我借鉴的是u-boot版本号为2012.04.01 这个可以在UBOOT的主Makefile中查到，kernel版本号为3.4.20 。两个都可以。以u-boot为例，打开u-boot目录下的lib目录，我们可以看到有crc7,16,32,md5等等，我们的目标是rbtree.c。我们把这个文件打开看看
/*
Red Black Trees
(C) 1999 Andrea Arcangeli <andrea@suse.de>
(C) 2002 David Woodhouse <dwmw2@infradead.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.