Novell LINUX ENTERPRISE DESKTOP 11 - ADMINISTRATION GUIDE 17-03-2009 Administration Manual page 90

information about GRUB, the Linux boot loader, can be found in
Boot Loader GRUB
3. Kernel and initramfs
kernel and an initial RAM–based file system (initramfs) into memory. The contents
of the initramfs can be used by the kernel directly. initramfs contains a small exe-
cutable called init that handles the mounting of the real root file system. If special
hardware drivers are needed before the mass storage can be accessed, they must
be in initramfs. For more information about initramfs, refer to
"initramfs"
4. init on initramfs
proper root file system, like providing kernel functionality for the needed file
system and device drivers for mass storage controllers with udev. After the root
file system has been found, it is checked for errors and mounted. If this has been
successful, the initramfs is cleaned and the init program on the root file system is
executed. For more information about init, refer to
(page 79). Find more information about udev in
Device Management with udev
5. init
providing different functionality. init is described in
(page 81).
9.1.1 initramfs
initramfs is a small cpio archive that the kernel can load to a RAM disk. It provides a
minimal Linux environment that enables the execution of programs before the actual
root file system is mounted. This minimal Linux environment is loaded into memory
by BIOS routines and does not have specific hardware requirements other than sufficient
memory. initramfs must always provide an executable named init that should execute
the actual init program on the root file system for the boot process to proceed.
Before the root file system can be mounted and the operating system can be started,
the kernel needs the corresponding drivers to access the device on which the root file
system is located. These drivers may include special drivers for certain kinds of hard
drives or even network drivers to access a network file system. The needed modules
for the root file system may be loaded by init on initramfs. After the modules are loaded,
udev provides the initramfs with the needed devices. Later in the boot process, after
78 Administration Guide
(page 93).
To pass system control, the boot loader loads both the
(page 78).
This program performs all actions needed to mount the
init handles the actual booting of the system through several different levels
Section 9.1.2, "init on initramfs"
Chapter 13, Dynamic Kernel
(page 145).
Section 9.2, "The init Process"
Chapter 10, The
Section 9.1.1,