A good Embedded GNU/Linux book

Hi guys,

I am looking for a good book about this subject. I found a couple of
books which seems interesting but I don't know which one buy:

Building Embedded Linux Systems -- by Karim Yaghmour
(Amazon.com product link shortened)/

or

Embedded Linux: Hardware, Software, and Interfacing -- by Craig Hollabaugh
(Amazon.com product link shortened)/

Which one do you recommend for a person with skills in programming,
kernel development, and GNU/Linux OS, but not in Embedded systems?

Neither of them talk in depth about GUI programming in Embedded systems.
Do you know another book with this doc?

I need your help. };-)

Thx in advance,
Regards!