MakefileΪ3:
1. Ŀ¼Makefile
2. Ŀ¼Makefile.build
3. Ŀ¼Makefile

һĿ¼Makefile
   򵥣ʽ£
obj-y += file.o
obj-y += subdir/
   
   "obj-y += file.o"ʾѵǰĿ¼µfile.c
   "obj-y += subdir/"ʾҪsubdirĿ¼ȥѰļЩļsubdirĿ¼µMakefile

ע: "subdir/"еб"/"ʡ

Ŀ¼Makefile
   ˶obj-yָĿ¼ҪȥļĿ¼⣬ҪǶ幤Ӳļexportĸ

Ŀ¼Makefile.build
   ӵĲ֣ĹܾǰĳĿ¼Ŀ¼СҪȥļΪbuilt-in.o
   ϸĽ뿴Ƶ

ġôʹMakefile
1ѶMakefile, Makefile.buildĶĿ¼
2޸ĶMakefile
2.1 ޸Ĺ
2.2 ޸ıѡѡ
2.3 ޸obj-yĿ¼ЩļЩĿ¼
2.4 ޸TARGETָĳ

3. ڸһĿ¼¶һMakefileʽΪ
obj-y += file1.o
obj-y += file2.o
obj-y += subdir1/
obj-y += subdir2/

4. ִ"make"룬ִ"make clean"ִ"make distclean"
   
   