We have designed a custom RPI CM4-based carrier board, which we will be receiving the first prototype units in a few weeks. The manufacturer will be providing us with a Yocto Dunfell BSP layer with the carrier board, which reflects our custom hardware configuration - which inculdes relays, ADCs, RS232, RS485, etc. in addition to the CM4 module.
We are planning to create a custom Balena build to support this carrier, and I’ve been familiarizing myself with the Yocto environment in the meanwhile. I’ve managed to get it working under WSL2, and have been able to successfully build the Balena RPI images from scratch. Now I’d like to create my own board, and am looking for some guidance (I’ve already read the custom build doc at balenaOS - Docs):
- Since this is a CM4 module, should I be starting with the balena-raspberrypi repository? If so, how do I incorporate my BSP layer into that build? It seems to already incorporate the meta-raspberrypi BSP, though that does not seem to cover the CM4.
- Once I create and build a custom image, am I required to commit this to the public Balena repositories to be able to create and download images for my hardware from Balena Cloud similar to what I do for standard hardware? Is there any way to make those images only available to my team?
Any guidance would be appreciated, as I couldn’t find information on these topics in the public docs.