.TITLE	XXDRV
	.IDENT	/00/
 
;+
; XXDRV.SMC
;
;
;
; 	** SKELETON RSX-11M I/O DRIVER **
;	**	SUPERMAC VERSION       **
;
; INSTRUCTIONS FOR USE:
;
;	THIS IS A SKELETON I/O DRIVER FOR RSX-11M. IT
;	CONTAINS ALL THE NECESSARY BOILERPLATE THAT IS
;	REQUIRED TO BE IN EVERY RSX-11M I/O DRIVER.
;
; 	THE USER MUST INSERT ALL THE DEVICE-SPECIFIC 
;	PROCESSING FOR THE INTENDED DEVICE. REFER TO
;	THE "GUIDE TO WRITING AN I/O DRIVER" MANUAL
;	FOR INTIMATE DETAILS.
;
;	OTHER FILES FOR SKELETON DEVICE DRIVER:
;		
;		XXDF.MAC	SYMBOL DEFINITIONS, MACROS
;		XXTAB.MAC	SKELETON DATA BASE
;		XXMAKE.CMD	COMMAND FILE FOR ASSEMBLING/TASK-BUILDING
;
;
;
;
;	REMEMBER TO CHANGE ALL REFERENCES TO X$$X11 TO THE
;	PARTICULAR LABEL USED TO DEFINE THE
;	NUMBER OF DEVICE CONTROLLERS FOR THE ACTUAL DEVICE
;	YOU'RE CONFIGURING INTO THE SYSTEM.
;
;
;	;;; COMMENTS INDICATE CODE EXECUTED WITH 
;	    PROCESSOR INTERRUPTS DISABLED.
;
;
;
;	*** REQURES SUPERMAC VERSION 46 OR LATER ***
;
;
;
; SEE ALSO OTHER INSTRUCTIONS IN XXTAB.MAC 
;
; COMMAND LINE FOR ASSEMBLY:
; PIP>XXDRV.SRC/NV=LB:[11,10]RSXMC,SY:[<UIC>]XXDF,XXDRV
; MAC>XXDRV,XXDRV=LB:[1,1]EXEMC/ML,SUPERMAC/ML,SY:[<UIC>]XXDRV.SRC
; PIP>XXDRV.SRC;*/DE
;
;
; J. MCGLINCHEY		VERSION 00	15-APR-80
;-
	.PAGE
;
; MACRO LIBRARY CALLS (DELETE THE ONES NOT USED)
;

	.MCALL	ABODF$,HWDDF$,PKTDF$
	.MCALL	SCBDF$,UCBDF$,DCBDF$
	ABODF$			;DEFINE TASK ABORT CODES
	HWDDF$			;DEFINE HARDWARE REGISTERS
	PKTDF$			;DEFINE I/O PACKET OFFSETS
	SCBDF$			;DEFINE SCB OFFSETS
	UCBDF$			;DEFINE UCB OFFSETS
	DCBDF$			;DEFINE DCB OFFSETS

	.MCALL	SMACIT		;INVOKE SUPERMAC
	SMACIT
 
	.PAGE
	.SBTTL	LOCAL DATA, DISPATCH TABLE

;
; LOCAL DATA
;
; CONTROLLER IMPURE DATA TABLES (INDEXED BY CONTROLLER NUMBER)
;

CNTBL:	.BLKW	X$$X11		;ADDRESS OF UNIT CONTROL BLOCK


	.IF GT	X$$X11-1

TEMP:	.BLKW	1		;TEMPORARY STORAGE FOR CONTROLLER NUMBER

	.ENDC


;
; DRIVER DISPATCH TABLE
;

$XXTBL::.WORD	XXINI		;DEVICE INITIATOR ENTRY POINT
	.WORD	XXCAN		;CANCEL I/O OPERATION ENTRY POINT
	.WORD	XXOUT		;DEVICE TIMEOUT ENTRY POINT
	.WORD	XXPWF		;POWERFAIL ENTRY POINT

	.PAGE
	.SBTTL	INTERRUPT SERVICE
 
;   $XXINT  CONTROLLER INTERRUPT SERVICE ROUTINE

PROCEDURE $XXINT,GLOBAL
  BEGIN INTERRUPT
    DEBUG  1					;;; DEBUGGING BREAKPOINT
    INTSV$ XX,XXPRI,X$$X11			;;; GENERATE INTERRUPT SAVE CODE
    DEBUG 1					;;; DEBUGGING BREAKPOINT
    PUSH R0,R1,R2,R3				;;; SAVE REGS (R4, R5 ALREADY SAVED)
    LET R4 := U.SCB(R5)				;;; GET ADDRESS OF STATUS CONTROL BLOCK
    LET @S.CSR(R4) := @S.CSR(R4) OFF.BY #IE	;;; DISABLE DEVICE INTERRUPTS
 
;	.
;	.	*** DEVICE-SPECIFIC INTERRUPT SERVICE CODE ***
;	.
 
    POP  R3,R2,R1,R0				;;; RESTORE REGISTERS
  END INTERRUPT					;;;
 
  $CALL $FORK					;;; CREATE A SYSTEM PROCESS
 
  BEGIN FORKPROCESS				;
    IF #ERR SET.IN @S.CSR(R4)			; WAS THERE AN ERROR?
    DEBUG 1					; DEBUGGING BREAKPOINT
;				
;		 DEVICE SPECIFIC FORK LEVEL CODE
;		 GOES HERE
;
;		 POSSIBLE THINGS TO DO:
;		   DECODE ERRORS
;		   CALCULATE RETURN BYTE COUNT
;		   LOG ERRORS
;		   RETRY OPERATION
    ELSE
      LET R1 := S.PKT(R4)			; FIND THE I/O PACKET
      LET R1 := I.PRM+4(R1)			; SET RETURN BYTE COUNT
      LET R0 := #IS.SUC				; SET RETURN STATUS
      LET R2 := #0				; SET RETRY COUNT
      PUSH R4
      $CALL $IODON				; AND TERMINATE I/O OPERATION
      POP R4
    END <IF>
    LET @S.CSR(R4) := @S.CSR(R4) SET.BY #IE	; ENABLE DEVICE INTERRUPTS
  END FORKPROCESS
 
 
 
 
;	*** NOTE: FALLS THROUGH INTO INITIALIZATION CODE ***
	.PAGE
	.SBTTL	CONTROLLER INITIATOR
;+
;     XXINI  CONTROLLER INITIATOR
;
; THIS ROUTINE IS ENTERED FROM THE QUEUE I/O DIRECTIVE WHEN AN I/O REQUEST
; IS QUEUED AND AT THE END OF A PREVIOUS I/O OPERATION TO PROPAGATE THE EXECU-
; TION OF THE DRIVER. 
;
;	IF (SPECIFIED CONTROLLER IS NOT BUSY)
;	   THEN (TRY TO DEQUEUE NEXT I/O REQUEST)
;	      IF (DEQUEUE SUCCESSFUL)
;		THEN (INITIATE NEXT I/O OPERATION)
;	   RETURN TO CALLER.
;
; INPUTS:
;
;	R5=ADDRESS OF THE UCB OF THE CONTROLLER TO BE INITIATED.
;
; OUTPUTS:
;
;	IF (SPECIFIED CONTROLLER NOT BUSY)
;	   THEN IF (I/O REQUEST WAITING)
;	      THEN (DEQUEUE REQUEST;
;		    INITIATE I/O OPERATION)
; 
; THE FOLLOWING ARGUMENTS ARE RETURNED BY $GTPKT:
;
;	R1=ADDRESS OF THE I/O REQUEST PACKET.
;	R2=PHYSICAL UNIT NUMBER OF THE REQUEST UCB.
;	R3=CONTROLLER INDEX.
;	R4=ADDRESS OF THE STATUS CONTROL BLOCK.
;	R5=ADDRESS OF THE UCB OF THE CONTROLLER TO BE INITIATED.
;
;  I/O REQUEST PACKET FORMAT:
;
; I.LNK		WD. 00 -- I/O QUEUE THREAD WORD.
; I.PRI,I.EFN	WD. 01 -- REQUEST PRIORITY, EVENT FLAG NUMBER.
; I.TCB		WD. 02 -- ADDRESS OF THE TCB OF THE REQUESTER TASK.
; I.LN2		WD. 03 -- POINTER TO SECOND LUN WORD IN REQUESTER TASK HEADER.
; I.UCB		WD. 04 -- CONTENTS OF THE FIRST LUN WORD IN REQUESTER TASK HEADER (UCB).
; I.FCN		WD. 05 -- I/O FUNCTION CODE 
; I.IOSB	WD. 06 -- VIRTUAL ADDRESS OF I/O STATUS BLOCK.
;		WD. 07 -- RELOCATION BIAS OF I/O STATUS BLOCK.
;		WD. 10 -- I/O STATUS BLOCK ADDRESS (REAL OR DISPLACEMENT + 140000).
; I.AST		WD. 11 -- VIRTUAL ADDRESS OF AST SERVICE ROUTINE.
; I.PRM		WD. 12 -- RELOCATION BIAS OF I/O BUFFER.
;		WD. 13 -- BUFFER ADDRESS OF I/O TRANSFER.
;		WD. 14 -- NUMBER OF BYTES TO BE TRANSFERRED.
;		WD. 15 -- NOT USED.
;		WD. 16 -- NOT USED.
;		WD. 17 -- NOT USED.
;		WD. 20 -- NOT USED.
;-
	.PAGE

;
; AT THIS POINT:
;	IF UC.QUE=1
;	   R5 - UCB ADDRESS
;	   R4 - SCB ADDRESS
;	   R1 - ADDR OF I/O PACKET
;	IF UC.QUE=0
;	   R5 - UCB ADDRESS
;
PROCEDURE XXINI,GLOBAL
  BEGIN INITIATE
    DEBUG 1					; DEBUGGING BREAKPOINT
    $CALL $GTPKT				; GET AN I/O PACKET
      ON.ERROR LEAVE INITIATE			; NONE LEFT.
    LET CNTBL(R3) := R5				; SAVE UCB ADDR
 
;	.
;	.
;	
;	DEVICE-SPECIFIC INITIATION CODE GOES HERE
;
;	.
;	.
 
    LET S.CTM(R4) :B= S.ITM(R4)			; SET TIMEOUT
    LET @S.CSR(R4) := @S.CSR(R4) SET.BY #IE	; ENABLE CONTROLLER INTERRUPT
    DEBUG 1					; DEBUGGING BREAKPOINT
  END INITIATE
  $RETURN
	.PAGE
	.SBTTL POWERFAIL RECOVERY

;+
;
; POWERFAIL IS HANDLED VIA THE DEVICE TIMEOUT FACILITY AND
; THEREFORE CAUSES NO IMMEDIATE ACTION ON THE DEVICE.
; A RACE CONDITION IS THUS AVOIDED THAT COULD EXIST IN
; RESTARTING THE OPERATION.
;
; POWER FAIL CAN BE USED TO INITIALIZE THE CONTROLLER
; AND DRIVER WHEN THE DRIVER IS LOADED.
; THIS IS ENABLED BY SETTING BIT UC.PWF IN BYTE U.CTL OF THE UCB.
 
; AT THIS POINT:
;	R5 - UCB ADDRESS
;	R4 - SCB ADDRESS
;	R3 - CONTROLLER INDEX
;
;-

PROCEDURE XXPWF,GLOBAL
  BEGIN POWERFAIL
    DEBUG 2					; DEBUGGING BREAKPOINT
    IF S.PKT(R4) EQ #0				; 1ST TIME CALLED?
 
;	.
;	.
;	FIRST-TIME CODE GOES HERE
;	MAY WANT TO INITIALIZE DRIVER AND/OR
;	CONTROLLER HERE
;	.
;	.
 
    ELSE
 
;	.
;	.
;	POWERFAIL RECOVERY CODE, IF ANY
;	.
;	.
 
    END <IF>
  END POWERFAIL
  $RETURN

	.PAGE
	.SBTTL	TIMEOUT PROCESSING
;+
; DEVICE TIMEOUT 
;
; THIS SKELETON JUST CALLS $IODON TO TERMINATE THE I/O OPERATION
; AND RETURN 'DEVICE NOT READY' STATUS.
;
; AT THIS POINT:
;	R5 - UCB ADDRESS
;	R4 - SCB ADDRESS
;	R3 - CONTROLLER INDEX
;	R2 - ADDRESS OF DEVICE CSR
;	R0 - I/O STATUS CODE IE.DNR
;
;-

PROCEDURE XXOUT,GLOBAL
  BEGIN TIMEOUT
    DEBUG 1					;;; DEBUGGING BREAKPOINT
    LET @S.CSR(R4) :=  @S.CSR(R4) OFF.BY #IE	;;; DISABLE CONTROLLER INTERRUPT
    MTPS #0					;;; ALLOW PROCESSOR INTERRUPTS
 
;	.
;	.
;	DEVICE-SPECIFIC TIMEOUT CODE GOES HERE
;	MIGHT WANT TO RETRY OPERATION OR JUST
;	CALL $IODON TO TERMINATE THIS OPERATION, AS
;	BELOW:
;
;	.
;	.
;	.
 
    LET R1 := S.PKT(R4)
    LET R1 := I.PRM+4(R1) + BCR(R2)		; COMPUTE RETURN BYTE COUNT
    LET R2 := #0				; RETRY COUNT
    PUSH R4
    $CALL $IODON
    POP R4
  END TIMEOUT
  $RETURN

	.PAGE
	.SBTTL	I/O CANCEL
;+
; CANCEL I/O OPERATION-FORCE I/O TO COMPLETE IF DEVICE IS NOT READY
;
; AT THIS POINT:
;	R5 - UCB ADDRESS
;	R4 - SCB ADDRESS
;	R3 - CONTROLLER INDEX
;	R1 - TCB ADDRESS OF CURRENT TASK
;	R0 - ADDRESS OF ACTIVE I/O PACKET (ALL OTHERS HAVE BEEN PURGED)
;
;-

PROCEDURE XXCAN,GLOBAL
  BEGIN CANCEL
    DEBUG 1					;;; DEBUGGING BREAKPOINT
    IF R1 EQ I.TCB(R0)				;;; THIS TASK?
 
;	.					;;; YES.
;	.
;	.
 
    ELSE
 
;	.					;;; NO.
;	.
;	.
  
    END <IF>
  END CANCEL
  $RETURN					;;;
	.END