To force makefile system to build makedep you should add to your config.mak
file (if there isn't yet such a line):

DEPEND_TOOL=mkdep

When you'll do "make depend" the makedep tool will be built prior to creating
dependencies. Alternatively if you build the makedep executable (by typing
"make mkdep") and install somewhere in your system, you can add instead:

DEPEND_TOOL.INSTALLED = yes

This will not force building the mkdep tool, but will force the usage of it.
