diff --git a/sys/arch/arm/ofw/openfirm.c b/sys/arch/arm/ofw/openfirm.c
index 4b29ff8202e4..a65411064e0a 100644
--- a/sys/arch/arm/ofw/openfirm.c
+++ b/sys/arch/arm/ofw/openfirm.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: openfirm.c,v 1.5 2005/12/11 12:16:51 christos Exp $	*/
+/*	$NetBSD: openfirm.c,v 1.6 2007/02/28 20:31:40 macallan Exp $	*/
 
 /*
  * Copyright 1997
@@ -65,7 +65,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: openfirm.c,v 1.5 2005/12/11 12:16:51 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: openfirm.c,v 1.6 2007/02/28 20:31:40 macallan Exp $");
 
 #include <sys/param.h>
 
@@ -237,6 +237,39 @@ OF_getprop(handle, prop, buf, buflen)
 	return args.size;
 }
 
+int
+OF_setprop(handle, prop, buf, buflen)
+	int handle;
+	const char *prop;
+	const void *buf;
+	int buflen;
+{
+	static struct {
+		const char *name;
+		int nargs;
+		int nreturns;
+		int phandle;
+		const char *prop;
+		const void *buf;
+		int buflen;
+		int size;
+	} args = {
+		"setprop",
+		4,
+		1,
+	};
+
+	args.phandle = handle;
+	args.prop = prop;
+	args.buf = buf;
+	args.buflen = buflen;
+
+
+	if (openfirmware(&args) == -1)
+		return -1;
+	return args.size;
+}
+
 int
 OF_getproplen(handle, prop)
 	int handle;
diff --git a/sys/arch/powerpc/powerpc/openfirm.c b/sys/arch/powerpc/powerpc/openfirm.c
index e4ca4b1a42f8..9038ac2224b5 100644
--- a/sys/arch/powerpc/powerpc/openfirm.c
+++ b/sys/arch/powerpc/powerpc/openfirm.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: openfirm.c,v 1.17 2006/01/22 22:53:56 ross Exp $	*/
+/*	$NetBSD: openfirm.c,v 1.18 2007/02/28 20:30:57 macallan Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: openfirm.c,v 1.17 2006/01/22 22:53:56 ross Exp $");
+__KERNEL_RCSID(0, "$NetBSD: openfirm.c,v 1.18 2007/02/28 20:30:57 macallan Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -195,6 +195,38 @@ OF_getprop(int handle, const char *prop, void *buf, int buflen)
 	return args.size;
 }
 
+int
+OF_setprop(int handle, const char *prop, const void *buf, int buflen)
+{
+	struct {
+		const char *name;
+		int nargs;
+		int nreturns;
+		int phandle;
+		const char *prop;
+		const void *buf;
+		int buflen;
+		int size;
+	} args = {
+		"setprop", 
+		4,
+		1
+	};
+	ofw_stack();
+
+	if (buflen > NBPG)
+		return -1;
+
+	ofbcopy(buf, OF_buf, buflen);
+	args.phandle = handle;
+	args.prop = prop;
+	args.buf = OF_buf;
+	args.buflen = buflen;
+	if (openfirmware(&args) == -1)
+		return -1;
+	return args.size;
+}
+
 int
 OF_nextprop(int handle, const char *prop, void *nextprop)
 {