;	mydriver.a
;
;	Copyright (C) 2004 Paul C. Pratt
;
;	You can redistribute this file and/or modify it under the terms
;	of version 2 of the GNU General Public License as published by
;	the Free Software Foundation.  You should have received a copy
;	of the license along with this file; see the file COPYING.
;
;	This file is distributed in the hope that it will be useful,
;	but WITHOUT ANY WARRANTY; without even the implied warranty of
;	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;	license for more details.

; most of this is adapted from sample source code from Apple.

FakeSonyDriver MAIN EXPORT
		BLANKS  ON
		STRING  ASIS

kqLink        EQU  0
kqType        EQU  4
kioTrap       EQU  6
kioCmdAddr    EQU  8
kioCompletion EQU 12
kioResult     EQU 16
kioNamePtr    EQU 18
kioVRefNum    EQU 22
kioRefNum     EQU 24
kcsCode       EQU 26
kcsParam      EQU 28
kioBuffer     EQU 32 ; Buffer to store data into
kioReqCount   EQU 36 ; Requested Number of Bytes
kioActCount   EQU 40 ; Actual Number of Bytes obtained
kioPosMode    EQU 44 ; Positioning Mode
kioPosOffset  EQU 46 ; Position Offset

killCode   EQU 1 ; KillIO requested
noQueueBit EQU 9 ; trap word modifier
JIODone    EQU $08FC

kCmndSonyPrime    EQU $0001
kCmndSonyControl  EQU $0002
kCmndSonyStatus   EQU $0003
kCmndSonyClose    EQU $0004
kCmndSonyOpenA    EQU $0005
kCmndSonyOpenB    EQU $0006
kCmndSonyOpenC    EQU $0007
kCmndSonyMount    EQU $0008

DHeader
DFlags   DC.W  $4F00              ; need lock, responds to all requests
DDelay   DC.W  0                  ; none
DEMask   DC.W  0                  ; DA event mask
DMenu    DC.W  0                  ; no menu
         DC.W  DOpen - DHeader    ; offset to Open
         DC.W  DPrime - DHeader   ; offset to Prime
         DC.W  DControl - DHeader ; offset to Control
         DC.W  DStatus - DHeader  ; offset to Status
         DC.W  DClose - DHeader   ; offset to Close
Name     DC.B  5 ; length of name
         DC.B  '.Sony'
         ALIGN 2                  ; word alignment

DPrime
	MOVEM.L    A0-A1, -(SP)    ; push ParmBlkPtr, DCtlPtr for C
	SUBQ       #2, A7 ; result code
	MOVE.W     #kCmndSonyPrime, -(A7)
	BRA.B      DPrimeStatusCommon

DControl
	MOVEM.L    A0-A1, -(SP)    ; push ParmBlkPtr, DCtlPtr for C
	SUBQ       #2, A7 ; result code
	MOVE.W     #kCmndSonyControl, -(A7)

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D0 ; save result code
	MOVEM.L    (SP)+, A0-A1    ; restore ParmBlkPtr, DCtlPtr
	CMPI.W     #killCode,kcsCode(A0) ; test for KillIO call (special case)
	BNE.B      IOReturn
	RTS                     ; KillIO must always return via RTS

DStatus
	MOVEM.L    A0-A1, -(SP)    ; push ParmBlkPtr, DCtlPtr for C
	SUBQ       #2, A7 ; result code
	MOVE.W     #kCmndSonyStatus, -(A7)
DPrimeStatusCommon

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D0 ; save result code
	MOVEM.L    (SP)+, A0-A1    ; restore ParmBlkPtr, DCtlPtr

IOReturn
	MOVE.W   kioTrap(A0),D1
	BTST     #noQueueBit,D1 ; immediate calls are not queued, and must RTS
	BEQ.B    @Queued        ; branch if queued

@NotQueued
	TST.W    D0             ; test asynchronous return result
	BLE.B    @ImmedRTS      ; result must be <= 0
	CLR.W    D0             ; "in progress" result (> 0) not passed back

@ImmedRTS
	MOVE.W   D0,kioResult(A0)   ; for immediate calls you must explicitly
	                            ; place the result in the ioResult field
	RTS

@Queued
	TST.W    D0             ; test asynchronous return result
	BLE.B    @MyIODone      ; I/O is complete if result <= 0
	CLR.W    D0             ; "in progress" result (> 0) not passed back
	RTS

@MyIODone
	MOVE.L   JIODone,-(SP)  ; push IODone jump vector onto stack
	RTS

DClose
	MOVEM.L    A0-A1, -(SP)    ; push ParmBlkPtr, DCtlPtr for C
	SUBQ       #2, A7 ; result code
	MOVE.W     #kCmndSonyClose, -(A7)

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D0 ; save result code
	MOVEM.L    (SP)+, A0-A1    ; restore ParmBlkPtr, DCtlPtr
	RTS

DUpdate
	MOVEM.L    D0-D2/A0-A1,-(SP)
	MOVE.L     20(A7),D0 ; data = what was on top of stack before 5 registers pushed

	SUBQ       #4, A7 ; room for eventMsg
	MOVE.L     D0,-(A7) ; data
	SUBQ       #2, A7 ; room for result code
	MOVE.W     #kCmndSonyMount, -(A7)

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D1 ; result code
	ADDQ       #4, A7 ; skip over data
	MOVE.L     (A7)+, D0 ; eventMsg
	TST.W      D1 ; result code
	BNE.S      @1
	MOVEA.W    #$0007,A0
	DC.W       $A02F ; _PostEvent
@1

	MOVEM.L    (SP)+,D0-D2/A0-A1
	ADDA.W     #4,A7          ; remove arguments from stack
	RTE

MyAddDrive64k

; This is only needed for the 64k ROM.

DrvQHdr EQU 776
RomBase EQU $00400000

	Move.L    D0,6(A0)
	Lea.L     (DrvQHdr),A1
	Jmp       (RomBase + 2848)


NullTaskProc
	RTS

DOpen
	MOVEM.L    D3-D7/A3,-(A7)
	MOVEM.L    A0-A1, -(SP)    ; push ParmBlkPtr, DCtlPtr for C

	SUBQ       #6, A7 ; room for result code, L
	MOVE.W     #kCmndSonyOpenA, -(A7)

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D0 ; result code
	MOVE.L     (A7)+, D7 ; L

	CMPI.W     #$FFCF,D0
	BNE.S      @1
	; driver already open, change to no error and leave
	CLR.W      D0
	BRA        @2
@1
	TST.W      D0
	BNE        @2
	MOVE.L     D7,D0
	DC.W       $A71E ; _NewPtr    ,Sys,Clear
	MOVEA.L    A0,A3
	MOVE.L     A3,D0
	BEQ        @6

	SUBA       #16, A7 ; room for various results
	MOVE.L     A3, -(A7)
	MOVE.L     D7, -(A7)
	SUBQ       #2, A7 ; room for result code
	MOVE.W     #kCmndSonyOpenB, -(A7)

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D0 ; result code
	ADDA.W     #8, A7
	MOVE.L     (A7)+, D7 ; dvl
	MOVEQ      #$00, D3
	MOVE.W     (A7)+, D3 ; step
	MOVE.W     (A7)+, D4 ; n
	MOVE.W     (A7)+, D6 ; i
	MOVE.W     (A7)+, D5 ; driver
	MOVEA.L    (A7)+, A3 ; NullTask

	TST.W      D0
	BNE.S      @2

	MOVE.L     A3,D0
	BEQ.S      @3

	; There is apparently a bug in the time manager
	; in System 6.0.8, which will cause a crash
	; if there are no installed time
	; tasks. So create a time task, since
	; real disk driver does.

	LEA        NullTaskProc,A0     ; id: 102
	MOVE.L     A0,$0006(A3)
	MOVEA.L    A3,A0
	DC.W       $A058 ; _InsTime
	BRA.S      @4
@3
	LEA        MyAddDrive64k,A0    ; id: 106
	MOVE.W     #$A04E,D0
	DC.W       $A047 ; _SetTrapAddress
	BRA.S      @4
@5
	MOVEA.L    D7,A0

	MOVE.W     D6,D0 ; drive number in high word
	SWAP       D0
	MOVE.W     D5,D0 ; driver in low word

	DC.W       $A04E ; _AddDrive
	ADD.L      D3,D7
	ADDQ.W     #$1,D6
@4
	DBF        D4, @5

	PEA        DUpdate
	SUBQ       #2, A7 ; room for result code
	MOVE.W     #kCmndSonyOpenC, -(A7)

	LEA        TailData, A0
	MOVE.L     (A0)+, -(A7)
	MOVEA.L    (A0), A0
	MOVE.L     A7, (A0)

	ADDA.W     #6, A7
	MOVE.W     (A7)+, D0 ; result code
	ADDA.W     #4, A7

@2
	; result code should be in D0 when reach here

	MOVEM.L    (A7)+, A0-A1    ; restore ParmBlkPtr, DCtlPtr
	MOVEM.L    (A7)+, D3-D7/A3

	RTS                     ; open is always immediate, must return via RTS
@6
	; _NewPtr failed
	MOVE.W     #-1, D0
	BRA.S      @2

TailData

		ENDMAIN

		END