ops 102 reading 03 - ElodieReb/reading-notes GitHub Wiki

Reading Notes for Class 03, Self-Paced Ops 102

Title = What is BIOS ?

Objective = This reading is relevant to what we are studying in class as we want to know the various points where problems might occur in a computer system's operation. Error in the BIOS or CMOS would be one of the first places something could go wrong when booting up a new computer system.

Reading Comprehension

  1. What is the BIOS? BIOS stands for Basic Input Output System. It is a system utility program that loads the operating system into the main system memory (RAM) when a computer is switched on. It also performs some initial diagnostic tests (POST) and initializes the hardware during the booting process.
  2. Use analogies from your previous background to explain what happens during the booting process? Starting first in technical terms, the booting process is initiated by the CPU, carried out by the BIOS, and ends when the OS is completely loaded into the main memory RAM and is fully operational. If I were to explain this to a mechanical engineer, I would explain how in a car, one needs to first turns the keys which triggers internal mechanisms to spark the pistons in the engine, and then the car will start. In this scenario, the turning of the keys is the action initiated by the CPU, the internal mechanism that sparks the pistons is the BIOS, and once the engine is running, that indicates the system is ready to receive further direction/inputs.
  3. What is the “Power On Self Test”? The Power On Self Test, aka POST, is a self-test that the BIOS carries out during booting. It is meant to check the computer system's internal hardware components for compatibility, connection, and error before loading the OS.
  4. What is the CMOS? The CMOS is the Complementary Metal Oxide Semiconductor. The CMOS provides the BIOS with information that is crucial to the booting process such as date, time, and other info about the user system settings preferences.
  5. What is the CMOS battery? The CMOS battery powers the CMOS RAM, allowing the CMOS to store date regarding the BIOS settings even after the computer is switched off.

Other Notes

  • The operating system acts as an interface between hardware components and the application programs in a computer system. That said, the user cannot operate the computer system until the OS is completely loaded into the main memory RAM and fully operational.
  • Everytime the computer system is switched on, the CPU's first job is to locate and initiate the process of loading the OS.
  • A firmware is software that is embedded into a ROM chip.

Things I'd Like to Know More About

  • The article states that the BIOS software is protected from any virus attack but that is not what the video we watched in lecture alluded to. Isn't it possible to "hack" the BIOS?
  • ^It is.