Open SCSI Integrator's Manual for NonStop S-Series Servers

The Open SCSI I/O Process (IOP)

Open SCSI Integrator’s Manual for NonStop Servers—422988-002

4-9

The CAM Control Block (CCB)

When you use the Open SCSI interface, the CCB control field in the WRITEREAD

buffer must correspond exactly to the structure of a CCB for each CAM operation, even

if not all the fields of the CCB are needed by a particular operation. One exception to

this is that the Open SCSI IOP does not support the Connect ID field of the CCB (see

Table 4-3

on page 4-12), because this path information is specified when the IOP is

configured through SYSGENR.

CAM Operations

Table 4-1 shows the Common Access Method (CAM) operations, shows which ones are

supported by the Open SCSI IOP, and also directs you to a table describing the CCBs

structure for each supported operation. These operations are described in detail in the

ANSI CAM specification Information Technology - SCSI-2 Common Access Method

Transport and SCSI Interface Module (ANSI X3.221 - 1994).

Table 4-1. CAM Operations (page 1 of 2)

CAM Operation

Code

(in hex) Description

Supported by

Open SCSI?

00 No Operation (see Table 4-3 on page 4-12) Yes

01 Execute SCSI I/O (see Table 4-5 on page 4-13) Yes

02 Get Device Type No

03 Path Inquiry No

04 Release SIM Queue (see Table 4-3 on page 4-12) Yes

05 Set Async Callback No

06 Set Device Type No

07 Scan SCSI Bus No

08-0F (Reserved) -

10 Abort SCSI Command (see Table 4-4 on

page 4-13)

Yes

11 Reset SCSI Bus No

12 Reset SCSI Device (see Table 4-3 on page 4-12) Yes*

13 Terminate I/O Process No

14-1F (Reserved) -

20 Engine Inquiry No

21 Execute Engine Request No

22-2F (Reserved) -

30-3F Target mode and reserved operations No

40-7F (Reserved) -