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Installing NixOS on BTT PI

Published: 2024-01-20

BigTreeTech Pi is a special-purpose board that is similar to Orange Pi zero2 (it has the Allwinner H616), but built for 3d printers. I'll be using it for a 3d printer, but I also wanted to use nixos to manage it. This is what I tried to get it to work. Ultimately, I gave (for now?). So if you're looking for how to get it running, the princess is in another castle. Sorry.

First attempt

First I tried to use normal nixos firmware from NixOS on ARM wiki page.

sudo dd if=/path/to/nixos-sd-image-....img of=/dev/sdX status=progress

This obviously did not work. Since I couldn't find a good documented way of building a custom image with u-boot I gave up after some short experimentation. This is what you get for using weird SBCs...

Next, I tried the image from katyo/nixos-arm which did not work either.

Custom u-boot

# flake.nix
{
  description = "U-Boot stuffs";
  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-23.11";
  outputs = inputs:
    with (import inputs.nixpkgs {
      system = "aarch64-linux";
    }); {
      devShells.aarch64-linux.default = mkShell {
        buildInputs = [
          gnumake
          gcc
          bison
          flex
          (python3.withPackages (ps: with ps; [setuptools]))
          swig
          openssl_3_1
          ncurses
          dtc
        ];
      };
    };
}

nix develop # dependencies

git clone https://github.com/ARM-software/arm-trusted-firmware.git
cd arm-trusted-firmware
git checkout 57410eebe697546e4d66f5b70acbc68131b28cb1
make PLAT=sun50i_h616 DEBUG=1 bl31
cd ..

export SCP=/dev/null # I don't need suspend
export BL31=$PWD/arm-trusted-firmware/build/sun50i_h616/debug/bl31.bin
git clone git://git.denx.de/u-boot.git
cd u-boot
git checkout v2024.01
make orangepi_zero2_defconfig
make

U-boot's board/sunxi/README.sunxi64 might be of interest to you.

flake.lock
{
  "nodes": {
    "nixpkgs": {
      "locked": {
        "lastModified": 1705641746,
        "narHash": "sha256-D6c2aH8HQbWc7ZWSV0BUpFpd94ImFyCP8jFIsKQ4Slg=",
        "owner": "nixos",
        "repo": "nixpkgs",
        "rev": "d2003f2223cbb8cd95134e4a0541beea215c1073",
        "type": "github"
      },
      "original": {
        "owner": "nixos",
        "ref": "nixos-23.11",
        "repo": "nixpkgs",
        "type": "github"
      }
    },
    "root": {
      "inputs": {
        "nixpkgs": "nixpkgs"
      }
    }
  },
  "root": "root",
  "version": 7
}

What I think is the reason for those attempts not working is that BTT Pi is not close enough to the Orange Pi Zero2 for the configs to work. But since I do not know if my attempts work on orange pi, I decided to scrap it and try something different. I might revisit this approach if at some point I'm trying to setup some next SBC and then I might have enough experience to get it working on this weird board...

Plan C: kexec

Plan C: nixos-anywhere.

First, I flashed the oficial minimal image:

sudo dd if=.../CB1_Debian11_minimal_kernel5.16_20230712.img of=/dev/sda status=progress bs=1M oflag=direct,sync

then I kexec'd nixos

curl -L https://github.com/nix-community/nixos-images/releases/download/nixos-unstable/nixos-kexec-installer-noninteractive-aarch64-linux.tar.gz | tar -xzf- -C /root

That did not work. I don't know why, but it might be because they call for 1.5G of RAM and this board only has 1. Oh well.

Conclusion

I learned a bit, but ultimately failed. Next time I'll be getting a board that has better mainline support. I naively thought if a SOC has good support and I don't need any extra SBC stuffs it'll work. Well, I was wrong. To my defense, this one was included in the kit of the printer.

It still works with the included armbian-based? image, so at least it's not going to the bin.

References