1 / 14

CS101 Lecture 9

CS101 Lecture 9. Booting A Computer. Booting Up A Computer Dilemma. To get our computer running we need the OS To survive when the computer is turned off the OS must be saved to a storage device, usually the hard drive

auryon
Download Presentation

CS101 Lecture 9

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CS101 Lecture 9 Booting A Computer

  2. Booting Up A Computer Dilemma • To get our computer running we need the OS • To survive when the computer is turned off the OS must be saved to a storage device, usually the hard drive • The OS knows how to get software off of the hard drive so it can run on the computer, but the OS is in the hard drive when the computer tries to start so it cannot get itself out of the hard drive • How does the computer start up without the OS?

  3. The Computer Uses Its Firmware • Two types of firmware: • BIOS (Basic Input Output System) • Older method that has been in use since the 1970’s. • Older Windows computers still use BIOS • UEFI (Unified Extensible Firmware Interface) • Newer way invented by Intel in mid - 1990’s • Used by Macs and newer Windows computers • Will take over during this decade

  4. Booting a computer • When you press the Power button an electrical signal is sent to the Erasable Programmable Read Only Memory or (EPROM) • EPROM has the special ability to be able to store zeros and ones without any power being supplied • The EPROM is where the computer’s firmware stored (either BIOS or UEFI) • The firmware instructions are used to get the computer started

  5. iClicker • Have you ever updated your firmware? • Yes • No

  6. iClicker • Can you permanently ruin your computer by updating the firmware? • Yes • No

  7. Firmware’s Duties • The principal duties of the firmware during booting are as follows: • Verify the integrity of the firmware code itself • Run the Power On Self Test (POST) • discover, initialize, and catalog all system buses and devices • Stop boot up if fails test • Check to see if it needs to provide a user interface for system's configuration • Identify, organize, and select which devices are available for booting • Construct whatever system environment that is required by the target OS and load the OS from the storage device.

  8. Firmware loads OS from drive • Last thing firmware does is look on the storage devices for the OS • Firmware instructs disk where OS is found to send an electrical copy of the OS to RAM and then tells the processor to start processing the OS directions that are in RAM • More and more files are copied from the disk into RAM until the OS is loaded and controlling the computer • Once the OS is loaded into memory and running it takes over charge of the computer

  9. iClicker • Which is the correct order? A) Power > Firmware Activated > POST > OS loaded from storage device B) Power > POST > Firmware Activated > OS loaded from storage device C) POST > OS loaded from storage device > Firmware Activated > Power D) I press the power button and just go get coffee

  10. How to bring up firmware user interface. • Enter Windows = Look for key to hold down during startup. • Enter Mac = Can’t. • Hold T key for Target Disk Mode • Hole Option key to choose start up disk • Install rEFIt

  11. Why do we care how a computer starts?

  12. #1 Fix a Non-Booting Computer • Interpret POST beep codes • Enter the Firmware to fix computer • Change boot order • Tell computer to boot from optical drive. • Boot computer off emergency CD and run repair utilities

  13. #2 Change Firmware Options • Turn on firmware security • Cannot boot computer without password • Change energy setting • Can save money on utility bill • Etc.

  14. iClicker • Are you now considering turning on firmware security? • Yes • No

More Related