Revert "schalter: remove"

This reverts commit c5ff918d44.

flake.nix

@@ -657,6 +657,38 @@
             ./hosts/rpi-netboot
           ];
           system = "aarch64-linux";
+
+        schalter = nixosSystem' {
+          modules = [
+            "${inputs.nixpkgs}/nixos/modules/installer/sd-card/sd-image-raspberrypi.nix"
+            ({ lib, ... }: {
+              networking.hostName = "schalter";
+              hardware.enableRedistributableFirmware = true;
+              #networking.wireless.enable = true;
+              powerManagement.cpuFreqGovernor = lib.mkDefault "performance";
+
+              boot = {
+                loader = {
+                  grub.enable = false;
+                  raspberryPi = {
+                    enable = true;
+                    version = 1;
+                    uboot.enable = true;
+                  };
+                };
+                # supportedFilesystems = lib.mkForce [ "vfat" "ext4" ];
+
+                tmpOnTmpfs = true;
+              };
+              sdImage = {
+                compressImage = false;
+                imageBaseName = "schalter";
+                firmwareSize = 512;
+              };
+
+            })
+          ];
+          system = "armv6l-linux";
         };
 
         matemat = nixosSystem' {