
BIOS ( Basic Input Output System ) is an essential set of programs stored on a chip on the motherboard of a computer
It acts an intermediary between computer hardware and its operating system without it , the PCs operating system cannot communicate with or take control of the hardware.
Difference between BIOS and UEFI
BIOS:
1.Windows blue screen
2.No animation
3.Can’t recognize Ethernet, WI-FI and Bluetooth
4.No remote diagnosis and repair support
5.No mouse support, keyboard only
6.No secure booting option
7.Firmware program in 16-bit assembly language
8.Supports 2.2 terabytes
UEFI:
1.User friendly graphical user interface
2.Multi colored with animations
3.Support Ethernet, WI-FI and Bluetooth connectivity
4.Support remote diagnosis and repair if the OS won’t boot
5.Keyboard and mouse support
6.Secure boot facility to stops loading malicious software
7.Firmware program in 64-bit c language
8.Supports drive sizes up to 9 zettabytes
Let see how works
4 main function of BIOS
- Power on self-test (POST)
- Bootstrap loader
- Setup utility program
- BIOS drivers
Functions of BIOS
Power on self-test:
Conducts power on self-test (post) a built- in diagnostic program that checks whether the computer has all of the necessary parts and functioning properly, such as memory and keyboard.
Bootstrap loader:
helps in loading the operating system
The program searches for any available operating system and if found, it loads the operating system into RAM of the computer.
Setup utility program:
A non-volatile memory (NVRAM) is used to store information about the computer system. During installation of a system, the user runs BIOS setup program and enters the correct parameters the setting of memory, disk types and other setting are stored in NVRAM.
BIOS driver:
It is collection of programs stored in one or more EPROM (Erasable programmable read-only me memory) or EEPROM (electrically Erasable programmable read only memory) chips, depending on the computer design, on the motherboard.