-Kernel-Flavors: raspi
+Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2709-rpi-2-b.dtb
 U-Boot-Script-Name: bootscr.rpi
@@ -1683,7 +1687,7 @@
 Machine: Raspberry Pi 3 Model A+
 Machine: Raspberry Pi 3 Model A Plus
 Machine: Raspberry Pi 3 Model A Plus Rev 1.0
-Kernel-Flavors: raspi
+Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2710-rpi-3-b-plus.dtb
 U-Boot-Script-Name: bootscr.rpi
@@ -1693,7 +1697,7 @@
 # Raspberry Pi 3 (BCM2710)
 Machine: Raspberry Pi 3 Model B
 Machine: Raspberry Pi 3 Model B Rev 1.2
-Kernel-Flavors: raspi
+Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2710-rpi-3-b.dtb
 U-Boot-Script-Name: bootscr.rpi
@@ -1702,7 +1706,7 @@
 Machine: Raspberry Pi 3 Model B+
 Machine: Raspberry Pi 3 Model B Plus
 Machine: Raspberry Pi 3 Model B Plus Rev 1.3
-Kernel-Flavors: raspi
+Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2710-rpi-3-b-plus.dtb
 U-Boot-Script-Name: bootscr.rpi
@@ -1712,24 +1716,37 @@
 Machine: Raspberry Pi 4 Model B Rev 1.1
 Machine: Raspberry Pi 4 Model B Rev 1.2
 Machine: Raspberry Pi 4 Model B Rev 1.4
-Machine: Raspberry Pi Compute Module 4 Rev 1.0
-Machine: Raspberry Pi 400 Rev 1.0
-Machine: Raspberry Pi 400 Rev 1.1
+Machine: Raspberry Pi 4 Model B Rev 1.5
 Machine: Raspberry Pi *
-Kernel-Flavors: raspi
+Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2711-rpi-4-b.dtb
 U-Boot-Script-Name: bootscr.rpi
 Required-Packages: u-boot-tools
 
+Machine: Raspberry Pi 400 Rev 1.0
+Machine: Raspberry Pi 400 Rev 1.1
+Kernel-Flavors: raspi raspi-nolpae
+Method: pi
+DTB-Id: bcm2711-rpi-400.dtb
+U-Boot-Script-Name: bootscr.rpi
+Required-Packages: u-boot-tools
+
 Machine: Raspberry Pi Compute Module 3 Rev 1.0
 Machine: Raspberry Pi Compute Module 3 Plus Rev 1.0
-Kernel-Flavors: raspi
+Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2710-rpi-cm3.dtb
 U-Boot-Script-Name: bootscr.rpi
 Required-Packages: u-boot-tools
 
+Machine: Raspberry Pi Compute Module 4 Rev 1.0
+Kernel-Flavors: raspi raspi-nolpae
+Method: pi
+DTB-Id: bcm2711-rpi-cm4.dtb
+U-Boot-Script-Name: bootscr.rpi
+Required-Packages: u-boot-tools
+
 Machine: Raspberry Pi Zero
 Kernel-Flavors: rpi
 DTB-Id: bcm2835-rpi-zero.dtb
diff -Nru flash-kernel-3.104ubuntu8/debian/changelog flash-kernel-3.104ubuntu9/debian/changelog
--- flash-kernel-3.104ubuntu8/debian/changelog	2022-04-03 17:33:03.000000000 +0000
+++ flash-kernel-3.104ubuntu9/debian/changelog	2022-04-18 11:13:13.000000000 +0000
@@ -1,3 +1,16 @@
+flash-kernel (3.104ubuntu9) jammy; urgency=medium
+
+  * Cache lookup of Bootloader-Has-Broken-Ext4-Extent-Support for significant
+    performance improvement on Raspberry Pi (LP: #1965129)
+  * Added note in db/all.db above Pi entries about "incorrect" DTB-Id
+    (LP: #1928314)
+  * Add raspi-nolpae kernel flavor to all supported boards (LP: #1962312)
+  * Added entries for the Pi 4B rev 1.5, and moved CM4 and 400 models to their
+    own entries for the sake of clarity
+  * Include overlays/README in the files copied by Method: pi
+
+ -- Dave Jones <dave.jones@canonical.com>  Mon, 18 Apr 2022 12:13:13 +0100
+
 flash-kernel (3.104ubuntu8) jammy; urgency=medium
 
   * mkimage_fit: subst KERNEL_VERSION in ITS file with actual kernel
diff -Nru flash-kernel-3.104ubuntu8/functions flash-kernel-3.104ubuntu9/functions
--- flash-kernel-3.104ubuntu8/functions	2022-04-03 17:32:44.000000000 +0000
+++ flash-kernel-3.104ubuntu9/functions	2022-04-18 11:13:13.000000000 +0000
@@ -470,13 +470,8 @@
 
 maybe_defrag() {
 	local file="$1"
-	local field="Bootloader-Has-Broken-Ext4-Extent-Support"
-	local broken_fw
 
-	if ! broken_fw=$(get_machine_field "$machine" "$field"); then
-	    return
-	fi
-	if [ "$broken_fw" != "yes" ]; then
+	if [ "$broken_ext4" != "yes" ]; then
 	    return
 	fi
 	if [ "$(df --output=fstype ${file} | sed -e 1d)" != "ext4" ]; then
@@ -832,6 +827,7 @@
 find_all_overlays() {
 	paths="/etc/flash-kernel/dtbs /usr/lib/linux-image-$kvers /lib/firmware/$kvers/device-tree/"
 	find $paths -name "*.dtbo" -o -name "overlay_map.dtb" 2>/dev/null | unique_filenames
+	find $paths -path "*/overlays/README" 2>/dev/null
 }
 
 find_pi_firmware() {
@@ -1072,6 +1068,7 @@
 boot_multi_path="$(get_machine_field "$machine" "Boot-Multi-Path")" || :
 android_boot_device="$(get_machine_field "$machine" "Android-Boot-Device")" || :
 android_skip_initrd="$(get_machine_field "$machine" "Android-Skip-Initrd")" || :
+broken_ext4="$(get_machine_field "$machine" "Bootloader-Has-Broken-Ext4-Extent-Support")" || :
 
 if [ -n "$dtb_append_from" ]; then
     if dtb_append_required; then
diff -Nru flash-kernel-3.104ubuntu8/test_functions flash-kernel-3.104ubuntu9/test_functions
--- flash-kernel-3.104ubuntu8/test_functions	2022-01-27 15:47:09.000000000 +0000
+++ flash-kernel-3.104ubuntu9/test_functions	2022-04-18 11:13:13.000000000 +0000
@@ -989,7 +989,9 @@
     (
         find() {
             saved_args="$@"
-            cat "$mock_find_output"
+            if [ "${saved_args##*README}" = "${saved_args%%README*}" ]; then
+                cat "$mock_find_output"
+            fi
         }
         . "$functions"
         expected="\