Arch Linux Boot Process - ryzendew/Linux-Tips-and-Tricks GitHub Wiki

Arch Linux Boot Process Guide

Complete beginner-friendly guide to the boot process on Arch Linux, including boot stages, init systems, and boot troubleshooting.

Table of Contents

  1. Boot Stages
  2. BIOS/UEFI Boot
  3. Bootloader
  4. Kernel Loading
  5. Init System
  6. Troubleshooting

Boot Stages

Boot Sequence

Boot stages:

  1. BIOS/UEFI: Hardware initialization
  2. Bootloader: Loads kernel
  3. Kernel: Starts system
  4. Initramfs: Initial filesystem
  5. Init System: Starts services
  6. Login: User login

BIOS/UEFI Boot

BIOS Boot

BIOS process:

  1. Power on
  2. POST (Power-On Self-Test)
  3. Find boot device
  4. Load bootloader

UEFI Boot

UEFI process:

  1. Power on
  2. UEFI initialization
  3. Find EFI partition
  4. Load bootloader

Bootloader

GRUB Boot

GRUB process:

  1. Load GRUB
  2. Show menu
  3. Load kernel
  4. Pass control to kernel

systemd-boot

systemd-boot process:

  1. Load systemd-boot
  2. Show menu
  3. Load kernel
  4. Start systemd

Kernel Loading

Kernel Boot

Kernel process:

  1. Load kernel
  2. Load initramfs
  3. Initialize hardware
  4. Mount root filesystem
  5. Start init

Initramfs

Initramfs purpose:

  • Load modules
  • Mount root
  • Unlock encryption
  • Start init

Init System

systemd

systemd process:

  1. Start systemd
  2. Load units
  3. Start services
  4. Show login

Check Boot

Analyze boot:

# Boot time
systemd-analyze

# Detailed
systemd-analyze blame

# Critical chain
systemd-analyze critical-chain

Troubleshooting

Boot Hangs

Check logs:

# Boot from USB
# Chroot into system
# Check logs
journalctl -b -1

Kernel Panic

Fix kernel:

# Boot from USB
# Chroot
# Reinstall kernel
pacman -S linux linux-headers
mkinitcpio -P

Summary

This guide covered boot stages, BIOS/UEFI, bootloader, kernel, init system, and troubleshooting.

Next Steps

This guide is based on the ArchWiki. For the most up-to-date information, always refer to the official ArchWiki.