;==========================================================================								
;
;	File:		SIMMachine.a
;
;	Contains:	Misc. routines for SIM SCSI State Machine
;
;	Written by:	Paul Wolf
;
;	Copyright:	© 1990-1993 by Apple Computer, Inc., all rights reserved.
;
;	Change History (most recent first):
;
;	  <SM12>	11/16/93	SAM		Include HardwarePrivateEqu.a
;	  <SM11>	10/14/93	pdw		<MC> roll-in.
;	   <MC2>	10/12/93	pdw		Added support for Synchronous data transfers, rewrote State
;									Machine, message handling etc.
;	  <SM10>	  9/9/93	pdw		Lots of little changes.  Name changes, temporary cache_bug
;									stuff.
;	   <SM9>	  7/8/93	pdw		Changed recording data for stack switching events to help Kurt
;									with StkLowPt problem.
;	   <SM8>	 6/29/93	pdw		Massive checkins: Change asynchronicity mechanism to CallMachine
;									stack switching mechanism.  Adding support for Cold Fusion.
;									Rearranging HW/SW Init code. Some code optimizations.
;	   <SM7>	  5/5/93	PW		Converted names to meanies-friendly names.  Updated with latest
;									from Ludwig stuff.
;	   <LW3>	  5/1/93	PW		Got rid of RECORD_ON and RECORD_rCMD definitions (should only be
;									in Debug.a now.
;	   <SM6>	  2/9/93	PW		Removed some PDM debug stuff that's not needed.
;	   <SM5>	 1/31/93	PW		Update from the latest of Ludwig. Also changes required for PDM
;									(will update Ludwig with these as needed myself).
;	   <SM4>	11/20/92	DCB		Removed VM Stuff and put it into SCSIGlue.a
;	   <SM3>	10/30/92	DCB		Stopped recording VM calls
;	   <SM2>	 10/8/92	PW		Removed lots of unused code.
;
;==========================================================================								


			MACHINE		MC68020			; '020-level
			BLANKS		ON				; assembler accepts spaces & tabs in operand field
			PRINT		OFF				; do not send subsequent lines to the listing file
										;	don't print includes

	
			INCLUDE		'SysEqu.a'				; for StkLowPt
			INCLUDE		'HardwarePrivateEqu.a'
			INCLUDE		'Traps.a'				; for _DebugStr
			INCLUDE		'Debug.a'				; for NAME
			INCLUDE		'ACAM.a'
			INCLUDE		'HALc96equ.a'
			

			PRINT		ON				; do send subsequent lines to the listing files
			CASE		OBJECT

			IMPORT		RecordEvent
			
			
;==========================================================================


;**************************************************************************
;
;	CallMachine - 
;
;==========================================================================

CallMachine		PROC	EXPORT

	IMPORT	TheMachine
	IMPORT	FreeMachine
	WITH	HALc96GlobalRecord
;………………………………………………………………………………………………………………………………………………………………………………………………………………………
; Switch to SCSI stack, suspending the main "thread".
;	then call the selected routine
;	then switch back to the previous "thread" which may be the main thread or 
;	it may be the interrupt thread (i.e. we're finally completing a request)
;………………………………………………………………………………………………………………………………………………………………………………………………………………………

			move.l	A5, -(sp)						; save caller's A5
			
			move.l	8(sp), A0						; get SIMg parameter
			move.l	(A0), A5						; get HALg
			
			DisableSCSIIRQ							; disable ints before we go down into Machine

			IF STACK_RECORD_ON THEN
				pea		'>>  '
				move.l	StkLowPt, -(sp)
				bsr		RecordEvent
				addq.l	#8, sp
			ENDIF
			
			movem.l	D3-D7/A2-A6, -(sp)
			bsr.s	PrivateCallMachine		; MAGIC stack change here!!
			movem.l	(sp)+, D3-D7/A2-A6
			
			IF STACK_RECORD_ON THEN
				pea		'<<  '
				move.l	StkLowPt, -(sp)
				bsr		RecordEvent
				addq.l	#8, sp
			ENDIF
			
			EnableSCSIIRQ						; enable ints after we come back out

			move.l	(sp)+, A5					; restore caller's A5
			rts
			
		NAME 'CallMachine'
			
;……………………………………………………………………………………………………………………………………………………

PrivateCallMachine

; Switch to SCSI stack ……………………………………

			IF STACK_RECORD_ON THEN
				pea		'  >>'
				move.l	StkLowPt, -(sp)				
				bsr		RecordEvent
				addq.l	#8, sp
			ENDIF

			move.l	StkLowPt, publicStkLowPt(A5)	; remember old StkLowPt
			clr.l	StkLowPt						; and disable stack sniffer
			move.l	sp, publicSP(A5)				; suspend main thread
			IF DEBUGGING THEN
				move.b	#1, privStackState(A5)
			ENDIF
			move.l	privStackTop(A5), sp			; create SCSI thread

			IF STACK_RECORD_ON THEN
				pea		'>Mch'
				move.l	StkLowPt, -(sp)				
				bsr		RecordEvent
				addq.l	#8, sp
			ENDIF

; Call the State Machine ……………………………………

;	TheMachine( OSErr * finalStatus, SIM_IO ** completedIO, SIMglobals * SIMg)

			subq.l	#6, sp						; allocate room for completedIO & finalStatus

			move.l	A0, -(sp)					; pass SIMg into Machine
			pea		4(sp)						; sp=SIMg,completedIO
			pea		12(sp)						; sp=*completedIO,SIMg,completedIO,finalStatus

			bsr		TheMachine

			lea		8(sp), sp					; get rid of parameters except for...
			move.l	(sp)+, A0					; ...SIMg
			move.l	(sp)+, A1					; get completedIO
			moveq.l	#0, D1
			move.w	(sp)+, D1					; get finalStatus
			
; Return to previous stack ……………………………………

			IF STACK_RECORD_ON THEN
				pea		'<Mch'
				move.l	StkLowPt, -(sp)				
				bsr		RecordEvent
				addq.l	#8, sp
			ENDIF

			IF DEBUGGING THEN
				move.b	#4, privStackState(A5)
			ENDIF
			move.l	publicSP(A5), sp				; resume previous thread
			move.l	publicStkLowPt(A5), StkLowPt	; resume stack sniffing
			
			IF STACK_RECORD_ON THEN
				pea		'  <<'
				move.l	StkLowPt, -(sp)				
				bsr		RecordEvent
				addq.l	#8, sp
			ENDIF

			tst.w	D0								; what did TheMachine return?
			beq.s	@exit							; freeTheMachine? no -> rts (old API)
			move.l	A0, -(sp)						; SIMg
			move.l	A1, -(sp)						; ioPtr
			move.l	D1, -(sp)						; finalStatus
			bsr		FreeMachine
			lea		12(sp), sp						; get rid of parameters
@exit			
			rts

		NAME 'PrivateCallMachine'

	ENDWITH
	
;**************************************************************************
;
;	BlockInterrupts, UnblockInterrupts - 
;
;==========================================================================

BlockInterrupts		PROC	EXPORT

			move.w	SR, D0
			ori.w	#$0700,SR			; disable all ints
			rts
			
		NAME 'BlockInterrupts'

				ENDP
				
;……………………………………………………………………………………………………………………………………………………

UnblockInterrupts		PROC	EXPORT

			move.w	6(sp), SR
			rts
			
		NAME 'UnblockInterrupts'

				ENDP




		END