1.load bios(hardware information)
2.read MBR's config to find out the OS
3.load the kernel of the OS
4.init process starts..
5.execute /etc/rc.d/sysinit
6.start other modules(etc/modules.conf)
7.execute the run level scripts （启动/etc/rc0.d或rc1.d或rc2.d……）
NFS:Network File System
8.execute /etc/rc.d/rc.local
9.execute /bin/login
10.shell started..
bty: rc.d is the directory for all run control daemons.
daemons are system services, usually running in the background.
rc意即run commands，d是daemons的意思