This project enables bootc based images to be booted on Raspberry Pi based hardware without needing UEFI chainloaders.
- The chainloaders don't usually have support for proper devicetree initialization on the pi's without someone self assembling single devicetree files from the overlays for specific boards making them hard to support.
- Support for the newest hardware often lags significant amounts of time. PI5's still don't have reliable support years after release.
- They also lack support for some of the special features of the firmware such as the RPI tryboot mechanism and hardware buttons on the PI header
Run bootc switch or bootc update as normal
Tryboot:
The tryboot feature is enabled with writing TRYBOOT=1 to /etc/rpi-bootc-bootloader/tryboot.conf
Switch image as normal, but without apply. When ready to apply, run rpi-bootc-bootloader tryreboot
This will cause the RPI to boot the currently staging bootc image on the next boot. Failure to boot or a power cycle should return it automatically to the current, working image.
Once the boot is successful and you are happy with it, run rpi-bootc-bootloader sync to update the default to the current image.
To support manually selecting the previous image to boot, we need to add a push button to the RPI header. Connect it to GPIO pin 6 (PI header pin 31), and ground, easiest is PI header pin 39. No resisters are needed.
To fall back to the previous image, simply hold in the button while booting.
There is a work in progress project in the works to support using a RPI Zero 2 W as a BMC for a RPI5.
This includes:
- Remote serial console access
- Remote bootc mode switching
- Remote power control
- Some communication between the host and BMC without using USB ports
Grab a case like:
And a 12mm button like:
Start with the front plate:
Measure ~0.5 inches from the top and from the closest usb cutout. Drill a 12mm hole centered at that point.
Add optional mounting rail if you want to rack mount it, fit the button through the hole and secure with the nut that comes with the button:
Use a crimper and attach a Dupont 1x5 Connector
Crimp on the pins
Slip on the connector
