If you have some time spare, take a look at the 🇪🇺 standards that are currently in a mature draft state, awaiting feedback until end of February. I have started reading through requirements for bootloaders and operating systems.

All docs here:
https://docbox.etsi.org/CYBER/EUSR/Open

How to provide feedback:
https://docbox.etsi.org/CYBER/EUSR/Open/ETSI_Commenting_Guidelines_for_Open_Consultation_2026-01-14.pdf