linux

Three major phases
-BIOS
-Bootloader
-Kernel

The BIOS
Basic Input Output System(BIOS)
-The first program
-Runs from ROM
-OS independent

POST
-Power-on-self-test

Boot an OS from a storage device

-Proceed through the list until it finds a MBR

The boot loader

MBR

-First sector of the drive

Bootloader may reside in the MBR

-And/or may reside elsewhere

MBR runs the bootloader

– Bootloader loads the OS

-May be automatic or prompt for options

-LILO, GRUB

May create an initrd image

-“initial ramdisk”

-A RAM-based file system

Loading the linux kernel

Bootloader loads the kernel

-/boot/vmlinuz

-The kernel may be a compressed file

Gets the hardware running

-linuxrc

–linux run command

initrd ramdisk is dismounted

-let’s use the real disk!

File system is mounted

-kernel runs init