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Emerson MVME147 manual Writing A Driver

Models: MVME147

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WRITING A DRIVER

xx08: SIMILAR TO xx08 ABOVE, ONLY THE DATA RECEIVED HAS SOME PARITY ERROR

OCCURRED.

2.FINAL RETURNS:

STATUS WORD BIT 13:	IF CLEAR, SOMEHOW RESTORE
	REGISTER
(RTE)	SET AND PERFORM AN RTE. IF SET,

THE FIRST RETURN FROM THE SCSI

FIRM-

WARE (COMMAND THREAD) AND THE

USER

SHOULD RETURN TO WHOMEVER

CALLED

THE DRIVER (RTS, ETC.).

SAMPLE RETURN CODE FOR ONE OF MANY CALLERS OF THE SCSI FIRMWARE:

Note

It may not be clear to the casual reader that address register A3 is not modified in this return code. If an RTE is to be executed, address register A3 points to the register save area. The subroutine RESTORE_REG uses register A3 to restore the registers D0 through D7 and A0 through A6. If a reentry to the RTE entry is executed, the address register A3 must remain intact.

(SCSI_RET: is the label that is pointed to by the vector provided in the user packet.)

SCSI_RET:

5-10

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Contents

Features GENERAL INFORMATIONIntroduction Modes of OperationMVME147 SCSI Firmware Entry Points The SCSI firmware initializes these vectors Equipment Supported CONTROLLE CONTROLLE CONTROLLEDEVICE PARTDevices Supported Under Common Command Set CONTROLLEDEVICE PARTRelated Documentation MOTOROLADOCUMENT TITLE PUBLICATION NUMBERManual Terminology MOTOROLAGENERAL INFORMATION Initiator Role Custom Packet CUSTOM SCSI PACKETSIntroduction CUSTOM SCSI PACKETS Initiator Role Custom Packet NOTES PHASE CODE PHASEInitiator Role Custom Packet +$00 +$68 status Note ASYNC the firmware status xxxxxxxx xxxxxxxx Page CUSTOM SCSI PACKETS Initiator Role Custom Packet CUSTOM SCSI PACKETS TARGET Enable Custom Packet TARGET Enable Custom PacketNOTES Status from SCSITARGET Enable Custom Packet TARGET Sequence Custom Packet TARGET Sequence Custom Packet CUSTOM SCSI PACKETS NOTESTARGET Sequence Custom Packet WORDS $04 and $06 CUSTOM SCSI PACKETS TARGET Sequence Custom Packet CUSTOM SCSI PACKETS TARGET Sequence Custom Packet RETRY COUNT. Not used by the TARGET role firmwareCUSTOM SCSI PACKETS Packet Return Status PACKET RETURN STATUSControl Flags SCSI Bit 3 FM Filemark Bit 4 COMMAND RETRY 1 = Retries were performed Bit 5 COMMAND REThe command was retried retry count times Packet Return Status Bit 2 EOM End of mediaPACKET RETURN STATUS Table 3-1.Packet Status Codes Intermediate ReturnCodes CODEFinal Return Codes Table 3-1.Packet Status CodesCODE Intermediate ReturnTable 3-2.Packet Status Codes cont’d SCSI Bus Reset Packet section in ChapterCODE MEANINGRequest-Sense-Data Error-Class7 Codes Table 3-3.Packet Status Codes cont’dController-Dependent CODESCSI Status Returned in Status Phase Table 3-4.Packet Status Codes cont’dCODE MEANINGRequest-Sense-Data Error-Class0 through 6 Codes Table 3-5.Packet Status Codes cont’dCODE Controller-DependentPage PACKET RETURN STATUS SCSI FIRMWARE INTERRUPT STRUCTURE SCSI Firmware Interrupt StructureSCSI FIRMWARE INTERRUPT STRUCTURE WRITING A DRIVER SCSI_CMDSCSI_ACTV SCSI_INTPassing Commands to the SCSI Firmware Building the PacketInterface Rules for the SCSI Firmware Figure 5-1.SCSI Disk Driver Interface to VERSAdosInterface Rules for Multiple Callers WRITING A DRIVER Care must be taken not to modify the contents of WRITING A DRIVER Interface Rules for the SCSI Firmware FUNNEL WRITING A DRIVER Interface Rules for the SCSI Firmware WRITING A DRIVER MOVE.W 2A2,D0 THE CODE BELOW HANDLES FINAL RETURN CODES Interface Rules for a Single Caller WRITING A DRIVER MVME147 SCSI Firmware Background TARGET ROLE ROUTINESIntroduction SCSI Versus SASI Rules Custom Sequence PacketCommand Table ScriptEnabling TARGET Role Enabling TARGET Role Servicing the TARGET Requests Servicing the TARGET Requests TARGET ROLE ROUTINES Servicing the TARGET Requests TARGET ROLE ROUTINES Servicing the TARGET Requests TARGET ROLE ROUTINES SCSI PACKETS Table 7-1.SCSI FunctionsIntroduction SCSIRead/Write Packet TableSCSI Functions cont’d SCSIDISK and TAPE Controller logical unit in SG table, if zero SCSI PACKETS Old Packet Supported for Compatibility+$12 in SG table, if zero DMA Scatter/Gather Table Entry Read/Write Packet|function code 3 bits 1 = link to next entryFor example $5 isCOMMAND Attach/Detach Packet all devicesCOMMAND CONTROLLERCOMMAND Attach/Detach Packet all devicesSCSI PACKETS +$1E FM encoding, single Controller type refer xxxxxxxx attributes byte offset +$20 Single track density Drive type 0 = Attach/Detach Packet all devices Example for floppy3½, 5¼ 3½, 5¼,3½, 5¼ 3½, 5¼,3½, 5¼ 3½, 5¼+$04 Minimum read QIC-24 if this is set to 0, the +$00 Reserved Interrupt level +$00 +$9E $00 Format Packet Assign Alternate Sector Packet SCSI COMMAND+$0E Assign Alternate Sector Packet SCSI SCSI PACKETS DEFECT LIST TYPE0 Note 3, NOTES Head Bytes from Index MSW NoteSCSI Bus Reset Packet Controller logical unit SCSI Controller Reset Packet Erase Packet+$12 Rewind Packet Device logical unit Read Block Limits Packet SCSI PACKETS where n = number of blocks or filemarks to Space Status from SCSI Write Filemarks Packet Write Filemarks PacketThe table below shows the write filemarks packet Controller logical unit The controller must be in general or read mode Verify CRC PacketTape Mode Select/Sense Packet Tape Mode Select/Sense Packet Number of tracks on Inquiry Packet +$00 Reserved +$1A Load/Unload Packet +$14 Recover Buffer Data Packet +$0C Request Sense Data Packet Controller logical unit Check Status Packet Open Packet SCSI PACKETSOpen Packet SCSI PACKETS BYTE OFFSET COMMON COMMAND SET AND DISK OPERATIONBYTE BYTE OFFSET BYTEBYTE OFFSET ENTRY NUMBER BYTE OFFSETCOMMON COMMAND SET AND DISK OPERATION NOTESSend mode select command COMMON COMMAND SET AND DISK OPERATION DEFECT LIST DEFECT LIST TYPEBYTE OFFSET NOTESBYTE OFFSET Mode Select HeaderBYTE OFFSET Block Descriptor BYTE OFFSETNOTES COMMON COMMAND SET AND DISK OPERATIONBYTE OFFSET Mode Select Header BYTE OFFSETBlock Descriptor BYTE OFFSETBYTE OFFSET BYTE OFFSETNOTES VALUEMode Select Command CDB BYTE OFFSETVALUE COMMENTSCOMMON COMMAND SET AND DISK OPERATION Mode Select HeaderBYTE OFFSET Block DescriptorBYTE OFFSET BYTE OFFSETPage code NOTES COMMON COMMAND SET AND DISK OPERATIONBYTE OFFSET ATTRIBUTE FLAGS MEDIATYPE Mode Select HeaderCOMMON COMMAND SET AND DISK OPERATION ATTRIBUTE FLAGSMEDIA TYPEBYTE OFFSET BYTE OFFSETNOTES VALUEPIN 34 CONTROL COMMON COMMAND SET AND DISK OPERATIONPin 2 and Pin 34 Definition for High Density Pin 2 and Pin 34 Definition for Low DensityPIN 34 CONTROL PIN 2 CONTROLCOMMENTS Pin 34 = driveA-22