System Initialization

In the boot process, the transfer from the kernel phase (the loading of the kernel, probing for devices, and loading drivers) to init is indicated by the following lines:
INIT: version 2.78 booting
Welcome to Red Hat Linux
The init program, part of the SysVinit RPM package, is now in control. Known as “the father of all processes,” the output from ps always lists init as PID (process identifier) 1. Its actions are directed by the /etc/inittab file, which is reproduced next.

The following text shows the contents of the /etc/inittab file as it is delivered with Red Hat Linux:
#
# inittab This file describes how the INIT process should set up
the system in a certain run level.
#
# Author: Miquel van Smoorenburg,
# Modified for RHS Linux by Marc Ewing and Donnie Barnes
#
# Default runlevel. The runlevels used by RHS are:
# 0 − halt (Do NOT set initdefault to this)
# 1 − Single user mode
# 2 − Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 − Full multiuser mode
# 4 − unused
# 5 − X11
# 6 − reboot (Do NOT set initdefault to this)
#
id:3:initdefault:
# System initialization.
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc 0
l1:1:wait:/etc/rc.d/rc 1
l2:2:wait:/etc/rc.d/rc 2
l3:3:wait:/etc/rc.d/rc 3
l4:4:wait:/etc/rc.d/rc 4
l5:5:wait:/etc/rc.d/rc 5
l6:6:wait:/etc/rc.d/rc 6
# Things to run in every runlevel.
ud::once:/sbin/update
.
.
.
# Run xdm in runlevel 5
# xdm is now a separate service
x:5:respawn:/etc/X11/prefdm −nodaemon