┌───────────────┬───────────────┬───────────────┬───────────────┐ │Offset │# Bytes │Description │R/W* │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │00h (00) │01h (01) │Command Code = │W │ │ │ │1 │ │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │01h (01) │01h (01) │Status │R │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │02h (02) │01h (01) │Host Adapter │W │ │ │ │Number │ │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │03h (03) │01h (01) │SCSI Request │W │ │ │ │Flags │ │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │04h (04) │04h (04) │Reserved for │- │ │ │ │Expansion = 0 │ │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │08h (08) │01h (01) │Target ID │W │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │09h (09) │01h (01) │LUN │W │ ├───────────────┼───────────────┼───────────────┼───────────────┤ │0Ah (10) │01h (01) │Peripheral │R │ │ │ │Device Type of │ │ │ │ │Target/LUN │ │ └───────────────┴───────────────┴───────────────┴───────────────┘*The R/W column indicates whether the field is sent to ASPI (W), returned from ASPI (R), or reserved (-).
This command always returns with a non-zero status.
A SCSI Request Completed Without Error (01h) status indicates that the specified device is installed and the peripheral device type field is valid. A SCSI Device Not Installed Error (82h) indicates that the peripheral device type field is not valid.
This command is intended for use by various drivers, during initialization, for identifying the targets that they need to support. A CD-ROM driver, for example, can scan each Target/LUN on each installed host adapter looking for the device type corresponding to CD-ROM devices. This eliminates the need for each driver to duplicate the effort of scanning the SCSI bus for devices.
The peripheral device type is determined by sending a SCSI Inquiry command to the given target. Refer to any SCSI specification to learn more about the Inquiry command. The SCSI Request Flags field is currently undefined for this command and should be zeroed.