Radxa CM3 screen resolution

Hi people,

So, we got an ROCK 3 Compute Module running ubuntu 20.04, this connects with an HDMI screen. For this is wanted a specific resolution that remains persistent between reboots.

What are the options, without using a script with xrandr or so? Is there something specific that can be placed within a configuration file for at boot time?

I am currently using this:
~/.config/autostart/d_c.desktop
[Desktop Entry]
Type=Application
Name=d_c
Exec=/home/rock/d_c.sh

~/d_c.sh
touch ~/.Xauthority
xauth generate :0 . trusted
xauth add ${HOST}:0 . $(xxd -l 16 -p /dev/urandom)
export DISPLAY=:0
xrandr --newmode “1024x600_60.00” 49.00 1024 1072 1168 1312 600 603 613 624 -hsync +vsync
xrandr --addmode HDMI-1 “1024x600_60.00”
xrandr --output HDMI-1 --mode “1024x600_60.00”

It is working, but is not what I would call a solution.
What does radxa have that can be used?
Is there a proper solution?

Thank you,
Regards,
Thomas.