1. 根目录:
2. Documentation
3. networking
4. timestamping
5. Makefile

# kbuild trick to avoid linker error. Can be omitted if a module is built.
obj- := dummy.o

# List of programs to build
hostprogs-y := timestamping

# Tell kbuild to always build the programs
always := $(hostprogs-y)

HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include

clean:
	rm -f timestamping