Looking for Embedded Linux resources. I am a pretty experienced developer in both Linux applications and embedded development.  However in my latest job I am in charge of low level port, system admin and build management.  My experience in these areas are both a bit light and a bit out of date. (My how things change).  

Are there any readable books that would help complete my knowledge in these areas?   I have Mastering "Embedded Linux Programming" which is pretty good for what it covers, but am up in driver debug system configuration and wanting to get my skills up quickly.