INT 13 command: SCSI Pass Through Proposal

Transcription

1 INT 13 command: SCSI Pass Through Proposal 8/25/2000 To: T13 Membership From: Ron Roberts, Adaptec Corp. Subject: EDD 3.0 comment Referencing the EDD specification, Rev 3.0 Feb 18, 2000 section 6.11, the Send Packet Command is defined. This command is adequate for implementing the SCSI pass through commands. This proposal describes a common method for issuing CDBs to a SCSI device. This allows a mechanism to issue any command to a SCSI device through the Adaptec SCSI BIOS. There are two possibilities when the SCSI BIOS is not available: 1. The user may choose to disable BIOS in SCSISelect. 2.The the BIOS will not be install if there is attached INT 13 device found.

2 INT 13 command: SCSI Pass Through Functional Specification (Rev 0.3) Sau Kuen Eng 7/5/2000 Adaptec Inc., 2000

3 Adaptec Revision History Date Revision Number Description 4/12/ Initial version. 6/13/ Added a variable for timeout. Changed sanity check to return number of SCSI channels in DX. Added function 2, SCSI channel information request. Added function 3, pass thru to SCSI channel/target/lun. 7/5/ Add a bit to indicate 32-bit linear addressing versa real mode segment offset

4 1.0 Introduction It is the intention of this document to describe a common method for issuing CDBs to a SCSI device. This allows a mechanism to issue any command to a SCSI device through the Adaptec SCSI BIOS. NOTE: There are two possibilities that the SCSI BIOS is not available: The first possibility is that user may choose to disable BIOS in SCSISelect. The next possibility is BIOS will not be install if there is attached INT 13 device found. 2.0 Reference documents BIOS Enhanced Disk Drive Service (EDD) Specification Rev 3, Feb 18, Overview Model Referencing the EDD specification, section 6.11, the Send Packet Command is defined. The command is adequate for implementing the SCSI pass through commands. 3.1 SCSI Pass Through Sanity Check The intent of the sanity check is to save time debugging and building the formatted packet data structure. A SCSI Pass Through Sanity Check is performed by a system or option ROM in the following manner. AL = 00h CX = 55AAh DL = Valid drive number supported by SCSI BIOS On return if NOT supported: Carry flag SET AH = 01 (Invalid command) CX=55AAh On return if supported: Carry flag CLEAR AH = 0 CX = AA55h SI = # of SCSI channels the BIOS supports BX = SCSI BIOS code segment

5 3.2 SCSI Pass Through INT 13 devices. AL = 01h DL = Drive number supported by SCSI BIOS (i.e. 80h, INT 13h controlled 1st drive,... ) ES:BX = Request packet buffer Table 1 Request packet Offset Length (bytes) Description 0 2 S=53h P=50h (5053h SCSI CDB signature) 2 1 CDB length (e.g. 6, 10 or 12) 3 1 Data Direction: bit 0 = 0 Read from device, bit 0 = 1 Write to device bit 7 = 0 Real mode seg:off addressing bit 7 = 1 32-bit linear addressing 4 4 Data transfer length 8 4 Data buffer - segment:offset 12 1 Host Adapter status 13 1 Target status 14 1 Sense data length 15 2 Timeout value (18 units per second) 17 1 Unused CDB 30 N Sense allocation area 3.3 SCSI Pass Through SCSI channels information AL = 02h DL = Valid drive number supported by SCSI BIOS ES:BX = SCSI channels information buffer Table 2 SCSI channels information Offset Length (bytes) Description 0 2 Buffer length (including buffer length) 2 2 PCI address (Bus:Device:Function) 4 2 Vendor ID 6 2 Device ID 8 2 Subsystem ID 10 8 Hardware name 18 2 # of SCSI targets attached 20 2 PCI address for next channel....

6 3.4 SCSI Pass Through SCSI targets AL = 03h CL bit 0-3 = Target # CL bit 6-4 = LUN # CL bit 7 = reserved CH = Channel # (zero based) DL = Valid drive number supported by SCSI BIOS ES:BX = Request packet buffer 3.5 BIOS Command Return Codes Any INT13h request, upon completion, return control to the requestor with a return code set in the carry flag and a status code placed in AH. CF= 0 Command completed with no error CF= 1 Error AH (hex) Definition Table 2 AH Status 00 No error 07 Parameter Failure 80 Timeout AA Device not ready BB Undefined Failure FF Sense operation failed The Target and Host Status tables are not required for the implementation of the SCSI Pass Through, however, vendor implementations that choose to implement a Target and/or Host Status shall follow the format outlined in Tables 3 and 4. Target Status (hex) Definition Table 3 Target Status 00 No error 02 Check condition 04 Condition met 08 Target busy 10 Intermediate command good 14 Intermediate condition met 18 Reservation conflict

7 Host status (hex) Definition Table 4 Host Status 00 No error 04 Command aborted by caller 05 Command aborted by HBA 11 Selection timeout 12 Data overrun/underrun error 13 Unexpected bus free 14 Target bus phase sequence error 1B Auto request sense failed 20 HBA hardware error 21 Target didn't respond to ATN(reset) 22 SCSI bus reset by HBA 23 SCSI bus reset by other device