Motherboard BIOS - Shadow ROM


Staff member
Motherboard BIOS
The BIOS is a collection of programs embedded in one or more chips, depending on the design of your computer. That collection of programs is the first thing loaded when you start your computer, even before the operating system. Simply put, the BIOS in most PCs has four main functions:
- POST (power on self test). The POST tests your computer's processor, memory, chipset, video adapter, disk controllers, disk drives, Keyboard, and other crucial components.
- Setup System configuration and setup program. This is usually a menu-driven program activated by pressing and chipset setting along with the date and time, password, disk drives, and other basic system settings.
- Bootstrap loade. A routine that reads the disk drives looking for a valid master boot sector. This master boot sector program then continues the boot process by loading an operating system boot sector, which the loads the operating system core files.
- BIOS (basic input/output system. This refers to the collection of actual drivers used to act as a basis interface between the operating system and your hardware when the system is booted and running.

Shadow ROM
- ROM holds the BIOS, POST, and the program to boot the drives.
- ROM has a much longer access time than RAM, slowwing down the system.
- If, on boot up, the ROM is copied into RAM, the system now can access this fast RAM that is shadowing the slow ROM, considerable speeding up the overall system operation
+ System BIOS shadowed
+ Video BIOS shadowed