You can create a library with mkmk by following this example. Create a .bf file, bye.bf, that calls the Library macro, putting the following information:
Library(ciao.a)
Type make merge.
host% make merge /<work_dir>/build-MYCOMP/src/ciao/bye.bf -> \ /tmp/MYSRC/MYCOMP/src/bye/bye.bf merged tree installed in /tmp/WORK/build-MYCOMP
This library will automatically include the list of object files given by getExport.