Linux booting process can be divided to multiple stages. In simple terms the bios loads and executes the master boot record.
The bios integrity check post.
Boot process steps in linux. In this article i am explaining the linux booting process with bios as the. Since init was the 1st program to be executed by linux kernel it has the process id pid of 1. The boot process is usually initialized when a user presses the power on button if.
Initrd is used by kernel as temporary root file system until kernel is booted and the real root file system is mounted. The linux boot process or any other boot process for that matter is a sequence of events that eventually leads to loading up your pc so that you can access the operating system. Stages of linux booting process explanation step by step tutorial step 1.
Mbr stands for master boot record and is responsible for loading and executing the grub boot loader. Do a ps ef grep init and check the pid. It is the most crucial segment.
Bios stands for basic input output system. The ignition switch of a pc. A basic guide to linux boot process 1.
After that linux kernel which you selected to boot from loads initrd initial ramdisk the initrd is used by the linux kernel as a temporary filesystem in the memory it contains tools and kernel modules which will continue the boot process including mounting a virtual root file system temporarily. Bios basic input output system. Understanding the boot process will help you understand how the hardware and software is working together and also will give you the required information to begin troubleshooting a booting problem you have.
This can be considered the heart of operating. Initrd stands for initial ram disk. This is the first thing which loads once you power on your machine.
The below shown diagram explains the different stages. The firmware of the computer. Once the post is complete and the coast is clear the bios probes the mbr master boot.
Stage 1 boot loader mbr. Bootloader grub version 2 break down linux boot process steps 1. To be very brief this phase includes loading of the boot loader mbr and grub lilo into memory to bring up.
The bios stands for the basic input output system. Hardware power up cpu gets into real mode and jumps to fixed location 0xffff0 i e hardwired in the cpu circuit. Linux boot process 1.
Of course the power supply is the vital hardware part that powers your. Master boot record on linux. Now in linux there are six distinct stages to the boot process.
When you press the power button of the. The linux booting process 6 steps described in detail 1. Master boot record is the first place where boot loaders begins to start.