Settings.System 和 SystemProperties
如何控制Android不锁屏
http://www.linuxidc.com/Linux/2010-11/30169.htm
ps:里面有介绍存储相关属性的文件位置
frameworks/base/packages/SettingsProvider/src/com/Android/providers/settings/DatabaseHelper.java
frameworks/base/packages/SettingsProvider/res/values/defaults.xml
给android添加系统属性：Settings.system和SystemProperties
http://blog.csdn.net/k1102k27/article/details/7106124
ps:一篇较浅显的文章
