A.1 Designing a SCSI Class Driver

To the I/O Manager and any higher-level drivers layered above a SCSI class driver, most SCSI class drivers are standard kernel-mode intermediate drivers. Such a class driver must supply a set of Dispatch routines to which the I/O Manager and/or still higher-level drivers, such as FSDs, can send IRPs for appropriate I/O operations.

In addition, every class driver must have a DriverEntry routine and one or more IoCompletion routines. A SCSI class driver also can have any other standard higher-level driver routine, such as an Unload routine, as necessary.

For more information about standard kernel-mode driver routines, see Chapter 4 .