anchor.diff:              ''
                 mkdir $out
                 diskImage=$out/disk.img
  -              ${qemu}/bin/qemu-img create -f qcow2 $diskImage "40M"
  +              ${qemu}/bin/qemu-img create -f qcow2 $diskImage "60M"
                 ${if cfg.useEFIBoot then ''
                   efiVars=$out/EFI_VARS.fd
                   cp ${efiVars} $efiVars
  
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:                       + " -drive if=pflash,format=raw,unit=1,file=$efiVars");
          }
          ''
            # 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 \
  