anchor.diff:                        + " -drive if=pflash,format=raw,unit=1,file=$efiVars");
           }
           ''
  -          # Create a /boot EFI partition with 40M and arbitrary but fixed GUIDs for reproducibility
  +          # Create a /boot EFI partition with 60M and arbitrary but fixed GUIDs for reproducibility
             ${pkgs.gptfdisk}/bin/sgdisk \
               --set-alignment=1 --new=1:34:2047 --change-name=1:BIOSBootPartition --typecode=1:ef02 \
               --set-alignment=512 --largest-new=2 --change-name=2:EFISystem --typecode=2:ef00 \
  
positive.code: 
    drivesCmdLine = drives: concatStringsSep " " (imap1 driveCmdline drives);
  
    # Creates a device name from a 1-based a numerical index, e.g.
    # * `driveDeviceName 1` -> `/dev/vda`
    # * `driveDeviceName 2` -> `/dev/vdb`
  
negative.code:             ''
                mkdir $out
                diskImage=$out/disk.img
                ${qemu}/bin/qemu-img create -f qcow2 $diskImage "60M"
                ${if cfg.useEFIBoot then ''
                  efiVars=$out/EFI_VARS.fd
                  cp ${efiVars} $efiVars
  