TEXT	tas(SB), $0
	SYNC
	MOVW	R3, R4
	MOVW	$0xdeaddead,R5
tas1:
	DCBF	(R4)	/* fix for 603x bug */
	LWAR	(R4), R3
	CMP	R3, $0
	BNE	tas0
	DCBT	(R4)				/* fix 405 errata cpu_210 */
	STWCCC	R5, (R4)
	BNE	tas1
tas0:
	SYNC
	ISYNC
	RETURN