Happy to report my idea worked. Setup is as follows:
- Common base DTS file with all hardware defined. Items unique to one or the other configuration are disabled by default.
- Created a pair of DTS files that change the status for each variant’s additional hardware to “okay”.
- Build these into dtbo files using
dtc - Place the dtbos in usr/lib/modules/[version]/dts/overlays
- Add a systemd script that checks the contents of overlays.txt matches the hardware (we use some GPIO strapping to do this). If not, rewrite the .txt and issue a reboot.
- Can be easily expanded with additional variants/hardware revisions if necessary.
Something similar can be done with uboot scripts as well but this is far easier and can be done directly via torizoncore-builder.