A SYSTEM AND METHOD FOR PATCHING MICROCODE DURING THE DEBUGGING OF A PROCESSOR

摘要

The present invention discloses a system and method for patching revised microcode during debugging of a microprocessor to permit the revised microcode to be verified in a system environment prior to committing to silicon. The microprocessor includes an internal ROM in which microcode is embedded. If an error is detected in the microcode, a flag bit is set, and the microprocessor retrieves revised microcode from an external memory. The external memory may comprise an external ROM, on a card that plugs into an external peripheral bus. Alternatively, the external memory may comprise system memory. The microcode is loaded in system memory from a disk driver, such as an integrated hard drive, or a floppy disk drive. The microcode is stored in a reserved place in memory, and the BIOS is modified to preserve the security of the reserved portion of memory.