It's pretty easy. You can create two files in this directory to tweak
settings: pre-config.make and config.make.
-pre-config.make is included before $(PLATFORM).make and
+pre-config.make is included before $(BUILD_PLATFORM).make and
$(PROFILE).make, so you can set either of these variables if you want
to change the default.
Just about any other change should go in config.make, which is
-included after $(PLATFORM).make and $(PROFILE).make, so you can use
+included after $(BUILD_PLATFORM).make and $(PROFILE).make, so you can use
the values defined in those files if you wish. For example,
MCS_FLAGS = $(DEFAULT_MCS_FLAGS) /my-experimental-optimizer-flag