User talk:Klae0010

Chapter 8 – System initialization and X-Windows

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Subjects covered:

Boot Process

• Power on
• System initializes
• BIOS performs POST (power-on self test)
• BIOS checks configuration and checks for boot devices and an OS to execute
  • Typically floppy disks, CDs, DVDs, and USB devices are checked as they can contain installation media for an OS.
  • If an OS isn’t found, the BIOS will check the MBR/GPT on the first HD.
  • MBR/GPT may point to the partition where the boot loader found. If this is the case then the partition where the boot loader is found is called the active partition.

See page 347 of the book for the flowchart of the boot process

Boot loader – main purpose is to load the OS kernel into memory.

NOTE: There can only be one active partition per HD.

• Regardless of whether the boot loader is loaded from the MBR/GPT or the active partition the rest of the boot process continues as normal. Which is.. The kernel is executed and loaded into memory.
• After loading the kernel, the boot loader becomes inactive.
• Kernel continues by loading daemons into memory
• Daemons are a system process which performs tasks such as printing scheduling, and OS maintenance.
  • The first daemon process is called the initialize (init) daemon. It’s responsible for loading all the other daemons on the system required to bring the system to a usable state where users can interact with it.

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