BIOS

Tags

comp-arch

Is firmware (embedded as a special chip in a computers motherboard) which contains instructions for booting it up. The boot chip tells the computer to look in a fixed place, usually the lowest numbered hard disk (the boot disk), for the boot loader which is loaded into memory and started.

The BIOS is often given the very simple job of simply starting the bootloader because its not very advanced. It was originally written for primitive 8-bit PCs with tiny disks and therefore can't access enough of the disk to load the kernel directly.