add separate root nix disko config

disks/root.nix

@@ -0,0 +1,44 @@
+{ disks, ... }: {
+  disk = {
+    boot = {
+      type = "disk";
+      device = builtins.elemAt disks 0;
+      content = {
+        type = "table";
+        format = "gpt";
+        partitions = [
+          # Boot partition
+          {
+            type = "partition";
+            name = "ESP";
+            start = "0";
+            end = "512MiB";
+            fs-type = "fat32";
+            bootable = true;
+            content = {
+              type = "filesystem";
+              format = "vfat";
+              mountpoint = "/boot";
+              extraArgs = [ "-n boot" ];
+            };
+          }
+          # Root partition ext4
+          {
+            type = "partition";
+            name = "root";
+            start = "512MiB";
+            end = "100%";
+            part-type = "primary";
+            bootable = true;
+            content = {
+              type = "filesystem";
+              format = "ext4";
+              mountpoint = "/";
+              extraArgs = [ "-L nixos" ];
+            };
+          }
+        ];
+      };
+    };
+  };
+}

flake.nix

@@ -153,6 +153,7 @@
       };
 
       diskoConfigurations = {
+        root = import ./disks/root.nix;
         swan = { ... }: (import ./hosts/swan/disks.nix { }).disko.devices;
       };