Transparently self-configured option board using an option board protocol PROM

摘要

The present invention is an option board protocol (OBP) PROM for interfacing an optional peripheral device or board with a host computer system without retrofitting the CPU PROM. In general, the CPU PROM does not recognize option boards unless they are known to the designer of the CPU PROM and properly controlled by built-in drivers of the CPU PROM as accessed through a ROMVEC Table of the CPU PROM. The OBP PROM allows the option board to participate in the Power On sequence just as other standard peripheral devices. During a POST sequence, the CPU activates the OBP code, installs the diagnostics, and then the OBP PROM tests the option board itself, using tools provided by the CPU PROM. The OBP PROM may load its own driver before completing the POST sequence. The OBP support code in the CPU PROM provides three new functions to reduce the duplication of code, to standardize the testing methods and to streamline the diagnostic functions of the POST sequence.