Tracking: Kernel/Device-tree additions for custom hardware of `spirit-cm5-phone`

[tym2k1]

Goal

As stated in motivation the goal of this repository is to provide a minimal, reproducible base image with the kernel, device tree, and low-level configuration required to boot the SPIRIT phone and enable downstream distributions.

This issue serves as a parent tracker for all kernel and device-tree work required to support custom SPIRIT hardware.
Not every contributor will have access to the full device, but people with individual components or development boards are encouraged to test and submit patches.

Resources

Relevant recipe: recipes-kernel/linux/linux-raspberrypi_%.bbappend. It's possible more will need to be added at some point.

Kernel

• Yocto Project Linux Kernel Development Manual
  • For the spirit-phone-cm5 target we're utilizing linux-raspberrypi recipe from the meta-raspberrypi layer. This greatly reduces workload and maintanance burden as we only need to append the required changes and overrides.

Device Tree

• Device Tree Basics
• Device Tree Specification Releases
  • Similarly right now the Device Tree is based on raspberrypi/linux/blob/rpi-6.12.y/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts and appended accordingly within the layer. For minimal image this seems to be working but the raspberrypi/linux seems to contain more CM5 specific dtsi additions that perhaps might need to be included in some way in the final configuration.

How to Contribute

• Pick a hardware sub-issue or open a new one for missing components.
• Develop/test your changes (even partial bring-up is valuable).
• Submit patches or pull requests referencing this parent issue.

Note:
If a kernel addition is not required for boot, build it as a module (=m).
If the device cannot boot properly without it, build it into the kernel (=y).

EDIT: Add DTS Specification Releases Link

[anchored-archer]

Device tree bindings:
https://www.kernel.org/doc/Documentation/devicetree/bindings/