check

modules/nixos/hardware/raspberry-pi/default.nix

@@ -186,6 +186,11 @@ in
           useGenerationDeviceTree = lib.mkOverride 60 (if cfg.bootType == "uefi" then false else true);
         };
         systemd-boot.enable = (if cfg.bootType == "uefi" then true else false);
+        systemd-boot.extraInstallCommands = let 
+          bootloaderInstaller = (if cfg.bootType == "uefi" then (builder."uefi") else (builder."uboot")); # todo 
+        in ''
+          ${bootloaderInstaller} -f /boot/firmware -b /boot -c
+        '';
         grub.enable = lib.mkForce false;
       };
     };

modules/nixos/hardware/raspberry-pi/uefi-builder.sh

@@ -42,9 +42,8 @@ if [ -n "$fwtarget" ]; then
     @firmwareBuilder@ -c $default -d $fwtarget
 
     echo "copying uefi firmware..."
-    #for file in "@uefi@/*"; do
+    rm -rf $fwtarget/*
     copyForced @uefi@ $fwtarget/
-    #done
 fi
 
 echo "uefi bootloader installed"