of the file is zero modify mc1322x-load.pl to optionally send a zero length file with -z; extra data on the command line is still written. This allows you to burn the mac adress without flashing a vaild image.
based on commit aac3a355451d899f02737f2907af8c874ee4feba of git://git.devl.org/git/malvira/contiki-mc1322x.git