card.resource wtf

mark_k · 12 November 2017, 13:26

I've been looking at the code of card.resource after reading this thread. I checked v37.11 in A600 Kickstart 37.350 and v40.4 in A600 Kickstart 40.63. [There's also a loadable (with LoadModule) card.resource v43.1 linked in this post. Is that official? Where did it come from?]

Are there any known bugs/problems with PCMCIA cards (i.e. card.resource) in Kickstart 3.1? Because there definitely seems to be a bug in versions 40.4 and 43.1.

The initialisation routine is supposed to open timer.device. v37.11 code does that, but in v40.4:

Code:

	LEA	(ReplyPort-LibBase,A5),A0
	MOVEA.L	A0,A3
	MOVEQ	#IOTV_SIZE,D0
	JSR	(_LVOCreateIORequest,A6)
	MOVE.L	D0,(_SomeIORequest-LibBase,A5)
	MOVEA.L	D0,A1	;IORequest
	SUBA.L	A0,A0	;Device name pointer 0!!! Should point to "timer.device"
	MOVEQ	#UNIT_VBLANK,D0	;Unit
	MOVEQ	#0,D1	;Flags
	JSR	(_LVOOpenDevice,A6)

	LEA	(TaskStruct-LibBase,A5),A1
	MOVE.L	A1,(MP_SIGTASK,A3)

Then later on the task code issues TR_ADDREQUEST:

Code:

TaskCode
	MOVEA.L	(4,SP),A5
	MOVEA.L	(_SysBase-LibBase,A5),A6
	MOVEQ	#31,D0
	JSR	(_LVOAllocSignal,A6)
	BRA.B	lbC000678

lbC000644
	BSR.W	lbC000586
	SUBQ.B	#1,(IDNestCnt,A6)
	BGE.B	lbC000656

	MOVE.W	#$C000,(_custom+intena).L
lbC000656
	BSET	#1,(lbB001022-LibBase,A5)
	BNE.B	lbC000678

	MOVEA.L	(_SomeIORequest-LibBase,A5),A1
	MOVE.W	#TR_ADDREQUEST,(IO_COMMAND,A1)
	CLR.L	(IOTV_TIME,A1)
	MOVE.L	#100000,(IOTV_TIME+TV_MICRO,A1)	;1/10 second
	JSR	(_LVOSendIO,A6)

lbC000678
	MOVE.L	#$80000000,D0
	JSR	(_LVOWait,A6)
	LEA	(ReplyPort-LibBase,A5),A0
	JSR	(_LVOGetMsg,A6)
	TST.L	D0
	BEQ.B	lbC000656

	BCLR	#1,(lbB001022-LibBase,A5)
	LEA	(SomeList-LibBase,A5),A0

How can that not crash?

phx · 14 November 2017, 10:50

Quote:

Originally Posted by mark_k

The initialisation routine is supposed to open timer.device. v37.11 code does that, but in v40.4:

Code:

    LEA    (ReplyPort-LibBase,A5),A0
    MOVEA.L    A0,A3
    MOVEQ    #IOTV_SIZE,D0
    JSR    (_LVOCreateIORequest,A6)
    MOVE.L    D0,(_SomeIORequest-LibBase,A5)
    MOVEA.L    D0,A1    ;IORequest
    SUBA.L    A0,A0    ;Device name pointer 0!!! Should point to "timer.device"
    MOVEQ    #UNIT_VBLANK,D0    ;Unit
    MOVEQ    #0,D1    ;Flags
    JSR    (_LVOOpenDevice,A6)

That's a shortcut used in the ROM to eliminate the many references to "timer.device" and "input.device" strings (probably to save space?).
OpenDevice() with name=0 means "timer.device" and name=1 means "input.device".

mark_k · 14 November 2017, 14:19

Thanks, I didn't know that! Do you know whether that behaviour was documented anywhere?

phx · 14 November 2017, 17:46

I don't remember having seen it documented anyhere. I discovered that by looking into the exec/OpenDevice function.

In any case it is not in the official Autodocs.

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14 November 2017, 14:19	#3
mark_k Registered User Join Date: Aug 2004 Location: Posts: 3,335	Thanks, I didn't know that! Do you know whether that behaviour was documented anywhere?

14 November 2017, 17:46	#4
phx Natteravn Join Date: Nov 2009 Location: Herford / Germany Posts: 2,496	I don't remember having seen it documented anyhere. I discovered that by looking into the exec/OpenDevice function. In any case it is not in the official Autodocs.

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