Comment 1 for bug 2038087

The problem is reproducible:

Create file /etc/flash-kernel/machine with content

   Raspberry Pi 400 Rev 1.0

on any arm64 system and run flash-kernel:

$ sudo flash-kernel $(uname -r)
Using DTB: bcm2711-rpi-4-b.dtb
Installing /lib/firmware/6.2.0-1013-raspi/device-tree/broadcom/bcm2711-rpi-4-b.dtb into /boot/dtbs/6.2.0-1013-raspi/./bcm2711-rpi-4-b.dtb
Taking backup of bcm2711-rpi-4-b.dtb.
Installing new bcm2711-rpi-4-b.dtb.
flash-kernel: installing version 6.2.0-1013-raspi

The following change is enough to fix the issue:
--- db/all.db 2023-06-22 14:18:53.000000000 +0000
+++ /usr/share/flash-kernel/db/all.db 2023-10-02 11:46:14.211402418 +0000
@@ -1823,7 +1805,7 @@
 Machine: Raspberry Pi 4 Model B Rev 1.2
 Machine: Raspberry Pi 4 Model B Rev 1.4
 Machine: Raspberry Pi 4 Model B Rev 1.5
-Machine: Raspberry Pi *
+Machine: Raspberry Pi 4 *
 Kernel-Flavors: raspi raspi-nolpae
 Method: pi
 DTB-Id: bcm2711-rpi-4-b.dtb