Official Debian support!

[foresto]

[code]#!/bin/sh

# This script installs RockPro64 devicetree files into /boot when new kernels
# are installed, removes them when kernels are removed, and updates the
# "dtbs" and "dtbs.old" symlinks accordingly.
# It should be copied into /etc/kernel/postinst.d/ and /etc/kernel/postrm.d/
# and given execute permission.

I have edited that post to contain the latest version of the script. It is now smart enough to create a new /boot/dtbs.old symlink when a kernel is removed and the existing dtbs.old becomes dtbs. (It uses the same logic as used for the other symlinks in /boot.)