remake after changing Makefile

[Vitus Jensen]

Hej!

As my first steps had only the intention to get anything at all from newlib,
I didn't pay attention to how the libs were build.  OK, now I have a lib and
need to modify <build dir>/Makefile to change compiler options and add
defines.
After editing that Makefile, how do I force make to recreate the makefiles
in all other directories like it did in the first run?  "make clean" isn't the
answer, it only deletes object code.

Bye,
   Vitus