hcloud: add arm subprofile (#214)

dev/test-configurations.nix

@@ -57,6 +57,16 @@ in
       }
     ];
   };
+  example-hardware-hetzner-cloud-arm = nixosSystem {
+    inherit system;
+    modules = [
+      dummy
+      srvos.nixosModules.hardware-hetzner-cloud-arm
+      {
+        systemd.network.networks."10-uplink".networkConfig.Address = "::cafe:babe:feed:face:dead:beef";
+      }
+    ];
+  };
   example-hardware-vultr-bare-metal = nixosSystem {
     inherit system;
     modules = [

docs/nixos/hardware.md

@@ -16,6 +16,12 @@ Hardware configuration for <https://www.hetzner.com/cloud> instances.
 
 The main difference here is that cloud-init is enabled.
 
+### `nixosModules.hardware-hetzner-cloud-arm`
+
+Hardware configuration for <https://www.hetzner.com/cloud> arm instances.
+
+The main difference from `nixosModules.hardware-hetzner-cloud` is using systemd-boot by default.
+
 ### `nixosModules.hardware-hetzner-online-amd`
 
 Hardware configuration for <https://www.hetzner.com/dedicated-rootserver> bare-metal AMD servers.

nixos/default.nix

@@ -40,6 +40,7 @@ exposeModules ./. [
   ./desktop
   ./hardware/amazon
   ./hardware/hetzner-cloud
+  ./hardware/hetzner-cloud/arm.nix
   ./hardware/hetzner-online/amd.nix
   ./hardware/hetzner-online/intel.nix
   ./hardware/hetzner-online/ex101.nix

nixos/hardware/hetzner-cloud/arm.nix

@@ -0,0 +1,13 @@
+{
+  imports = [
+    ./.
+  ];
+
+  config = {
+    # arm uses EFI, so we need systemd-boot
+    boot.loader.systemd-boot.enable = true;
+    boot.loader.timeout = 30;
+    # since it's a vm, we can do this on every update safely
+    boot.loader.efi.canTouchEfiVariables = true;
+  };
+}