Best links for study

ONBOOT
http://omappedia.org/wiki/Bootloader_Project
https://groups.google.com/forum/#!topic/beagleboard/M-ew_WGjE_A
http://elinux.org/Panda_How_to_MLO_%26_u-boot

Attr ANd Capabilities
https://bugzilla.redhat.com/show_bug.cgi?id=771927
https://bbs.archlinux.org/viewtopic.php?id=146269
https://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.2/capfaq-0.2.txt
http://www.markus-gattol.name/ws/udev.html

UDEV
http://www.signal11.us/oss/udev/
http://www.linux.com/news/hardware/peripherals/180950-udev
http://blog.csdn.net/acs713/article/details/8584392
http://blog.csdn.net/lqrensn/article/details/8097288
http://blog.csdn.net/jtli_embeddedcv/article/details/9316373
http://blog.csdn.net/skyflying2012/article/details/9359185

Best for OS
http://www.ece.cmu.edu/~ece548/handouts/