modify initrd in Linux

http://www.thegeekstuff.com/2009/07/how-to-view-modify-and-recreate-initrd-img/

http://www.alexonlinux.com/opening-and-modifying-the-initrd#changing_it

http://www.cyberciti.biz/tips/compiling-linux-kernel-26.html

http://ubuntuforums.org/showthread.php?t=1843448

http://comments.gmane.org/gmane.linux.redhat.release.rhel6/345