Bus Driver Interface APIs

This layer of interfaces is implemented by the lowest level layer of drivers, using DKI services. This set of drivers can itself be composed of multiple sub-layers to reflect the bus hierarchy of a given platform.

Typically, only the primary (host) bus driver is built solely using DKI services. Subsequent drivers, those occupying a "downstream" position in the hierarchy, interface with the primary (host) bus. As all different I/O buses share a subset of features, and then have their particular specificities, the bus driver interfaces layer offers a subset of services called "Common bus driver interface" (CBDI) , which is independent of the bus type, offering a set of services common for all bus classes.

In addition to the CBDI, there is of course a collection of bus specific interfaces (such as PCI, VME, ISA) to implement bus-specific driver services.