Device Detection

http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html
http://blog.roodo.com/use_the_force/archives/6296305.html
http://blog.csdn.net/absurd/archive/2007/05/03/1595625.aspx
http://freedesktop.org/wiki/Software/hal
http://zh.wikipedia.org/wiki/Sysfs
http://www.linuxfromscratch.org/lfs/view/stable/chapter07/udev.html


In 2.6 kernel, the system use sysfs/udev for the device detection.
1. When device is inserted to the system, the sysfs will first create for the device to provide the device information.
2. Kernel generate uevent through netlink to notify user space
3. udevd parse the info and create device node, and to load driver