Device drivers for multitasking operating system.

摘要

A tiered device driver system includes a SCSI generic device driver (SGDD) in one tier and one or more SCSI device-class drivers (SDCD) in another tier. In response to a request to access a SCSI device, the operating system creates a request packet that is passed to the appropriate SDCD. Such SDCD creates a generic request packet and associated data structures that contain information specific to the SCSI device being accessed. The generic request packet is passed on to a SCSI generic device driver (SGDD) that creates a SCSI ABIOS request block which it transmits to a SCSI adapter for accessing the desired SCSI device. The SGDD provides functions common to the SDCDs. <IMAGE>