There is an Ethernet connection on the back of the controller module

It’s postulated that this thing’s controller can run doom, and apparently they can be purchased separately, although what controller exactly is not specified.

https://www.reddit.com/r/linux/comments/k0z196/my_boiler_runs_linux_on_its_touchscreen_controller/

https://www.manualslib.com/manual/790246/Ibc-Technologies-Sl-20-115.html