Startup of Linux Systems

A. Boot steps and GRUB

1 Linux START process analysis                                                                                                          

( 1 ) BIOS Self-Test

l hardware detection and initialization

l Boot boot Device

( 2 ) boot boot device

l floppy disk ( first sector of 0 tracks)

l disc (outermost storage track)

l Hard Disk ( MBR)

l USB Storage Devices

( 3 ) Call Linux bootloader to In-memory

l Linux Boot program can use Grub/lilo and other boot software

l Grub/lilo can be installed in theboot sector of the MBR/boot partition

( 4 ) Run Linux Kernel

l The kernel is placed in the/boot directory, andLinux systems can support multiple versions of the kernel at the same time

l Unzip the kernel

l Detecting Hardware

l loading The root file system

( 5 ) Execution Init Process ( Press "I" to run one step )

l start a new process or close a process

l Select startup Mode

l set up a virtual terminal

( 6 ) User Login

l Enter user name and password

l To load a user configuration file

l loading shell programs

2 . Creation of the boot disk

Method One : Created during installation

method Two:Mkbootdisk

#mkbootdisk--device/dev/fd0 2.4.20-8

Method Three: using the DD command

# dd If=/boot/vmlinuz of=/dev/fd0

3 . GRUB

( 1 ) GRUB Introduction

GRUB is a powerful boot loader based on the Intel platform

( 2 ) GRUB features

l support for large hard drives, breaking through the limits of the above-surface cylinders

l supports two interface types ( menu, command line )

l Boot Screen

(3) Installing GRUB

l Install packages

#rpm –IVH grub-0.934.i386.rpm

l installing using the Install command GRUB to MBR

#grub

Grub>root (Hdx,y)

Grub>setup (Hdx[,y])

( 4 ) GRUB the configuration

#vi/boot/grub/grub.conf

grub.conf The configuration commands that are commonly used are:

default= menu item Ordinal /saved

Set the default startup item for the boot menu

Hiddenmenu

Hide Menu Interface

splashimage = image file full path name

Specify a file as the background image of the boot menu

timeout= number of seconds delayed

Set startup delay for Start menu

title menu Item Name

Start the configuration of a menu item, set the name of the menu item

Root (Hdx,y)

Set GRUB root device is the partition where the Linux kernel resides

Kernel Kernel file name

Specify the name of the kernel file and the parameters required to load the kernel

initrd initrd file name

Specify the location of the image file

Map (Hdx[,y]) (Hdx[,y])

Establish virtual disks

Rootnoverify (Hdx,y)

Specify the location of the Windows startup bootstrapper

Makeactive

Identifies the specified partition as the active partition

Chainloader +n/ file name

invoking the specified Windows startup file

Password Password /--MD5 Password redaction

Set GRUB boot Menu and menu item password

Lock

using the global Password lock menu item set by password

Savedefault

Saves the current Startup menu item as the default startup

File instance:

# grub-md5-crypt(Generate password for MD5 ciphertext)

# vi/etc/grub.conf

Default=0

Timeout=50

Splashimage= (hd0,0)/grub/splash.xpm.gz

Password--md5 #!dfdasdf34123!#@$!#@

Title RedHat Linux 9.0

Root (hd0,2)

Kernel/vmlinuz-2.4.20-8 ro root=/label=/

Initrd/initrd-2.4.20-8.img

Password Linux

Tile Windows 2000

Rootnoverify (hd0,0)

Chainloader +1

Lock

( 5 ) GRUB of the FAQ

l use of edit mode

option to temporarily modify the menu, in the menu interface by pressing E key to enter

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Menu Main interface

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Edit mode

l use of command-line mode

using command-line commands to set GRUB, press the C key in the menu interface to enter

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Command mode

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