RevPi Connect 5 + onboard TPM on balenaOS – device tree / overlay guidance?

[wooyay1]

Hi,
I’m running balenaOS on a RevPi Connect 5 and need the onboard TPM (SLB9670) to appear as /dev/tpm0 or /dev/tpmrm0. I configure boot settings through Balena (BALENA_HOST_CONFIG_dtoverlay).

I’ve added dtoverlay=tpm-slb9670 alongside vc4-kms-v3d-pi5. The tpm_tis_spi stack loads, but /sys/class/tpm stays empty and there are no TPM device nodes, which suggests the stock Pi tpm-slb9670 overlay doesn’t match the Connect 5 wiring.

Balena doesn’t appear to be planning dedicated RevPi 5 support, so we’re on a generic Pi-style image and need Kunbus’s guidance on how the onboard TPM should be described in device tree when not using the stock Revolution Pi OS—whether that’s a different overlay, parameters, or documentation / DTS reference.

Thanks for any pointers.

[wooyay1]

Replying to myself - I got it working...

Copy revpi-connect5.dtbo and dt-blob.bin from Revolution Pi debian image to /mnt/boot/overlays and /mnt/boot
Set dtoverlay=revpi-connect5 BEFORE dtoverlay=vc4-kms-v3d-pi5 in config.txt
dtparam=spi=off

Very hacky, but at least it works.