ncr.c

国产CPU－龙芯（loongson)BIOS源代码

	/*
	**      And try to select this target.
	*/
	SCR_SEL_TBL_ATN ^ offsetof (struct dsb, select),
		PADDR (reselect),

	/*
	**	Now there are 4 possibilities:
	**
	**	(1) The ncr looses arbitration.
	**	This is ok, because it will try again,
	**	when the bus becomes idle.
	**	(But beware of the timeout function!)
	**
	**	(2) The ncr is reselected.
	**	Then the script processor takes the jump
	**	to the RESELECT label.
	**
	**	(3) The ncr completes the selection.
	**	Then it will execute the next statement.
	**
	**	(4) There is a selection timeout.
	**	Then the ncr should interrupt the host and stop.
	**	Unfortunately, it seems to continue execution
	**	of the script. But it will fail with an
	**	IID-interrupt on the next WHEN.
	*/

	SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_IN)),
		0,

	/*
	**	Save target id to ctest0 register
	*/

	SCR_FROM_REG (sdid),
		0,
	SCR_TO_REG (ctest0),
		0,
	/*
	**	Send the IDENTIFY and SIMPLE_TAG messages
	**	(and the M_X_SYNC_REQ message)
	*/
	SCR_MOVE_TBL ^ SCR_MSG_OUT,
		offsetof (struct dsb, smsg),
#ifdef undef /* XXX better fail than try to deal with this ... */
	SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_OUT)),
		-16,
#endif
	SCR_CLR (SCR_ATN),
		0,
	SCR_COPY (1),
		RADDR (sfbr),
		NADDR (lastmsg),
	/*
	**	Selection complete.
	**	Next time use the next slot.
	*/
	SCR_COPY (4),
		RADDR (scratcha),
		PADDR (startpos),
}/*-------------------------< PREPARE >----------------------*/,{
	/*
	**      The ncr doesn't have an indirect load
	**	or store command. So we have to
	**	copy part of the control block to a
	**	fixed place, where we can access it.
	**
	**	We patch the address part of a
	**	COPY command with the DSA-register.
	*/
	SCR_COPY_F (4),
		RADDR (dsa),
		PADDR (loadpos),
	/*
	**	then we do the actual copy.
	*/
	SCR_COPY (sizeof (struct head)),
	/*
	**	continued after the next label ...
	*/

}/*-------------------------< LOADPOS >---------------------*/,{
		0,
		NADDR (header),
	/*
	**      Mark this ccb as not scheduled.
	*/
	SCR_COPY (8),
		PADDR (idle),
		NADDR (header.launch),
	/*
	**      Set a time stamp for this selection
	*/
	SCR_COPY (sizeof (struct timeval)),
		KVAR (KVAR_TIME),
		NADDR (header.stamp.select),
	/*
	**      load the savep (saved pointer) into
	**      the TEMP register (actual pointer)
	*/
	SCR_COPY (4),
		NADDR (header.savep),
		RADDR (temp),
	/*
	**      Initialize the status registers
	*/
	SCR_COPY (4),
		NADDR (header.status),
		RADDR (scr0),

}/*-------------------------< PREPARE2 >---------------------*/,{
	/*
	**      Load the synchronous mode register
	*/
	SCR_COPY (1),
		NADDR (sync_st),
		RADDR (sxfer),
	/*
	**      Load the wide mode and timing register
	*/
	SCR_COPY (1),
		NADDR (wide_st),
		RADDR (scntl3),
	/*
	**	Initialize the msgout buffer with a NOOP message.
	*/
	SCR_LOAD_REG (scratcha, M_NOOP),
		0,
	SCR_COPY (1),
		RADDR (scratcha),
		NADDR (msgout),
	SCR_COPY (1),
		RADDR (scratcha),
		NADDR (msgin),
	/*
	**	Message in phase ?
	*/
	SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
		PADDR (dispatch),
	/*
	**	Extended or reject message ?
	*/
	SCR_FROM_REG (sbdl),
		0,
	SCR_JUMP ^ IFTRUE (DATA (M_EXTENDED)),
		PADDR (msg_in),
	SCR_JUMP ^ IFTRUE (DATA (M_REJECT)),
		PADDRH (msg_reject),
	/*
	**	normal processing
	*/
	SCR_JUMP,
		PADDR (dispatch),
}/*-------------------------< SETMSG >----------------------*/,{
	SCR_COPY (1),
		RADDR (scratcha),
		NADDR (msgout),
	SCR_SET (SCR_ATN),
		0,
}/*-------------------------< CLRACK >----------------------*/,{
	/*
	**	Terminate possible pending message phase.
	*/
	SCR_CLR (SCR_ACK),
		0,

}/*-----------------------< DISPATCH >----------------------*/,{
	SCR_FROM_REG (HS_REG),
		0,
	SCR_INT ^ IFTRUE (DATA (HS_NEGOTIATE)),
		SIR_NEGO_FAILED,
	/*
	**	remove bogus output signals
	*/
	SCR_REG_REG (socl, SCR_AND, CACK|CATN),
		0,
	SCR_RETURN ^ IFTRUE (WHEN (SCR_DATA_OUT)),
		0,
	SCR_RETURN ^ IFTRUE (IF (SCR_DATA_IN)),
		0,
	SCR_JUMP ^ IFTRUE (IF (SCR_MSG_OUT)),
		PADDR (msg_out),
	SCR_JUMP ^ IFTRUE (IF (SCR_MSG_IN)),
		PADDR (msg_in),
	SCR_JUMP ^ IFTRUE (IF (SCR_COMMAND)),
		PADDR (command),
	SCR_JUMP ^ IFTRUE (IF (SCR_STATUS)),
		PADDR (status),
	/*
	**      Discard one illegal phase byte, if required.
	*/
	SCR_LOAD_REG (scratcha, XE_BAD_PHASE),
		0,
	SCR_COPY (1),
		RADDR (scratcha),
		NADDR (xerr_st),
	SCR_JUMPR ^ IFFALSE (IF (SCR_ILG_OUT)),
		8,
	SCR_MOVE_ABS (1) ^ SCR_ILG_OUT,
		NADDR (scratch),
	SCR_JUMPR ^ IFFALSE (IF (SCR_ILG_IN)),
		8,
	SCR_MOVE_ABS (1) ^ SCR_ILG_IN,
		NADDR (scratch),
	SCR_JUMP,
		PADDR (dispatch),

}/*-------------------------< NO_DATA >--------------------*/,{
	/*
	**	The target wants to tranfer too much data
	**	or in the wrong direction.
	**      Remember that in extended error.
	*/
	SCR_LOAD_REG (scratcha, XE_EXTRA_DATA),
		0,
	SCR_COPY (1),
		RADDR (scratcha),
		NADDR (xerr_st),
	/*
	**      Discard one data byte, if required.
	*/
	SCR_JUMPR ^ IFFALSE (WHEN (SCR_DATA_OUT)),
		8,
	SCR_MOVE_ABS (1) ^ SCR_DATA_OUT,
		NADDR (scratch),
	SCR_JUMPR ^ IFFALSE (IF (SCR_DATA_IN)),
		8,
	SCR_MOVE_ABS (1) ^ SCR_DATA_IN,
		NADDR (scratch),
	/*
	**      .. and repeat as required.
	*/
	SCR_CALL,
		PADDR (dispatch),
	SCR_JUMP,
		PADDR (no_data),
}/*-------------------------< CHECKATN >--------------------*/,{
	/*
	**	If AAP (bit 1 of scntl0 register) is set
	**	and a parity error is detected,
	**	the script processor asserts ATN.
	**
	**	The target should switch to a MSG_OUT phase
	**	to get the message.
	*/
	SCR_FROM_REG (socl),
		0,
	SCR_JUMP ^ IFFALSE (MASK (CATN, CATN)),
		PADDR (dispatch),
	/*
	**	count it
	*/
	SCR_REG_REG (PS_REG, SCR_ADD, 1),
		0,
	/*
	**	Prepare a M_ID_ERROR message
	**	(initiator detected error).
	**	The target should retry the transfer.
	*/
	SCR_LOAD_REG (scratcha, M_ID_ERROR),
		0,
	SCR_JUMP,
		PADDR (setmsg),

}/*-------------------------< COMMAND >--------------------*/,{
	/*
	**	If this is not a GETCC transfer ...
	*/
	SCR_FROM_REG (SS_REG),
		0,
/*<<<*/	SCR_JUMPR ^ IFTRUE (DATA (S_CHECK_COND)),
		28,
	/*
	**	... set a timestamp ...
	*/
	SCR_COPY (sizeof (struct timeval)),
		KVAR (KVAR_TIME),
		NADDR (header.stamp.command),
	/*
	**	... and send the command
	*/
	SCR_MOVE_TBL ^ SCR_COMMAND,
		offsetof (struct dsb, cmd),
	SCR_JUMP,
		PADDR (dispatch),
	/*
	**	Send the GETCC command
	*/
/*>>>*/	SCR_MOVE_TBL ^ SCR_COMMAND,
		offsetof (struct dsb, scmd),
	SCR_JUMP,
		PADDR (dispatch),

}/*-------------------------< STATUS >--------------------*/,{
	/*
	**	set the timestamp.
	*/
	SCR_COPY (sizeof (struct timeval)),
		KVAR (KVAR_TIME),
		NADDR (header.stamp.status),
	/*
	**	If this is a GETCC transfer,
	*/
	SCR_FROM_REG (SS_REG),
		0,
/*<<<*/	SCR_JUMPR ^ IFFALSE (DATA (S_CHECK_COND)),
		40,
	/*
	**	get the status
	*/
	SCR_MOVE_ABS (1) ^ SCR_STATUS,
		NADDR (scratch),
	/*
	**	Save status to scsi_status.
	**	Mark as complete.
	**	And wait for disconnect.
	*/
	SCR_TO_REG (SS_REG),
		0,
	SCR_REG_REG (SS_REG, SCR_OR, S_SENSE),
		0,
	SCR_LOAD_REG (HS_REG, HS_COMPLETE),
		0,
	SCR_JUMP,
		PADDR (checkatn),
	/*
	**	If it was no GETCC transfer,
	**	save the status to scsi_status.
	*/
/*>>>*/	SCR_MOVE_ABS (1) ^ SCR_STATUS,
		NADDR (scratch),
	SCR_TO_REG (SS_REG),
		0,
	/*
	**	if it was no check condition ...
	*/
	SCR_JUMP ^ IFTRUE (DATA (S_CHECK_COND)),
		PADDR (checkatn),
	/*
	**	... mark as complete.
	*/
	SCR_LOAD_REG (HS_REG, HS_COMPLETE),
		0,
	SCR_JUMP,
		PADDR (checkatn),

}/*-------------------------< MSG_IN >--------------------*/,{
	/*
	**	Get the first byte of the message
	**	and save it to SCRATCHA.
	**
	**	The script processor doesn't negate the
	**	ACK signal after this transfer.
	*/
	SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
		NADDR (msgin[0]),
	/*
	**	Check for message parity error.
	*/
	SCR_TO_REG (scratcha),
		0,
	SCR_FROM_REG (socl),
		0,
	SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
		PADDRH (msg_parity),
	SCR_FROM_REG (scratcha),
		0,
	/*
	**	Parity was ok, handle this message.
	*/
	SCR_JUMP ^ IFTRUE (DATA (M_COMPLETE)),
		PADDR (complete),
	SCR_JUMP ^ IFTRUE (DATA (M_SAVE_DP)),
		PADDR (save_dp),
	SCR_JUMP ^ IFTRUE (DATA (M_RESTORE_DP)),
		PADDR (restore_dp),
	SCR_JUMP ^ IFTRUE (DATA (M_DISCONNECT)),
		PADDR (disconnect),
	SCR_JUMP ^ IFTRUE (DATA (M_EXTENDED)),
		PADDRH (msg_extended),
	SCR_JUMP ^ IFTRUE (DATA (M_NOOP)),
		PADDR (clrack),
	SCR_JUMP ^ IFTRUE (DATA (M_REJECT)),
		PADDRH (msg_reject),
	SCR_JUMP ^ IFTRUE (DATA (M_IGN_RESIDUE)),
		PADDRH (msg_ign_residue),
	/*
	**	Rest of the messages left as
	**	an exercise ...
	**
	**	Unimplemented messages:
	**	fall through to MSG_BAD.
	*/
}/*-------------------------< MSG_BAD >------------------*/,{
	/*
	**	unimplemented message - reject it.
	*/
	SCR_INT,
		SIR_REJECT_SENT,
	SCR_LOAD_REG (scratcha, M_REJECT),
		0,
	SCR_JUMP,
		PADDR (setmsg),

}/*-------------------------< COMPLETE >-----------------*/,{
	/*
	**	Complete message.
	**
	**	If it's not the get condition code,
	**	copy TEMP register to LASTP in header.
	*/
	SCR_FROM_REG (SS_REG),
		0,
/*<<<*/	SCR_JUMPR ^ IFTRUE (MASK (S_SENSE, S_SENSE)),
		12,
	SCR_COPY (4),
		RADDR (temp),
		NADDR (header.lastp),
/*>>>*/	/*
	**	When we terminate the cycle by clearing ACK,
	**	the target may disconnect immediately.
	**
	**	We don't want to be told of an
	**	"unexpected disconnect",
	**	so we disable this feature.
	*/
	SCR_REG_REG (scntl2, SCR_AND, 0x7f),
		0,
	/*
	**	Terminate cycle ...
	*/
	SCR_CLR (SCR_ACK|SCR_ATN),
		0,
	/*
	**	... and wait for the disconnect.
	*/
	SCR_WAIT_DISC,
		0,
}/*-------------------------< CLEANUP >-------------------*/,{
	/*
	**      dsa:    Pointer to ccb
	**	      or xxxxxxFF (no ccb)
	**
	**      HS_REG:   Host-Status (<>0!)
	*/
	SCR_FROM_REG (dsa),
		0,
	SCR_JUMP ^ IFTRUE (DATA (0xff)),
		PADDR (signal),
	/*
	**      dsa is valid.
	**	save the status registers
	*/
	SCR_COPY (4),
		RADDR (scr0),
		NADDR (header.status),
	/*
	**	and copy back the header to the ccb.
	*/
	SCR_COPY_F (4),
		RADDR (dsa),
		PADDR (cleanup0),
	SCR_COPY (sizeof (struct head)),
		NADDR (header),
}/*-------------------------< CLEANUP0 >--------------------*/,{
		0,

	/*
	**	If command resulted in "check condition"
	**	status and is not yet completed,
	**	try to get the condition code.
	*/
	SCR_FROM_REG (HS_REG),
		0,
/*<<<*/	SCR_JUMPR ^ IFFALSE (MASK (0, HS_DONEMASK)),
		16,
	SCR_FROM_REG (SS_REG),
		0,
	SCR_JUMP ^ IFTRUE (DATA (S_CHECK_COND)),
		PADDRH(getcc2),
	/*
	**	And make the DSA register invalid.
	*/
/*>>>*/	SCR_LOAD_REG (dsa, 0xff), /* invalid */
		0,
}/*-------------------------< SIGNAL >----------------------*/,{
	/*
	**	if status = queue full,
	**	reinsert in startqueue and stall queue.
	*/
	SCR_FROM_REG (SS_REG),
		0,
	SCR_INT ^ IFTRUE (DATA (S_QUEUE_FULL)),
		SIR_STALL_QUEUE,
	/*
	**	if job completed ...
	*/
	SCR_FROM_REG (HS_REG),
		0,
	/*
	**	... signal completion to the host
	*/
	SCR_INT_FLY ^ IFFALSE (MASK (0, HS_DONEMASK)),
		0,
	/*
	**	Auf zu neuen Schandtaten!
	*/
	SCR_JUMP,
		PADDR(start),

}/*-------------------------< SAVE_DP >------------------*/,{
	/*
	**	SAVE_DP message:
	**	Copy TEMP register to SAVEP in header.
	*/
	SCR_COPY (4),
		RADDR (temp),
		NADDR (header.savep),
	SCR_JUMP,
		PADDR (clrack),
}/*-------------------------< RESTORE_DP >---------------*/,{
	/*
	**	RESTORE_DP message:
	**	Copy SAVEP in header to TEMP register.
	*/
	SCR_COPY (4),
		NADDR (header.savep),
		RADDR (temp),
	SCR_JUMP,
		PADDR (clrack),

}/*-------------------------< DISCONNECT >---------------*/,{
	/*
	**	If QUIRK_AUTOSAVE is set,
	**	do an "save pointer" operation.
	*/
	SCR_FROM_REG (QU_REG),
		0,
/*<<<*/	SCR_JUMPR ^ IFFALSE (MASK (QUIRK_AUTOSAVE, QUIRK_AUTOSAVE)),
		12,
	/*
	**	like SAVE_DP message:
	**	Copy TEMP register to SAVEP in header.
	*/
	SCR_COPY (4),
		RADDR (temp),
		NADDR (header.savep),
/*>>>*/	/*
	**	Check if temp==savep or temp==goalp:
	**	if not, log a missing save pointer message.
	**	In fact, it's a comparison mod 256.
	**
	**	Hmmm, I hadn't thought that I would be urged to
	**	write this kind of ugly self modifying code.
	**
	**	It's unbelievable, but the ncr53c8xx isn't able
	**	to subtract one register from another.
	*/
	SCR_FROM_REG (temp),
		0,
	/*
	**	You are not expected to understand this ..
	**
	**	CAUTION: only little endian architectures supported! XXX
	*/
	SCR_COPY_F (1),
		NADDR (header.savep),
		PADDR (disconnect0),
}/*-------------------------< DISCONNECT0 >--------------*/,{
/*<<<*/	SCR_JUMPR ^ IFTRUE (DATA (1)),
		20,
	/*
	**	neither this
	*/
	SCR_COPY_F (1),
		NADDR (header.goalp),
		PADDR (disconnect1),
}/*-------------------------< DISCONNECT1 >--------------*/,{
	SCR_INT ^ IFFALSE (DATA (1)),
		SIR_MISSING_SAVE,
/*>>>*/

	/*
	**	DISCONNECTing  ...
	**
	**	disable the "unexpected disconnect" feature,
	**	and remove the ACK signal.
	*/