System for updating computer's existing video BIOS without updating the whole computer's system BIOS

摘要

A computer system's existing video BIOS is updated independently without the need for updating the computer system's entire system BIOS, by transferring a new video BIOS contained on a floppy disk into a flash memory block dedicated for video-BIOS storage. The video-BIOS update mode is entered by initializing the computer and pressing a “hot key sequence” while the computer is being initialized. Once the hot key sequence has been detected, the system BIOS reads the new video BIOS from the floppy disk and performs a security check to ensure that the new video BIOS contained on the floppy disk is known to the system BIOS. The security check involves decoding the digital signature of the new video BIOS with a corresponding public key stored with the system BIOS. Once the security check has been completed, the system BIOS writes the new video BIOS into a dedicated 64K flash-memory block. In addition to facilitating updates of the video BIOS independent of the system BIOS, “chipset patches” may be loaded onto a chipset along with the new video BIOS. A “chipset patch” is a code segment that may be loaded onto the chipset to fix problems on the chipset. The chipset patches are utilized to fix detected problems on the chipset by means of setting register bits within the chipset to proper values.