PDDREF:Using Advanced Bios (ABIOS)

Physical device drivers that invoke Advanced BIOS (ABIOS) are commonly known as physical ABIOS device drivers. These device drivers use one of the following transfer conventions:

• ABIOS Transfer Convention
• Operating System Transfer Convention.

For the ABIOS Transfer Convention, the ABIOS common entry points are invoked to locate the specific start, interrupt, or timeout entry points for the requesting Logical ID.

For the Operating System Transfer Convention, the specific start, interrupt, or timeout entry points must be located and called for the requesting Logical ID. OS/2 internal device drivers use the Operating System Transfer Convention to invoke ABIOS services. User-written, installable device drivers can use either the ABIOS Transfer Convention or the Operating System Transfer Convention. Device Helper services (DevHlps) are provided for both calling conventions.

For performance reasons, ABIOS device drivers should call ABIOS services with processor interrupts enabled.