An x86 based computer system that implements an advanced firmware based boot process without a conventional x86 BIOS. The computer system includes an x86 processor coupled to a volatile memory and a non-volatile memory via a bus, wherein the non-volatile memory includes an advanced firmware. The advanced firmware is executed by the processor to implement a boot sequence. During the boot sequence, the computer system initializes device drivers using the advanced firmware and interfaces with advanced firmware compliant program with the device drivers of the computer system. The computer system also initializes a virtual compatibility machine for supporting legacy software programs. The virtual compatibility machine includes a plurality of compatibility models. The compatibility models function by interfacing with legacy software programs and by translating functions received from the legacy software programs via the compatibility models into corresponding functions performed by the device drivers of the computer system, thus allowing the computer system to run both legacy software programs and advanced firmware compliant software programs natively.