fix: create derivation for initrd creation

flake.nix

@@ -26,9 +26,9 @@
             echo "make UKI..."
 
             mkdir -p patos/efi/boot
-            ${self.packages.${system}.systemd.out}/usr/bin/ukify build \
-            --linux ${self.packages.${system}.kernel.kernel}/bzImage \
-            --initrd ./initrd.xz \
+            ${patosPkgs.systemd.out}/usr/bin/ukify build \
+            --linux ${patosPkgs.kernel.kernel}/bzImage \
+            --initrd ${patosPkgs.initrd.out}/initrd.xz \
             --cmdline "console=ttyS0" \
             -o patos/efi/boot/bootx64.efi
           '';
@@ -38,8 +38,8 @@
           systemd = pkgs.callPackage ./systemd { };
           dbus-broker = pkgs.callPackage ./dbus-broker { };
           rootfs = pkgs.callPackage ./rootfs { inherit patosPkgs; };
+          initrd = pkgs.callPackage ./rootfs/mkinitrd.nix { inherit patosPkgs; };
 
-          mkinitrd = pkgs.callPackage ./utils/mkinitrd.nix { inherit patosPkgs; };
           qemu-uefi-tpm = pkgs.callPackage ./utils/qemu-uefi-tpm.nix { };
         };