📖 IT Bible

The Boot Process

  1. Computer powers on
  2. BIOS/UEFI & POST
    • The BIOS is a low-level software that initializes a computer’s hardware to make sure everything is good to go
    • To set the boot order for a computer, you need to enter the BIOS and configure the boot options.
    • The Boot Options menu is where you can set your preferred boot method.
    • The boot options menu lists all the devices attached to your system where it may find a bootloader program
  3. Boot Device
    • hard drives
    • USB drives
    • CD drives
  4. Bootloader - small program that loads the OS
  5. Loads OS
  6. Loads Kernel
  7. Launch System Processes and User Space
    • user login
    • spinning up desktop environment

Disk partitions: You can create partitions on your computer’s drive so that only one part of the drive runs the boot process. A common reason to partition your drive is to have two separate operating systems on your computer. For example, you could have Windows on one partition of your drive and Linux on the other. When you have two operating systems on your drive, you must choose which one will run the boot process. Having two possible systems to boot into is called dual booting.

Key Takeaways

There are multiple ways to boot a computer.

  • A computer can be partitioned into different operating systems and you can select which OS to use when booting.
  • You can boot from an external tool. External tools include USB drives, optical media, solid state boot drives, external hot-swappable drives, network booting, and internet-based booting.
  • Choosing a boot method on startup varies depending on which operating system you use.