If you want a Makefile to generate bitmap fonts in advance, instead of
generating them on the fly with MakeTeXPK, take a look at Makefile.gf in
this directory.

Or you can try the following minimal shell script:

#!/bin/sh
if test $# -eq 0; then
  files=`echo *[0123456789].mf`
else
  files="$*"
fi
for f in $files; do
  echo $f...
  mf '\mode:=ljfour; input '$f
  gf_file=`basename $f .mf`.600gf
  test -r $gf_file && gftopk $gf_file
done
