Add host drain

hosts/drain/build-sd-image.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+nix build -f "<nixpkgs/nixos>" config.system.build.sdImage -I nixos-config=configuration.nix -I nixpkgs=channel:nixos-unstable --system aarch64-linux

hosts/drain/configuration.nix

@@ -0,0 +1,34 @@
+{ lib, pkgs, config, modulesPath, ... }:
+
+{
+  imports = [
+    ../../configuration/common
+    (modulesPath + "/installer/cd-dvd/sd-image.nix")
+  ];
+
+  boot.loader.grub.enable = false;
+  boot.loader.raspberryPi.enable = true;
+  boot.loader.raspberryPi.version = 4;
+  boot.kernelPackages = pkgs.linuxPackages_rpi4;
+
+  sdImage = {
+    firmwareSize = 1024;
+    firmwarePartitionName = "NIXOS_BOOT";
+    populateFirmwareCommands =
+      "${config.system.build.installBootLoader} ${config.system.build.toplevel} -d ./firmware";
+    populateRootCommands = "";
+  };
+
+  fileSystems."/boot/firmware" = {
+    mountPoint = "/boot";
+    neededForBoot = true;
+  };
+
+  documentation.enable = false;
+
+  networking.hostName = "drain";
+
+  networking.interfaces.eth0.useDHCP = true;
+
+  system.stateVersion = "21.03";
+}