--- cci/d/event/roprnd_evt.s	2019/07/28 12:24:19	1.1.1.1
+++ cci/d/event/roprnd_evt.s	2019/07/28 12:30:53	1.1.1.2
@@ -23,23 +23,21 @@
 	.globl	_roprnd_evt
 _roprnd_evt:
 	.word	0x1fff
-	mtpr	$31,$IPL
-	movab	(sp),_savvec0		/* Save current SP 		*/
+	mtpr	$31,$IPL		/* disable interrupts */
+	movab	(sp),_savvec0		/* Save current SP (ISP)	*/
 	mtpr	_savvec0,$ISP		/* Set ISP = current SP 	*/
+	mfpr	$KSP,_savvec9		/* Save kernal stack pointer */
+	mfpr	$USP,_savveca		/* Save user stack pointer */
 	movl	_scb+ROVEC,_savvec2	/* Save vector of Resr. oprd fault */
 	movab	ropflt1,_scb+ROVEC	/* Set new vector 		*/
 	movl	$-1,-(sp)		/* Push marker on stack		*/
 
-	movab	_pcb0,r1		/* Partially set PCBB		*/
-	mtpr	r1,$PCBB		/* Set PCBB to PCB_0		*/
-	movab	(sp),_pcb0		/* Set PCB_KSP = current SP	*/
-	movab	(sp),_pcb0+4		/* Set PCB_USP = current SP	*/
 
+	movl	_scb+PINSTVEC,_savvec3
 	movpsl	r1			/* If PSL_MODE != Kernel then	*/
 	bitl	$0x01000000,r1		/* change to Kernel mode by 	*/
 	beql	1f			/* executing a privilege inst.  */
-	movl	_scb+PINSTVEC,_savvec3	/* as HALT			*/
-	movab	tempvec,_scb+PINSTVEC
+	movab	tempvec,_scb+PINSTVEC	/* as HALT			*/
 	halt
 
 	.align	2
@@ -81,7 +79,7 @@ ropflt1:
 1:
 	cmpl	$1,r11		/* Is fault caused by REI or MTPR ?	*/
 	bneq	1f		/* Skip this part if come here from MTPR */
-	movl	(sp)+,r10	/* REI fault : get rid off PC,PSL on the */
+	movl	(sp)+,r10	/* REI fault : get rid of PC,PSL on the */
 	movl	(sp)+,r10	/* stack then check for marker 		*/
 
 1:
@@ -163,10 +161,11 @@ reit3:
 	jmp	*badrtn
 
 #
-#	REI with illegal PSL on the stack : PSL_IS on; Try to switch
+#	REI with illegal PSL on the stack : PSL_IS is off ; Try to switch
 #	to Interrupt stack by REI
 #
 1:				/* Current PSL_IS is OFF		*/
+	movl	$-1,-(sp)	/* push marker on stack (kernal stack)	*/
 	movab	reit4,r6	/* R6 = return address after exception	*/
 	movab	reit3a,r5	/* R5 = expected PC on stack 		*/
 	movl	r5,r3
@@ -224,10 +223,13 @@ reit6:
 	movl	_savvec2,_scb+ROVEC
 	pushl	$0			/* Push dummy PSL,PC on stack	*/
 	pushl	$0
+	mtpr	$31,$IPL		/* Reset IPL to HIGH		*/
 	svpctx				/* Switch to ISP		*/
 btisp:
-	mtpr	$31,$IPL		/* Reset IPL to HIGH		*/
 	movl	_savvec0,sp		/* Restore SP 			*/
+	mtpr	_savvec0,$ISP		/* Restore ISP 			*/
+	mtpr	_savvec9,$KSP		/* Restore KSP 			*/
+	mtpr	_savveca,$USP		/* Restore USP 			*/
 	ret
 #
 #