simple BeagleBone Black support by copying bonegreen

[Dridus]

wonderful project, thank you for it!

[lorenzleutgeb]

I have a BeagleBone Black and was trying to find out whether this project allows running NixOS on it. So I stumbled upon this PR. @Dridus can you comment on whether it works? Did you run it on a BeagleBone Black? Is there anything that needs special care?

[Dridus]

@lorenzleutgeb we do run NixOS on BBBs successfully, though in the end didn't need this project as mainline NixOS was sufficient. the only things that we know don't work are that it's still booting using the eMMC u-boot and not the one we flash onto the SD card, and that we don't have a working BBBw with wireless yet, though we haven't tried too hard.

here's roughly the nixos config we're using to build the image:

sd-image.nix:

let
  nixpkgsSrc = import ./nixpkgs.nix;
  nixos = import "${nixpkgsSrc}/nixos" {
    configuration = { ... }: {
      imports = [
        "${nixpkgsSrc}/nixos/modules/installer/cd-dvd/sd-image.nix"
        ./base.nix
        ./bbb.nix
      ];
    };
  };
in
  nixos.config.system.build.sdImage // {
    inherit (nixos) pkgs system config;
  }

nixpkgs.nix:

builtins.fetchTarball "https://github.com/VitalBio/nixpkgs/archive/d40e14d80afbfa5386f6b8bbacaaabba51462ed5.tar.gz"

base.nix:

{ config, ... }:
{
  imports = [ crosspkgs/modules ];

  system.stateVersion = "20.09";

  nixpkgs.overlays = [
    (self: super: {
      erlang = super.erlang.override { wxSupport = false; };
      gnupg = super.gnupg.override { guiSupport = false; };
      libnl = super.libnl.override { pythonSupport = false; };
      nmap  = super.nmap.override  { withLua = false; };
      polkit = super.polkit.override { withGnome = false; };
    })
  ];

  boot.loader.grub.enable = false;

  documentation = {
    info.enable = false;
    man.enable = false;
  };
  environment.noXlibs = true;
  i18n = {
    defaultLocale = "en_US.UTF-8";
    supportedLocales = [ (config.i18n.defaultLocale + "/UTF-8") ];
  };
  networking.firewall.enable = true;
  programs.command-not-found.enable = false;
  security = {
    polkit.enable = false;
    audit.enable = false;
  };
  services.udisks2.enable = false;
}

bbb.nix:

{ lib, config, pkgs, ... }:
{
  config = {
    nixpkgs.crossSystem = lib.systems.elaborate {
      system = "armv7l-linux";
      platform = lib.systems.platforms.beaglebone // {
        kernelBaseConfig = "omap2plus_defconfig";
      };
    };

    boot = {
      kernelPackages = pkgs.linuxPackages_5_4;
      kernelParams = ["console=ttyS0,115200n8"];
    };

    sdImage = {
      compressImage = false;

      populateFirmwareCommands =
        let
          uboot = pkgs.buildUBoot {
            defconfig = "am335x_evm_defconfig";
            extraMeta.platforms = ["armv7l-linux"];
            filesToInstall = ["MLO" "u-boot.img"];
          };
        in ''
          cp ${uboot}/MLO firmware/MLO
          cp ${uboot}/u-boot.img firmware/u-boot.img
        '';

      populateRootCommands = let
        inherit (config.system.build) toplevel;
      in ''
        mkdir -p ./files/boot/extlinux
        mkdir -p ./files/boot/dtbs

       cp $dtbDir/am335x-boneblack.dtb ./files/boot/dtbs

        cat > ./files/boot/extlinux/extlinux.conf <<EOF
        DEFAULT vital-device
        MENU TITLE ------------------------------------------------------------
        TIMEOUT 1
        LABEL vital-device
        MENU LABEL Vital Device
        LINUX ../kernel
        INITRD ../initrd
        FDTDIR ../dtbs
        APPEND systemConfig=${toplevel} init=${toplevel}/init $(cat ${toplevel}/kernel-params) dyndbg="file pinctrl-single.c +p; file drivers/pinctrl/core.c +p"
        EOF

        cp ${toplevel}/kernel ./files/boot/kernel
        cp ${toplevel}/initrd ./files/boot/initrd
      '';
    };

    hardware.leds = [
      "beaglebone:black:heartbeat"
      "beaglebone:black:mmc0"
      "beaglebone:black:usr2"
      "beaglebone:black:usr3"
    ];
  };
}

and built with nix build -f sd-image.nix

note that we use a somewhat different configuration with custom devicetrees to reconfigure the pinmux etc, so I had to adapt this a bit and it may not work if I flubbed that edit

[Dridus]

closing as this is old and I don't want it to clutter my PR list