Understanding the Linux startup process

Boot Camp

Article from Issue 269/2023

If you want to troubleshoot startup issues, you need a clear understanding of how Linux boots.

This article explains the process through which the Linux kernel loads. In a more technical sense, it explains how the kernel gets into memory and what it actually does until the first user process begins its execution.

Boot Processes

At a very high level, the Linux boot processes pass through the five steps described below. Some texts can describe it in four or six steps; however, the basic mechanism remains the same. The boot process starts at the moment either when you start a shutdown system or restart an already running system.

Irrespective of the computer or OS standard ("IBM-compatible"), computer systems use either the classic BIOS/MBR [1] boot process or the modern UEFI/GPT boot process. UEFI firmware and conventional BIOS both manage system boot, but the boot method and settings differ for each.


Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • The State of Secure Boot

    Opinions differ on the UEFI boot security system, but one thing is certain: Secure Boot is here to stay. We thought it was time to ask, "How hard is it to boot a popular Linux distribution in a UEFI Secure Boot environment?"

  • UEFI and Secure Boot

    The coming Windows 8 implementation of UEFI with Secure Boot adds an extra layer of complexity for some Linux users. We look at the problem and two solutions from Fedora and Canonical.

  • UEFI Boot Fix

    A new universal workaround will keep Linux booting on the next generation of UEFI-enabled personal computers.

  • Linux Foundation Announces Secure Boot Solution

    Linux Foundation announces that Linux will continue to operate under Secure Boot-enabled systems.

  • Win8/Linux Dual-Boot

    Although getting Windows to play nice with an existing Linux installation is difficult, with a few tricks, you can set up Windows 8 to dual-boot with Linux.

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you've found an article to be beneficial.