{  File: [Iris]<WMicro>DLion>Burdock.asm
Modification History:
	Grundler.PA:	 1-Sep-84 17:56:03: Add copyright notice
	Grundler.PA:	14-Nov-83 14:40:52: put buffer back in Buffer.asm
	Fasnacht.PA:    8-Nov-83  9:53:18}
	
{ 	Copyright (C) 1983 by Xerox Corporation.  All rights reserved.}

	
	GET	"RS232CDefs.asm"
	GET	"SysDefs.asm"
	GET	"CommonDefs.asm"

	IMP	ProcData0	;BookKeepingTask
	IMP	ProcData1	;BookKeepingTask
	IMP	ProcData2	;BookKeepingTask
	IMP	TransferProcessorCSB	;BookKeepingTask
	IMP	Wait		;Common

	IMP	BurdockIOCB		;CPSubs
	IMP	BurdockDataBuffer	;From Buffer
	IMP	ReadCPBuffer		;CPSubs
	IMP	WriteCPBuffer		;CPSubs
	IMP	StartCPReadDma		;CPSubs
	IMP	StartCPWriteDma		;CPSubs
	IMP	CheckCPDmaComplete	;CPSubs
	IMP	DoNakedNotify		;CPSubs
	IMP	ZeroCommand		;From Common

	EXP	OldReadUmbilical
	EXP	OldWriteUmbilical
	EXP	DoBurdockCmd

StartBurdockCode:
TimeOutConst	equ	0A000H	;  Approx. .25 sec


OldReadUmbilical:
{Processor Command 7:  Read a Block of Data from the other IOP via the Umbilical box

ProcData2 contains the number of bytes to transfer. ProcData1 and ProcData0 contain a Long Pointer to the user's buffer area. This area must be resident.}

	CALL	SetupOldDataPCB
	LXI	D,BurdockDataBuffer	;DE ¬ IOP Buffer address

ReadBlockLoop:
{Wait for a byte from (other) IOP Kernel. The inner loop is approximately 49 cycles (~= 17 usec). The delay is approximately 17 * TimeOutConst usec.}

	LXI	H,TimeOutConst
WaitToReadByte:
	IN	AltoPPIC
	ANI	IntBMask	;[7]
	JNZ	ReadByte	;[7]  nz => Byte is ready
	DCX	H		;[6]
	MOV	A,H		;[4]
	ORA	L		;[4]
	JNZ	WaitToReadByte	;[10]
	JMP	SetUmbilicalReturnCode

ReadByte:
	IN	AltoPPIB
	STAX	D		;Store byte in buffer
	INX	D		;Increment buffer address
	LHLD	BlockCopyCount
	DCX	H
	SHLD	BlockCopyCount
	MOV	A,H
	ORA	L
	JNZ	ReadBlockLoop

	CALL	WriteDataBuffer	; Send block to CP
	JMP	SetUmbilicalReturnCode


OldWriteUmbilical:
{Processor Command 8:  Do Write Umbilical Block Command.

ProcData2 contains the number of bytes to write in the high order byte. ProcData1 and ProcData0 contain a Long Pointer to the user's buffer area. This area must be resident.}

; Set up the PCB to transfer the data between CP virtual memory and BurdockDataBuffer.
	CALL	SetupOldDataPCB
	CALL	ReadDataBuffer	; Read block from CP

	LXI	D,BurdockDataBuffer	;DE ¬ IOP Buffer address
WriteBlockLoop:
	LDAX	D		;A ¬ next byte from buffer
	OUT	AltoPPIA	;Write data
{Now wait for the (other) IOP Kernel to grab the byte. The inner loop is approximately 49 cycles (~= 17 usec). The delay is approximately 17 * TimeOutConst usec.}

	LXI	H,TimeOutConst
WaitAckLoop:
	IN	AltoPPIC	;[11]
	ANI	IntAMask	;[7]
	JNZ	NextByte	;[7]  nz => IOP Kernel took byte
	DCX	H		;[6]
	MOV	A,H		;[4]
	ORA	L		;[4]
	JNZ	WaitAckLoop	;[10]

SetUmbilicalReturnCode:
	LHLD	BlockCopyCount	;Will be zero if	
	SHLD	ProcData0	;all bytes transferred
	JMP	TransferProcessorCSB

NextByte:
	INX	D		;Increment buffer address
	DB	opLXIH		;HL ¬ BlockCopyCount
BlockCopyCount:
	DW	0
	DCX	H
	SHLD	BlockCopyCount
	MOV	A,H
	ORA	L
	JNZ	WriteBlockLoop
	JMP	SetUmbilicalReturnCode

SetupOldDataPCB:
; Set up the PCB to transfer the data between CP virtual memory and BurdockDataBuffer.
	LHLD	ProcData1
	SHLD	BurdockDataLo
	LHLD	ProcData0
	SHLD	BurdockDataHi
	LHLD	ProcData2
	SHLD	BlockCopyCount
	INX	H		; Make the count even
	MOV	A,L
	ANI	0FEH
	MOV	L,A
	SHLD	BurdockByteCnt
	RET
	
;
BaseAddress	EQU	AltoPPI		; For IN and OUT
Status		EQU	BaseAddress+0
BufferFrmCPFull	EQU	8H
BufferToCPFull	EQU	10H
CPData		EQU	BaseAddress+1
Finger		EQU	BaseAddress+2
Contents	EQU	BaseAddress+3

{Beware of byte order: the bytes within a word get swapped}
BurdockInfo:	DS	0
BurRegister:	DS	1	; Register to use for DebuggerBoard operations
BurCommand:	DS	1	; Command byte
BurNotifyBits:	DS	2	; Naked Notify bits
BurDataLow:	DS	2	; CP buffer pointer (low)
BurDataHigh:	DS	2	; CP buffer pointer (high)
BurByteCount:	DS	2
BurdockInfoEnd:	DS	0
BurdockInfoSize	EQU	BurdockInfoEnd-BurdockInfo

CopyBurdockIocb:
	DS	2		; CP buffer pointer (low)
	DW	0		; CP buffer pointer (high)
	DW	BurdockInfoSize	; CP buffer count (bytes)
	DW	BurdockInfo	; Pointer to IOP buffer
	
ZeroBurdockIocb:
	DW	BurdockIocbLoc	; CP buffer pointer (low)
	DW	CPIOPageHi	; CP buffer pointer (high)
	DW	2		; CP buffer count (bytes)
	DW	ZeroCommand	; Pointer to IOP buffer

BurdockDataPCB:	 ; PortControlBlock for sloshing Burdock data
BurdockDataLo:	DW	0
BurdockDataHi:	DW	0
BurdockByteCnt:	DW	0
		DW	BurdockDataBuffer

DoBurdockCmd:
	LHLD	BurdockIOCB
	SHLD	CopyBurdockIocb
	LXI	H,CopyBurdockIocb
	CALL	ReadCPBuffer		; Copy over IOCB

	LHLD	BurDataLow;		; Setup data PCB
	SHLD	BurdockDataLo
	LHLD	BurDataHigh
	SHLD	BurdockDataHi
	LHLD	BurByteCount
	INX	H			; Make the count even
	MOV	A,L
	ANI	0FEH
	MOV	L,A
	SHLD	BurdockByteCnt

	LDA	BurCommand
	CPI	1
	JZ	ReadUmbilicalBlock
	CPI	2
	JZ	WriteUmbilicalBlock
	CPI	3
	JZ	ReadDebuggerBlock
	CPI	4
	JZ	WriteDebuggerBlock
	CPI	5
	JZ	ReadCPBlock
	CPI	6
	JZ	WriteCPBlock
	JMP	UnknownBurdockCommand
	

ReadUmbilicalBlock:
	CALL	WriteDataBuffer
	JMP	UnknownBurdockCommand
	
WriteUmbilicalBlock:
	CALL	ReadDataBuffer
	JMP	UnknownBurdockCommand

ReadDebuggerBlock:
	LDA	BurRegister
	OUT	Finger
	LXI	D,BurdockDataBuffer	;DE ¬ IOP Buffer address
ReadDebuggerBlockLoop:
	IN	Contents
	STAX	D			; Store byte in buffer
	INX	D			; Increment buffer address
	LHLD	BurByteCount
	DCX	H
	SHLD	BurByteCount
	MOV	A,H
	ORA	L
	JNZ	ReadDebuggerBlockLoop
	CALL	WriteDataBuffer
	JMP	FinishBurdockCommand

WriteDebuggerBlock:
	CALL	ReadDataBuffer
	LDA	BurRegister
	OUT	Finger
	LXI	D,BurdockDataBuffer	; DE ¬ IOP Buffer address
WriteDebuggerBlockLoop:
	LDAX	D			; Load byte from buffer
	OUT	Contents
	INX	D			; Increment buffer address
	LHLD	BurByteCount
	DCX	H
	SHLD	BurByteCount
	MOV	A,H
	ORA	L
	JNZ	WriteDebuggerBlockLoop
	JMP	FinishBurdockCommand

ReadCPBlock:
	LXI	D,BurdockDataBuffer
ReadCPBlockLoop:
	LXI	H,TimeOutConst
ReadCPBlockWait:
	DCX	H
	MOV	A,H
	ORA	L
	JZ	Timeout       
	IN	Status
	ANI	BufferFrmCPFull
	JZ	ReadCPBlockWait
	IN	CPData
	STAX	D
	INX	D
	LHLD	BurByteCount
	DCX	H
	SHLD	BurByteCount
	MOV	A,H
	ORA	L
	JNZ	ReadCPBlockLoop
	CALL	WriteDataBuffer
	JMP	FinishBurdockCommand

WriteCPBlock:
	CALL	ReadDataBuffer
	LXI	D,BurdockDataBuffer
WriteCPBlockLoop:
	LDAX	D			; A ¬ next byte from buffer
	OUT	CPData
	LXI	H,TimeOutConst
WriteCPBlockWait:
	DCX	H
	MOV	A,H
	ORA	L
	JZ	Timeout       
	IN	Status
	ANI	BufferToCPFull
	JNZ	WriteCPBlockWait
	INX	D
	LHLD	BurByteCount
	DCX	H
	SHLD	BurByteCount
	MOV	A,H
	ORA	L
	JNZ	WriteCPBlockLoop
	JMP	FinishBurdockCommand

UnknownBurdockCommand:
	XRA	A
	STA	BurCommand		; Smash command byte for error marker

Timeout:
FinishBurdockCommand:
	LXI	H,CopyBurdockIocb	; Write back updated byte count
	CALL	WriteCPBuffer
	LXI	H,ZeroBurdockIocb
	CALL	WriteCPBuffer
	LHLD	BurNotifyBits
	JMP	DoNakedNotify		; and RET


ReadDataBuffer:
	LXI	H,BurdockDataPCB
	CALL	StartCPReadDma
	JMP	WaitForTransfer

WriteDataBuffer:
	LXI	H,BurdockDataPCB
	CALL	StartCPWriteDma
WaitForTransfer:
	CALL	CheckCPDmaComplete
	JZ	WaitForTransfer
	RET

	END	Burdock