The very limited resources of the cc65 target machines now and then require
manual optimization of the build process by compiling individual source files
with different compiler options. GNU Make offers
Target-specific Variable Values
perfectly suited for doing so. For example placing the code of the two modules
foo and bar in the segment FOOBAR can be archived with this
target-specific variable definition:
foo.o bar.o: CFLAGS += --code-name FOOBAR