diff --git a/sys/arch/hp300/hp300/genassym.cf b/sys/arch/hp300/hp300/genassym.cf
index b2b088ec9cad..eaa3e71b6103 100644
--- a/sys/arch/hp300/hp300/genassym.cf
+++ b/sys/arch/hp300/hp300/genassym.cf
@@ -1,4 +1,4 @@
-#	$NetBSD: genassym.cf,v 1.24 2002/05/11 09:39:26 jdolecek Exp $
+#	$NetBSD: genassym.cf,v 1.25 2002/08/28 08:57:00 gmcgarry Exp $
 
 #
 # Copyright (c) 1982, 1990, 1993
@@ -57,6 +57,7 @@ endif
 
 include <machine/hp300spu.h>
 include <machine/cpu.h>
+include <machine/frame.h>
 include <machine/intr.h>
 include <machine/psl.h>
 include <machine/reg.h>
@@ -156,6 +157,7 @@ define	P_ADDR			offsetof(struct proc, p_addr)
 define	P_PRIORITY		offsetof(struct proc, p_priority)
 define	P_STAT			offsetof(struct proc, p_stat)
 define	P_WCHAN			offsetof(struct proc, p_wchan)
+define	P_NRAS			offsetof(struct proc, p_nras)
 define	P_MD_FLAGS		offsetof(struct proc, p_md.md_flags)
 define	P_MD_REGS		offsetof(struct proc, p_md.md_regs)
 define	SSLEEP			SSLEEP
@@ -219,6 +221,9 @@ define	SG_RW			SG_RW
 define	SG_FRAME		SG_FRAME
 define	SG_ISHIFT		SG_ISHIFT
 
+# frame fields
+define	TF_PC			offsetof(struct frame, f_pc)
+
 # pcb fields
 define	PCB_PS			offsetof(struct pcb, pcb_ps)
 define	PCB_USP			offsetof(struct pcb, pcb_usp)
diff --git a/sys/arch/hp300/hp300/locore.s b/sys/arch/hp300/hp300/locore.s
index a255ab9fa228..efa674bbc302 100644
--- a/sys/arch/hp300/hp300/locore.s
+++ b/sys/arch/hp300/hp300/locore.s
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.s,v 1.123 2002/06/27 08:45:25 gmcgarry Exp $	*/
+/*	$NetBSD: locore.s,v 1.124 2002/08/28 08:57:00 gmcgarry Exp $	*/
 
 /*
  * Copyright (c) 1994, 1995 Gordon W. Ross
@@ -1380,8 +1380,26 @@ Lswnofpsave:
 	pea	%a0@			| push proc
 	jbsr	_C_LABEL(pmap_activate)	| pmap_activate(p)
 	addql	#4,%sp
-	movl	_C_LABEL(curpcb),%a1	| restore p_addr
 
+/*
+ *  Check for restartable atomic sequences (RAS)
+ */
+	movl	_C_LABEL(curproc),%a0
+	tstl	%a0@(P_NRAS)
+	jeq	1f
+	movl	%a0@(P_MD_REGS),%a1
+	movl	%a1@(TF_PC),%sp@-
+	movl	%a0,%sp@-
+	jbsr	_C_LABEL(ras_lookup)
+	addql	#8,%sp
+	movql	#-1,%d0
+	cmpl	%a0,%d0
+	jeq	1f
+	movl	_C_LABEL(curproc),%a1
+	movl	%a1@(P_MD_REGS),%a1
+	movel	%a0,%a1@(TF_PC)
+1:
+	movl	_C_LABEL(curpcb),%a1	| restore p_addr
 	lea	_ASM_LABEL(tmpstk),%sp	| now goto a tmp stack for NMI
 
 	moveml	%a1@(PCB_REGS),#0xFCFC	| and registers
diff --git a/sys/arch/hp300/hp300/trap.c b/sys/arch/hp300/hp300/trap.c
index f1a2b7fd85d7..2cabde780a29 100644
--- a/sys/arch/hp300/hp300/trap.c
+++ b/sys/arch/hp300/hp300/trap.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: trap.c,v 1.95 2002/03/15 05:55:39 gmcgarry Exp $	*/
+/*	$NetBSD: trap.c,v 1.96 2002/08/28 08:57:01 gmcgarry Exp $	*/
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -43,7 +43,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.95 2002/03/15 05:55:39 gmcgarry Exp $");                                                  
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.96 2002/08/28 08:57:01 gmcgarry Exp $");                                                  
 
 #include "opt_ddb.h"
 #include "opt_execfmt.h"
@@ -59,6 +59,7 @@ __KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.95 2002/03/15 05:55:39 gmcgarry Exp $");
 #include <sys/acct.h>
 #include <sys/kernel.h>
 #include <sys/signalvar.h>
+#include <sys/ras.h>
 #include <sys/resourcevar.h>
 #include <sys/syscall.h>
 #include <sys/syslog.h>
@@ -502,6 +503,12 @@ trap(type, code, v, frame)
 		/* FALLTHROUGH */
 	case T_TRACE:		/* tracing a trap instruction */
 	case T_TRAP15|T_USER:	/* SUN user trace trap */
+		/*
+		 * Don't go stepping into a RAS.
+		 */
+		if ((p->p_nras != 0) &&
+		    (ras_lookup(p, (caddr_t)frame.f_pc) != (caddr_t)-1))
+			goto out;
 		frame.f_sr &= ~PSL_T;
 		i = SIGTRAP;
 		break;
diff --git a/sys/arch/hp300/include/types.h b/sys/arch/hp300/include/types.h
index d0175b0c62fe..0453eb2e7e9b 100644
--- a/sys/arch/hp300/include/types.h
+++ b/sys/arch/hp300/include/types.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: types.h,v 1.11 2002/02/28 03:17:33 simonb Exp $	*/
+/*	$NetBSD: types.h,v 1.12 2002/08/28 08:56:59 gmcgarry Exp $	*/
 
 #ifndef _MACHINE_TYPES_H_
 #define	_MACHINE_TYPES_H_
@@ -7,5 +7,6 @@
 
 #define	__HAVE_DEVICE_REGISTER
 #define	__HAVE_GENERIC_SOFT_INTERRUPTS
+#define __HAVE_RAS
 
 #endif