android工程的编译过程
http://bbs.pediy.com/showthread.php?t=163672

makefile 分析
整个makefile都需要parse。
parse完，有了所有的依赖关系，再根据指定目标来确定哪些需要remake。
make xxx -dpn观察。
-n是不真正执行命令。
 make -j8 bootimage -dp 2>&1 | tee /media/disk2/bootimage.log3.txt

What's the difference of `./configure` option `--build`, `--host` and `--target`
http://stackoverflow.com/questions/5139403/whats-the-difference-of-configure-option-build-host-and-target

kernel
https://www.ibm.com/developerworks/community/blogs/5144904d-5d75-45ed-9d2b-cf1754ee936a/entry/kernel-build-system?lang=en
http://lwn.net/Articles/21835/
https://www.kernel.org/doc/Documentation/kbuild/modules.txt
https://www.kernel.org/doc/Documentation/kbuild/makefiles.txt
http://stackoverflow.com/questions/8320955/how-does-the-kernel-makefile-magically-knows-what-to-compile
http://www.linuxjournal.com/article/6568