Extensible bios for boot support of devices on multiple hierarchical buses

In a computer system having a system BIOS, a CPU, a first bus, an add-in bus and extended bridge coupling said add-in bus and said first bus, an apparatus for extending boot support to devices connected to said add-in bus, said apparatus comprising:

• an extensible BIOS support coupled to said system BIOS;
• and
• a bridge extensible BIOS coupled to said extended bridge and carrying code for said system BIOS, said code including modules to be executed by said CPU, wherein said code carries specifications unique to said extended bridge enabling said system BIOS and said extensible BIOS support to identify and initialize devices coupled to said add-in bus, said devices not requiring modification to support said extensible BIOS support.

In a computer system having a system BIOS and a plurality of buses, at least one of said buses for connecting to at least one device, a method of extending boot-up capability to devices connected to said at least one bus comprising the steps of:

• initializing bridges that connect a first one of said buses with a second one of said buses;
• and
• initializing devices connected to said second one of said buses bus that are boot devices for boot-up of said computer system, said boot devices not requiring modification for carrying out said initializing of devices.