Add installer image package

flake.nix

@@ -76,6 +76,22 @@
       '';
 
       installer-iso = inputs.self.nixosConfigurations.installer.config.system.build.isoImage;
+
+      installer-image = nixos-generators.nixosGenerate {
+        system = system;
+        specialArgs = {
+          pkgs = pkgs;
+          diskSize = 20 * 1024;
+        };
+        modules = [
+          # Pin nixpkgs to the flake input, so that the packages installed
+          # come from the flake inputs.nixpkgs.url.
+          ({ ... }: { nix.registry.nixpkgs.flake = nixpkgs; })
+          # Apply the rest of the config.
+          ./machines/installer-image
+        ];
+        format = "raw-efi";
+      };
     });
 
     apps = forAllSystems (system: {