radxa/rock-4c-plus: init

[RadxaYuntian]

Description of changes

• Add currently undocumented rockchip module. Right now only used internally by radxa module.
  Open to be shared with other consumers if there is a need. Documentation can follow afterwards when we see common patterns.
• Add support for ROCK 4C+

Things done

• Tested the changes in your own NixOS Configuration
• Tested the changes end-to-end by using your fork of nixos-hardware and
  importing it via <nixos-hardware> or Flake input

[Mic92]

Interesting approach, we can potentially have this also for other rockchip based boards.

[RadxaYuntian]

Yes and this is just a proof-of-concept. Once this PR is accepted I'll add additional devices from us.

[RadxaYuntian]

BTW if this and EFI boot chain was accepted, then we will need to worry about updating U-Boot for like RK3588 devices where upstream is moving fast with potential DTB changes. Such updating script can also be used in diskoExtraPostVM to reduce duplication.

The question is where should this script go? Main nixpkgs (since it is quite essential for the U-Boot packages there to be useful) or here?

[RadxaYuntian]

Need to rework tests now since we will have a lot more Arm devices coming: https://github.com/NixOS/nixos-hardware/blob/master/tests/flake.nix#L42-L48

I tried to run the test locally but it locked my computer up :/

[RadxaYuntian]

Just added rock-4c-plus to aarch64Systems for now. We can figure out how to refactor tests in another PR.

[RadxaYuntian]

Move unfree config to disko.nix so it is not loaded by default. This allow test to run.

[RadxaYuntian]

@msgilligan you might be interested.

[RadxaYuntian]

@kibiz0r reported that the original flake example does not build on system without binfmt enabled, which I assume is due to the U-Boot package (does Hydra not cache unfree package?). I also thought about what's happening next, and realized that I want an option to override the U-Boot package, so I can use packages from my nixpkgs fork while working on them.

So such option is added, and an example of overriding with cross built package is provided in the example flake. It is disabled by default since it requires knowledge of implementation detail to use, so normal users are recommended to configure binfmt instead.

[RadxaYuntian]

CI failed because NixOS/nixpkgs#361461 is not merged :/

[Mic92]

@mergify queue

[mergify]

queue

✅ The pull request has been merged automatically

The pull request has been merged automatically at d1f201f