Move Open Firmware device root on PowerPC, ARM, and MIPS systems to

a sub-node of nexus (ofwbus) rather than direct attach under nexus. This
fixes FDT on x86 and will make coexistence with ACPI on ARM systems easier.
SPARC is unchanged.

Reviewed by:	imp, ian

31 files changed, 167 insertions, 280 deletions

diff --git a/sys/arm/arm/nexus.c b/sys/arm/arm/nexus.c
index ec2c18f..fe1261f 100644
--- a/sys/arm/arm/nexus.c
+++ b/sys/arm/arm/nexus.c
@@ -63,11 +63,11 @@ __FBSDID("$FreeBSD$");
 #include "opt_platform.h"
 
 #ifdef FDT
-#include <dev/ofw/ofw_nexus.h>
 #include <dev/fdt/fdt_common.h>
 #include <machine/fdt.h>
 #include "ofw_bus_if.h"
-#else
+#endif
+
 static MALLOC_DEFINE(M_NEXUSDEV, "nexusdev", "Nexus device");
 
 struct nexus_device {
@@ -84,7 +84,6 @@ static	int nexus_print_child(device_t, device_t);
 static	device_t nexus_add_child(device_t, u_int, const char *, int);
 static	struct resource *nexus_alloc_resource(device_t, device_t, int, int *,
     u_long, u_long, u_long, u_int);
-#endif
 static	int nexus_activate_resource(device_t, device_t, int, int,
     struct resource *);
 static int nexus_config_intr(device_t dev, int irq, enum intr_trigger trig,
@@ -102,7 +101,6 @@ static int nexus_ofw_map_intr(device_t dev, device_t child, phandle_t iparent,
 #endif
 
 static device_method_t nexus_methods[] = {
-#ifndef FDT
 	/* Device interface */
 	DEVMETHOD(device_probe,		nexus_probe),
 	DEVMETHOD(device_attach,	nexus_attach),
@@ -110,7 +108,6 @@ static device_method_t nexus_methods[] = {
 	DEVMETHOD(bus_print_child,	nexus_print_child),
 	DEVMETHOD(bus_add_child,	nexus_add_child),
 	DEVMETHOD(bus_alloc_resource,	nexus_alloc_resource),
-#endif
 	DEVMETHOD(bus_activate_resource,	nexus_activate_resource),
 	DEVMETHOD(bus_config_intr,	nexus_config_intr),
 	DEVMETHOD(bus_deactivate_resource,	nexus_deactivate_resource),
@@ -123,19 +120,13 @@ static device_method_t nexus_methods[] = {
 };
 
 static devclass_t nexus_devclass;
-#ifndef FDT
 static driver_t nexus_driver = {
 	"nexus",
 	nexus_methods,
 	1			/* no softc */
 };
-#else
-DEFINE_CLASS_1(nexus, nexus_driver, nexus_methods,
-    sizeof(struct ofw_nexus_softc), ofw_nexus_driver);
-#endif
 DRIVER_MODULE(nexus, root, nexus_driver, nexus_devclass, 0, 0);
 
-#ifndef FDT
 static int
 nexus_probe(device_t dev)
 {
@@ -235,7 +226,6 @@ nexus_alloc_resource(device_t bus, device_t child, int type, int *rid,
 
 	return (rv);
 }
-#endif
 
 static int
 nexus_config_intr(device_t dev, int irq, enum intr_trigger trig,
diff --git a/sys/arm/broadcom/bcm2835/bcm2835_fb.c b/sys/arm/broadcom/bcm2835/bcm2835_fb.c
index 5dd5f99..88156ed 100644
--- a/sys/arm/broadcom/bcm2835/bcm2835_fb.c
+++ b/sys/arm/broadcom/bcm2835/bcm2835_fb.c
@@ -361,7 +361,7 @@ static driver_t bcm_fb_driver = {
 	sizeof(struct bcmsc_softc),
 };
 
-DRIVER_MODULE(bcm2835fb, nexus, bcm_fb_driver, bcm_fb_devclass, 0, 0);
+DRIVER_MODULE(bcm2835fb, ofwbus, bcm_fb_driver, bcm_fb_devclass, 0, 0);
 
 /*
  * Video driver routines and glue.
diff --git a/sys/arm/broadcom/bcm2835/bcm2835_fbd.c b/sys/arm/broadcom/bcm2835/bcm2835_fbd.c
index 2c69b9a..cf7cecd 100644
--- a/sys/arm/broadcom/bcm2835/bcm2835_fbd.c
+++ b/sys/arm/broadcom/bcm2835/bcm2835_fbd.c
@@ -315,4 +315,4 @@ static driver_t bcm_fb_driver = {
 	sizeof(struct bcmsc_softc),
 };
 
-DRIVER_MODULE(bcm2835fb, nexus, bcm_fb_driver, bcm_fb_devclass, 0, 0);
+DRIVER_MODULE(bcm2835fb, ofwbus, bcm_fb_driver, bcm_fb_devclass, 0, 0);
diff --git a/sys/arm/freescale/imx/tzic.c b/sys/arm/freescale/imx/tzic.c
index 39548dc..0f3cf5c 100644
--- a/sys/arm/freescale/imx/tzic.c
+++ b/sys/arm/freescale/imx/tzic.c
@@ -146,9 +146,9 @@ static devclass_t tzic_devclass;
 
 /*
  * Memory space of controller located outside of device range, so let him to
- * attach not only to simplebus, but nexus also.
+ * attach not only to simplebus, but ofwbus also.
  */
-EARLY_DRIVER_MODULE(tzic, nexus, tzic_driver, tzic_devclass, 0, 0,
+EARLY_DRIVER_MODULE(tzic, ofwbus, tzic_driver, tzic_devclass, 0, 0,
     BUS_PASS_INTERRUPT);
 EARLY_DRIVER_MODULE(tzic, simplebus, tzic_driver, tzic_devclass, 0, 0,
     BUS_PASS_INTERRUPT);
diff --git a/sys/arm/mv/mv_localbus.c b/sys/arm/mv/mv_localbus.c
index 7172096..0882ad4 100644
--- a/sys/arm/mv/mv_localbus.c
+++ b/sys/arm/mv/mv_localbus.c
@@ -156,7 +156,7 @@ static struct localbus_bank localbus_banks[MV_LOCALBUS_MAX_BANKS];
 
 devclass_t localbus_devclass;
 
-DRIVER_MODULE(localbus, nexus, localbus_driver, localbus_devclass, 0, 0);
+DRIVER_MODULE(localbus, ofwbus, localbus_driver, localbus_devclass, 0, 0);
 
 static int
 fdt_localbus_reg_decode(phandle_t node, struct localbus_softc *sc,
diff --git a/sys/arm/mv/mv_pci.c b/sys/arm/mv/mv_pci.c
index 690ebb4..be4ccc9 100644
--- a/sys/arm/mv/mv_pci.c
+++ b/sys/arm/mv/mv_pci.c
@@ -398,7 +398,7 @@ static driver_t mv_pcib_driver = {
 
 devclass_t pcib_devclass;
 
-DRIVER_MODULE(pcib, nexus, mv_pcib_driver, pcib_devclass, 0, 0);
+DRIVER_MODULE(pcib, ofwbus, mv_pcib_driver, pcib_devclass, 0, 0);
 
 static struct mtx pcicfg_mtx;
 
diff --git a/sys/conf/files b/sys/conf/files
index dea5920..dba13a7 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1370,7 +1370,6 @@ dev/fdt/fdt_common.c		optional fdt
 dev/fdt/fdt_slicer.c		optional fdt cfi | fdt nand
 dev/fdt/fdt_static_dtb.S	optional fdt fdt_dtb_static \
 	dependency	"$S/boot/fdt/dts/${FDT_DTS_FILE}"
-dev/fdt/fdtbus.c		optional fdtbus
 dev/fdt/simplebus.c		optional fdt
 dev/fe/if_fe.c			optional fe
 dev/fe/if_fe_pccard.c		optional fe pccard
@@ -1886,7 +1885,7 @@ dev/ofw/ofw_bus_subr.c		optional fdt
 dev/ofw/ofw_fdt.c		optional fdt
 dev/ofw/ofw_if.m		optional fdt
 dev/ofw/ofw_iicbus.c		optional fdt iicbus
-dev/ofw/ofw_nexus.c		optional fdt
+dev/ofw/ofwbus.c		optional fdt
 dev/ofw/openfirm.c		optional fdt
 dev/ofw/openfirmio.c		optional fdt
 dev/patm/if_patm.c		optional patm pci
diff --git a/sys/conf/files.powerpc b/sys/conf/files.powerpc
index 63b70c4..0e9d1c3 100644
--- a/sys/conf/files.powerpc
+++ b/sys/conf/files.powerpc
@@ -48,7 +48,7 @@ dev/ofw/ofw_bus_subr.c		optional	aim
 dev/ofw/ofw_console.c		optional	aim
 dev/ofw/ofw_disk.c		optional	ofwd aim
 dev/ofw/ofw_iicbus.c		optional	iicbus aim
-dev/ofw/ofw_nexus.c		optional	aim | fdt
+dev/ofw/ofwbus.c		optional	aim | fdt
 dev/ofw/ofw_standard.c		optional	aim powerpc
 dev/powermac_nvram/powermac_nvram.c optional	powermac_nvram powermac
 dev/quicc/quicc_bfe_fdt.c	optional	quicc mpc85xx
diff --git a/sys/dev/fdt/fdtbus.c b/sys/dev/fdt/fdtbus.c
deleted file mode 100644
index a0ebec8..0000000
--- a/sys/dev/fdt/fdtbus.c
+++ /dev/null
@@ -1,91 +0,0 @@
-/*-
- * Copyright (c) 2009-2010 The FreeBSD Foundation
- * All rights reserved.
- *
- * This software was developed by Semihalf under sponsorship from
- * the FreeBSD Foundation.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/ktr.h>
-#include <sys/kernel.h>
-#include <sys/module.h>
-#include <sys/bus.h>
-#include <sys/rman.h>
-#include <sys/malloc.h>
-
-#include <dev/ofw/openfirm.h>
-#include <dev/ofw/ofw_nexus.h>
-
-#include "ofw_bus_if.h"
-
-/*
- * Prototypes.
- */
-static void fdtbus_identify(driver_t *, device_t);
-static int fdtbus_probe(device_t);
-
-/*
- * Bus interface definition.
- */
-static device_method_t fdtbus_methods[] = {
-	/* Device interface */
-	DEVMETHOD(device_identify,	fdtbus_identify),
-	DEVMETHOD(device_probe,		fdtbus_probe),
-
-	/* Bus interface */
-	DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
-	DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
-	DEVMETHOD(bus_config_intr,	bus_generic_config_intr),
-	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
-	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
-
-	DEVMETHOD_END
-};
-
-devclass_t fdtbus_devclass;
-DEFINE_CLASS_1(fdtbus, fdtbus_driver, fdtbus_methods,
-    sizeof(struct ofw_nexus_softc), ofw_nexus_driver);
-DRIVER_MODULE(fdtbus, nexus, fdtbus_driver, fdtbus_devclass, 0, 0);
-
-static void
-fdtbus_identify(driver_t *driver, device_t parent)
-{
-
-	if (device_find_child(parent, "fdtbus", -1) == NULL)
-		BUS_ADD_CHILD(parent, 0, "fdtbus", -1);
-}
-
-static int
-fdtbus_probe(device_t dev)
-{
-
-	device_set_desc(dev, "Flattened Device Tree");
-	return (BUS_PROBE_NOWILDCARD);
-}
-
diff --git a/sys/dev/fdt/simplebus.c b/sys/dev/fdt/simplebus.c
index ee968ae..d36cba4 100644
--- a/sys/dev/fdt/simplebus.c
+++ b/sys/dev/fdt/simplebus.c
@@ -121,7 +121,7 @@ static driver_t simplebus_driver = {
 	sizeof(struct simplebus_softc)
 };
 static devclass_t simplebus_devclass;
-DRIVER_MODULE(simplebus, nexus, simplebus_driver, simplebus_devclass, 0, 0);
+DRIVER_MODULE(simplebus, ofwbus, simplebus_driver, simplebus_devclass, 0, 0);
 DRIVER_MODULE(simplebus, simplebus, simplebus_driver, simplebus_devclass, 0, 0);
 
 static int
diff --git a/sys/dev/ofw/ofw_nexus.h b/sys/dev/ofw/ofw_nexus.h
deleted file mode 100644
index e67b4a3..0000000
--- a/sys/dev/ofw/ofw_nexus.h
+++ /dev/null
@@ -1,40 +0,0 @@
-/*-
- * Copyright (c) 2010 Marius Strobl <marius@FreeBSD.org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * $FreeBSD$
- */
-
-#ifndef _OFW_NEXUS_H_
-#define	_OFW_NEXUS_H_
-
-struct ofw_nexus_softc {
-	uint32_t	acells, scells;
-	struct rman	sc_intr_rman;
-	struct rman	sc_mem_rman;
-};
-
-DECLARE_CLASS(ofw_nexus_driver);
-
-#endif /* _OFW_NEXUS_H_ */
diff --git a/sys/dev/ofw/ofw_nexus.c b/sys/dev/ofw/ofwbus.c
index b3c5e03..d06917d 100644
--- a/sys/dev/ofw/ofw_nexus.c
+++ b/sys/dev/ofw/ofwbus.c
@@ -49,69 +49,78 @@ __FBSDID("$FreeBSD$");
 
 #include <dev/ofw/ofw_bus.h>
 #include <dev/ofw/ofw_bus_subr.h>
-#include <dev/ofw/ofw_nexus.h>
 #include <dev/ofw/openfirm.h>
 
 #include <machine/bus.h>
 #include <machine/resource.h>
 
 /*
- * The nexus (which is a pseudo-bus actually) iterates over the nodes that
+ * The ofwbus (which is a pseudo-bus actually) iterates over the nodes that
  * hang from the Open Firmware root node and adds them as devices to this bus
  * (except some special nodes which are excluded) so that drivers can be
  * attached to them.
  *
- * Additionally, interrupt setup/teardown and some resource management are
- * done at this level.
- *
  */
 
-struct nexus_devinfo {
+struct ofwbus_devinfo {
 	struct ofw_bus_devinfo	ndi_obdinfo;
 	struct resource_list	ndi_rl;
 };
 
-static device_probe_t nexus_probe;
-static device_attach_t nexus_attach;
-static bus_print_child_t nexus_print_child;
-static bus_add_child_t nexus_add_child;
-static bus_probe_nomatch_t nexus_probe_nomatch;
-static bus_alloc_resource_t nexus_alloc_resource;
-static bus_adjust_resource_t nexus_adjust_resource;
-static bus_release_resource_t nexus_release_resource;
-static bus_get_resource_list_t nexus_get_resource_list;
-static ofw_bus_get_devinfo_t nexus_get_devinfo;
-
-static int nexus_inlist(const char *, const char *const *);
-static struct nexus_devinfo * nexus_setup_dinfo(device_t, phandle_t);
-static void nexus_destroy_dinfo(struct nexus_devinfo *);
-static int nexus_print_res(struct nexus_devinfo *);
-
-static device_method_t nexus_methods[] = {
+struct ofwbus_softc {
+	uint32_t	acells, scells;
+	struct rman	sc_intr_rman;
+	struct rman	sc_mem_rman;
+};
+
+static device_identify_t ofwbus_identify;
+static device_probe_t ofwbus_probe;
+static device_attach_t ofwbus_attach;
+static bus_print_child_t ofwbus_print_child;
+static bus_add_child_t ofwbus_add_child;
+static bus_probe_nomatch_t ofwbus_probe_nomatch;
+static bus_alloc_resource_t ofwbus_alloc_resource;
+static bus_adjust_resource_t ofwbus_adjust_resource;
+static bus_release_resource_t ofwbus_release_resource;
+static bus_get_resource_list_t ofwbus_get_resource_list;
+static ofw_bus_get_devinfo_t ofwbus_get_devinfo;
+
+static int ofwbus_inlist(const char *, const char *const *);
+static struct ofwbus_devinfo * ofwbus_setup_dinfo(device_t, phandle_t);
+static void ofwbus_destroy_dinfo(struct ofwbus_devinfo *);
+static int ofwbus_print_res(struct ofwbus_devinfo *);
+
+static device_method_t ofwbus_methods[] = {
 	/* Device interface */
-	DEVMETHOD(device_probe,		nexus_probe),
-	DEVMETHOD(device_attach,	nexus_attach),
+	DEVMETHOD(device_identify,	ofwbus_identify),
+	DEVMETHOD(device_probe,		ofwbus_probe),
+	DEVMETHOD(device_attach,	ofwbus_attach),
 	DEVMETHOD(device_detach,	bus_generic_detach),
 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
 	DEVMETHOD(device_suspend,	bus_generic_suspend),
 	DEVMETHOD(device_resume,	bus_generic_resume),
 
 	/* Bus interface */
-	DEVMETHOD(bus_print_child,	nexus_print_child),
-	DEVMETHOD(bus_probe_nomatch,	nexus_probe_nomatch),
+	DEVMETHOD(bus_print_child,	ofwbus_print_child),
+	DEVMETHOD(bus_probe_nomatch,	ofwbus_probe_nomatch),
 	DEVMETHOD(bus_read_ivar,	bus_generic_read_ivar),
 	DEVMETHOD(bus_write_ivar,	bus_generic_write_ivar),
-	DEVMETHOD(bus_add_child,	nexus_add_child),
+	DEVMETHOD(bus_add_child,	ofwbus_add_child),
 	DEVMETHOD(bus_child_pnpinfo_str, ofw_bus_gen_child_pnpinfo_str),
-	DEVMETHOD(bus_alloc_resource,	nexus_alloc_resource),
-	DEVMETHOD(bus_adjust_resource,	nexus_adjust_resource),
-	DEVMETHOD(bus_release_resource,	nexus_release_resource),
+	DEVMETHOD(bus_alloc_resource,	ofwbus_alloc_resource),
+	DEVMETHOD(bus_adjust_resource,	ofwbus_adjust_resource),
+	DEVMETHOD(bus_release_resource,	ofwbus_release_resource),
 	DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
 	DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
-	DEVMETHOD(bus_get_resource_list, nexus_get_resource_list),
+	DEVMETHOD(bus_get_resource_list, ofwbus_get_resource_list),
+	DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
+	DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
+	DEVMETHOD(bus_config_intr,	bus_generic_config_intr),
+	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
+	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
 
 	/* ofw_bus interface */
-	DEVMETHOD(ofw_bus_get_devinfo,	nexus_get_devinfo),
+	DEVMETHOD(ofw_bus_get_devinfo,	ofwbus_get_devinfo),
 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
@@ -121,11 +130,16 @@ static device_method_t nexus_methods[] = {
 	DEVMETHOD_END
 };
 
-DEFINE_CLASS_0(ofw_nexus, ofw_nexus_driver, nexus_methods,
-    sizeof(struct ofw_nexus_softc));
-MODULE_VERSION(ofw_nexus, 1);
+static driver_t ofwbus_driver = {
+	"ofwbus",
+	ofwbus_methods,
+	sizeof(struct ofwbus_softc)
+};
+static devclass_t ofwbus_devclass;
+DRIVER_MODULE(ofwbus, nexus, ofwbus_driver, ofwbus_devclass, 0, 0);
+MODULE_VERSION(ofwbus, 1);
 
-static const char *const nexus_excl_name[] = {
+static const char *const ofwbus_excl_name[] = {
 	"FJSV,system",
 	"aliases",
 	"associations",
@@ -145,14 +159,14 @@ static const char *const nexus_excl_name[] = {
 	NULL
 };
 
-static const char *const nexus_excl_type[] = {
+static const char *const ofwbus_excl_type[] = {
 	"core",
 	"cpu",
 	NULL
 };
 
 static int
-nexus_inlist(const char *name, const char *const *list)
+ofwbus_inlist(const char *name, const char *const *list)
 {
 	int i;
 
@@ -164,24 +178,35 @@ nexus_inlist(const char *name, const char *const *list)
 	return (0);
 }
 
-#define	NEXUS_EXCLUDED(name, type)					\
-	(nexus_inlist((name), nexus_excl_name) ||			\
-	((type) != NULL && nexus_inlist((type), nexus_excl_type)))
+#define	OFWBUS_EXCLUDED(name, type)					\
+	(ofwbus_inlist((name), ofwbus_excl_name) ||			\
+	((type) != NULL && ofwbus_inlist((type), ofwbus_excl_type)))
+
+static void
+ofwbus_identify(driver_t *driver, device_t parent)
+{
+
+	/* Check if Open Firmware has been instantiated */
+	if (OF_peer(0) == -1)
+		return;
+        
+	if (device_find_child(parent, "ofwbus", -1) == NULL)
+		BUS_ADD_CHILD(parent, 0, "ofwbus", -1);
+}
 
 static int
-nexus_probe(device_t dev)
+ofwbus_probe(device_t dev)
 {
 
-	/* Nexus does always match. */
-	device_set_desc(dev, "Open Firmware Nexus device");
-	return (0);
+	device_set_desc(dev, "Open Firmware Device Tree");
+	return (BUS_PROBE_NOWILDCARD);
 }
 
 static int
-nexus_attach(device_t dev)
+ofwbus_attach(device_t dev)
 {
-	struct nexus_devinfo *ndi;
-	struct ofw_nexus_softc *sc;
+	struct ofwbus_devinfo *ndi;
+	struct ofwbus_softc *sc;
 	device_t cdev;
 	phandle_t node;
 
@@ -189,6 +214,12 @@ nexus_attach(device_t dev)
 
 	node = OF_peer(0);
 
+	/*
+	 * If no Open Firmware, bail early
+	 */
+	if (node == -1)
+		return (ENXIO);
+
 	sc->sc_intr_rman.rm_type = RMAN_ARRAY;
 	sc->sc_intr_rman.rm_descr = "Interrupts";
 	sc->sc_mem_rman.rm_type = RMAN_ARRAY;
@@ -205,12 +236,6 @@ nexus_attach(device_t dev)
 	bus_generic_probe(dev);
 
 	/*
-	 * If no Open Firmware, bail early
-	 */
-	if (node == -1)
-		return (bus_generic_attach(dev));
-
-	/*
 	 * Some important numbers
 	 */
 	sc->acells = 2;
@@ -222,13 +247,13 @@ nexus_attach(device_t dev)
 	 * Now walk the OFW tree and attach top-level devices.
 	 */
 	for (node = OF_child(node); node > 0; node = OF_peer(node)) {
-		if ((ndi = nexus_setup_dinfo(dev, node)) == NULL)
+		if ((ndi = ofwbus_setup_dinfo(dev, node)) == NULL)
 			continue;
 		cdev = device_add_child(dev, NULL, -1);
 		if (cdev == NULL) {
 			device_printf(dev, "<%s>: device_add_child failed\n",
 			    ndi->ndi_obdinfo.obd_name);
-			nexus_destroy_dinfo(ndi);
+			ofwbus_destroy_dinfo(ndi);
 			continue;
 		}
 		device_set_ivars(cdev, ndi);
@@ -237,10 +262,10 @@ nexus_attach(device_t dev)
 }
 
 static device_t
-nexus_add_child(device_t dev, u_int order, const char *name, int unit)
+ofwbus_add_child(device_t dev, u_int order, const char *name, int unit)
 {
 	device_t cdev;
-	struct nexus_devinfo *ndi;
+	struct ofwbus_devinfo *ndi;
 
 	cdev = device_add_child_ordered(dev, order, name, unit);
 	if (cdev == NULL)
@@ -255,18 +280,18 @@ nexus_add_child(device_t dev, u_int order, const char *name, int unit)
 }
 
 static int
-nexus_print_child(device_t bus, device_t child)
+ofwbus_print_child(device_t bus, device_t child)
 {
 	int rv;
 
 	rv = bus_print_child_header(bus, child);
-	rv += nexus_print_res(device_get_ivars(child));
+	rv += ofwbus_print_res(device_get_ivars(child));
 	rv += bus_print_child_footer(bus, child);
 	return (rv);
 }
 
 static void
-nexus_probe_nomatch(device_t bus, device_t child)
+ofwbus_probe_nomatch(device_t bus, device_t child)
 {
 	const char *name, *type;
 
@@ -278,16 +303,16 @@ nexus_probe_nomatch(device_t bus, device_t child)
 
 	device_printf(bus, "<%s>",
 	    name != NULL ? name : "unknown");
-	nexus_print_res(device_get_ivars(child));
+	ofwbus_print_res(device_get_ivars(child));
 	printf(" type %s (no driver attached)\n",
 	    type != NULL ? type : "unknown");
 }
 
 static struct resource *
-nexus_alloc_resource(device_t bus, device_t child, int type, int *rid,
+ofwbus_alloc_resource(device_t bus, device_t child, int type, int *rid,
     u_long start, u_long end, u_long count, u_int flags)
 {
-	struct ofw_nexus_softc *sc;
+	struct ofwbus_softc *sc;
 	struct rman *rm;
 	struct resource *rv;
 	struct resource_list_entry *rle;
@@ -344,17 +369,17 @@ nexus_alloc_resource(device_t bus, device_t child, int type, int *rid,
 }
 
 static int
-nexus_adjust_resource(device_t bus, device_t child __unused, int type,
+ofwbus_adjust_resource(device_t bus, device_t child __unused, int type,
     struct resource *r, u_long start, u_long end)
 {
-	struct ofw_nexus_softc *sc;
+	struct ofwbus_softc *sc;
 	struct rman *rm;
-	device_t nexus;
+	device_t ofwbus;
 
-	nexus = bus;
-	while (strcmp(device_get_name(device_get_parent(nexus)), "root") != 0)
-		nexus = device_get_parent(nexus);
-	sc = device_get_softc(nexus);
+	ofwbus = bus;
+	while (strcmp(device_get_name(device_get_parent(ofwbus)), "root") != 0)
+		ofwbus = device_get_parent(ofwbus);
+	sc = device_get_softc(ofwbus);
 	switch (type) {
 	case SYS_RES_IRQ:
 		rm = &sc->sc_intr_rman;
@@ -373,7 +398,7 @@ nexus_adjust_resource(device_t bus, device_t child __unused, int type,
 }
 
 static int
-nexus_release_resource(device_t bus __unused, device_t child, int type,
+ofwbus_release_resource(device_t bus __unused, device_t child, int type,
     int rid, struct resource *r)
 {
 	int error;
@@ -387,28 +412,28 @@ nexus_release_resource(device_t bus __unused, device_t child, int type,
 }
 
 static struct resource_list *
-nexus_get_resource_list(device_t bus __unused, device_t child)
+ofwbus_get_resource_list(device_t bus __unused, device_t child)
 {
-	struct nexus_devinfo *ndi;
+	struct ofwbus_devinfo *ndi;
 
 	ndi = device_get_ivars(child);
 	return (&ndi->ndi_rl);
 }
 
 static const struct ofw_bus_devinfo *
-nexus_get_devinfo(device_t bus __unused, device_t child)
+ofwbus_get_devinfo(device_t bus __unused, device_t child)
 {
-	struct nexus_devinfo *ndi;
+	struct ofwbus_devinfo *ndi;
 
 	ndi = device_get_ivars(child);
 	return (&ndi->ndi_obdinfo);
 }
 
-static struct nexus_devinfo *
-nexus_setup_dinfo(device_t dev, phandle_t node)
+static struct ofwbus_devinfo *
+ofwbus_setup_dinfo(device_t dev, phandle_t node)
 {
-	struct ofw_nexus_softc *sc;
-	struct nexus_devinfo *ndi;
+	struct ofwbus_softc *sc;
+	struct ofwbus_devinfo *ndi;
 	uint32_t *reg, *intr, icells;
 	uint64_t phys, size;
 	phandle_t iparent;
@@ -423,7 +448,7 @@ nexus_setup_dinfo(device_t dev, phandle_t node)
 		free(ndi, M_DEVBUF);
 		return (NULL);
 	}
-	if (NEXUS_EXCLUDED(ndi->ndi_obdinfo.obd_name,
+	if (OFWBUS_EXCLUDED(ndi->ndi_obdinfo.obd_name,
 	    ndi->ndi_obdinfo.obd_type)) {
 		ofw_bus_gen_destroy_devinfo(&ndi->ndi_obdinfo);
 		free(ndi, M_DEVBUF);
@@ -479,7 +504,7 @@ nexus_setup_dinfo(device_t dev, phandle_t node)
 }
 
 static void
-nexus_destroy_dinfo(struct nexus_devinfo *ndi)
+ofwbus_destroy_dinfo(struct ofwbus_devinfo *ndi)
 {
 
 	resource_list_free(&ndi->ndi_rl);
@@ -488,7 +513,7 @@ nexus_destroy_dinfo(struct nexus_devinfo *ndi)
 }
 
 static int
-nexus_print_res(struct nexus_devinfo *ndi)
+ofwbus_print_res(struct ofwbus_devinfo *ndi)
 {
 	int rv;
 
diff --git a/sys/dev/powermac_nvram/powermac_nvram.c b/sys/dev/powermac_nvram/powermac_nvram.c
index 56dc929..53650e9 100644
--- a/sys/dev/powermac_nvram/powermac_nvram.c
+++ b/sys/dev/powermac_nvram/powermac_nvram.c
@@ -84,7 +84,7 @@ static driver_t	powermac_nvram_driver = {
 
 static devclass_t powermac_nvram_devclass;
 
-DRIVER_MODULE(powermac_nvram, nexus, powermac_nvram_driver, powermac_nvram_devclass, 0, 0);
+DRIVER_MODULE(powermac_nvram, ofwbus, powermac_nvram_driver, powermac_nvram_devclass, 0, 0);
 
 /*
  * Cdev methods.
diff --git a/sys/mips/beri/beri_simplebus.c b/sys/mips/beri/beri_simplebus.c
index 55b3149..934a395 100644
--- a/sys/mips/beri/beri_simplebus.c
+++ b/sys/mips/beri/beri_simplebus.c
@@ -136,7 +136,7 @@ static driver_t simplebus_driver = {
 
 devclass_t simplebus_devclass;
 
-DRIVER_MODULE(simplebus, nexus, simplebus_driver, simplebus_devclass, 0, 0);
+DRIVER_MODULE(simplebus, ofwbus, simplebus_driver, simplebus_devclass, 0, 0);
 DRIVER_MODULE(simplebus, simplebus, simplebus_driver, simplebus_devclass, 0,
     0);
 
diff --git a/sys/mips/mips/nexus.c b/sys/mips/mips/nexus.c
index ecf315d..06c0317 100644
--- a/sys/mips/mips/nexus.c
+++ b/sys/mips/mips/nexus.c
@@ -60,10 +60,6 @@ __FBSDID("$FreeBSD$");
 
 #include "opt_platform.h"
 
-#ifdef FDT
-#include <dev/ofw/ofw_nexus.h>
-#endif
-
 #undef NEXUS_DEBUG
 #ifdef NEXUS_DEBUG
 #define dprintf printf
@@ -73,7 +69,6 @@ __FBSDID("$FreeBSD$");
 
 #define NUM_MIPS_IRQS	6
 
-#ifndef FDT
 static MALLOC_DEFINE(M_NEXUSDEV, "nexusdev", "Nexus device");
 
 struct nexus_device {
@@ -102,7 +97,6 @@ static int	nexus_release_resource(device_t, device_t, int, int,
 		    struct resource *);
 static int	nexus_set_resource(device_t, device_t, int, int, u_long,
 		    u_long);
-#endif
 static int	nexus_activate_resource(device_t, device_t, int, int,
 		    struct resource *);
 static int	nexus_deactivate_resource(device_t, device_t, int, int,
@@ -115,7 +109,6 @@ static int	nexus_teardown_intr(device_t, device_t, struct resource *,
 		    void *);
 
 static device_method_t nexus_methods[] = {
-#ifndef FDT
 	/* Device interface */
 	DEVMETHOD(device_probe,		nexus_probe),
 	DEVMETHOD(device_attach,	nexus_attach),
@@ -129,7 +122,6 @@ static device_method_t nexus_methods[] = {
 	DEVMETHOD(bus_print_child,	nexus_print_child),
 	DEVMETHOD(bus_release_resource,	nexus_release_resource),
 	DEVMETHOD(bus_set_resource,	nexus_set_resource),
-#endif
 	DEVMETHOD(bus_setup_intr,	nexus_setup_intr),
 	DEVMETHOD(bus_teardown_intr,	nexus_teardown_intr),
 	DEVMETHOD(bus_activate_resource,nexus_activate_resource),
@@ -139,19 +131,13 @@ static device_method_t nexus_methods[] = {
 	{ 0, 0 }
 };
 
-#ifndef FDT
 static driver_t nexus_driver = {
 	"nexus",
 	nexus_methods,
 	1			/* no softc */
 };
-#else
-DEFINE_CLASS_1(nexus, nexus_driver, nexus_methods,
-    sizeof(struct ofw_nexus_softc), ofw_nexus_driver);
-#endif
 static devclass_t nexus_devclass;
 
-#ifndef FDT
 static int
 nexus_probe(device_t dev)
 {
@@ -387,7 +373,6 @@ nexus_release_resource(device_t bus, device_t child, int type, int rid,
 
 	return (rman_release_resource(r));
 }
-#endif
 
 static int
 nexus_activate_resource(device_t bus, device_t child, int type, int rid,
diff --git a/sys/powerpc/mambo/mambo.c b/sys/powerpc/mambo/mambo.c
index aa1b9a4..2c54476 100644
--- a/sys/powerpc/mambo/mambo.c
+++ b/sys/powerpc/mambo/mambo.c
@@ -75,7 +75,7 @@ static driver_t mambobus_driver = {
 
 static devclass_t mambobus_devclass;
 
-DRIVER_MODULE(mambo, nexus, mambobus_driver, mambobus_devclass, 0, 0);
+DRIVER_MODULE(mambo, ofwbus, mambobus_driver, mambobus_devclass, 0, 0);
 
 static int
 mambobus_probe(device_t dev)
diff --git a/sys/powerpc/mpc85xx/lbc.c b/sys/powerpc/mpc85xx/lbc.c
index 5c27ca4..62b56c3 100644
--- a/sys/powerpc/mpc85xx/lbc.c
+++ b/sys/powerpc/mpc85xx/lbc.c
@@ -113,7 +113,7 @@ static driver_t lbc_driver = {
 
 devclass_t lbc_devclass;
 
-DRIVER_MODULE(lbc, nexus, lbc_driver, lbc_devclass, 0, 0);
+DRIVER_MODULE(lbc, ofwbus, lbc_driver, lbc_devclass, 0, 0);
 
 /*
  * Calculate address mask used by OR(n) registers. Use memory region size to
diff --git a/sys/powerpc/mpc85xx/pci_mpc85xx.c b/sys/powerpc/mpc85xx/pci_mpc85xx.c
index 0699b22..f1b958f 100644
--- a/sys/powerpc/mpc85xx/pci_mpc85xx.c
+++ b/sys/powerpc/mpc85xx/pci_mpc85xx.c
@@ -170,7 +170,7 @@ static devclass_t fsl_pcib_devclass;
 
 DEFINE_CLASS_1(pcib, fsl_pcib_driver, fsl_pcib_methods,
     sizeof(struct fsl_pcib_softc), ofw_pci_driver);
-DRIVER_MODULE(pcib, nexus, fsl_pcib_driver, fsl_pcib_devclass, 0, 0);
+DRIVER_MODULE(pcib, ofwbus, fsl_pcib_driver, fsl_pcib_devclass, 0, 0);
 
 static int
 fsl_pcib_probe(device_t dev)
diff --git a/sys/powerpc/ofw/ofw_cpu.c b/sys/powerpc/ofw/ofw_cpu.c
index 6cc6484..e830e3e 100644
--- a/sys/powerpc/ofw/ofw_cpu.c
+++ b/sys/powerpc/ofw/ofw_cpu.c
@@ -74,7 +74,7 @@ static driver_t ofw_cpulist_driver = {
 
 static devclass_t ofw_cpulist_devclass;
 
-DRIVER_MODULE(ofw_cpulist, nexus, ofw_cpulist_driver, ofw_cpulist_devclass,
+DRIVER_MODULE(ofw_cpulist, ofwbus, ofw_cpulist_driver, ofw_cpulist_devclass,
     0, 0);
 
 static int 
diff --git a/sys/powerpc/ofw/openpic_ofw.c b/sys/powerpc/ofw/openpic_ofw.c
index 2ddfb61..16b7575 100644
--- a/sys/powerpc/ofw/openpic_ofw.c
+++ b/sys/powerpc/ofw/openpic_ofw.c
@@ -93,7 +93,7 @@ static driver_t openpic_ofw_driver = {
 	sizeof(struct openpic_softc),
 };
 
-DRIVER_MODULE(openpic, nexus, openpic_ofw_driver, openpic_devclass, 0, 0);
+DRIVER_MODULE(openpic, ofwbus, openpic_ofw_driver, openpic_devclass, 0, 0);
 DRIVER_MODULE(openpic, simplebus, openpic_ofw_driver, openpic_devclass, 0, 0);
 DRIVER_MODULE(openpic, macio, openpic_ofw_driver, openpic_devclass, 0, 0);
 
diff --git a/sys/powerpc/powermac/cpcht.c b/sys/powerpc/powermac/cpcht.c
index 5e5b7b6..004f8f0 100644
--- a/sys/powerpc/powermac/cpcht.c
+++ b/sys/powerpc/powermac/cpcht.c
@@ -135,7 +135,7 @@ struct cpcht_softc {
 static devclass_t	cpcht_devclass;
 DEFINE_CLASS_1(pcib, cpcht_driver, cpcht_methods, sizeof(struct cpcht_softc),
     ofw_pci_driver);
-DRIVER_MODULE(cpcht, nexus, cpcht_driver, cpcht_devclass, 0, 0);
+DRIVER_MODULE(cpcht, ofwbus, cpcht_driver, cpcht_devclass, 0, 0);
 
 #define CPCHT_IOPORT_BASE	0xf4000000UL /* Hardwired */
 #define CPCHT_IOPORT_SIZE	0x00400000UL
diff --git a/sys/powerpc/powermac/grackle.c b/sys/powerpc/powermac/grackle.c
index 03c975d..b4a8a3b 100644
--- a/sys/powerpc/powermac/grackle.c
+++ b/sys/powerpc/powermac/grackle.c
@@ -102,7 +102,7 @@ static device_method_t	grackle_methods[] = {
 static devclass_t	grackle_devclass;
 DEFINE_CLASS_1(pcib, grackle_driver, grackle_methods,
     sizeof(struct grackle_softc), ofw_pci_driver);
-DRIVER_MODULE(grackle, nexus, grackle_driver, grackle_devclass, 0, 0);
+DRIVER_MODULE(grackle, ofwbus, grackle_driver, grackle_devclass, 0, 0);
 
 static int
 grackle_probe(device_t dev)
diff --git a/sys/powerpc/powermac/smu.c b/sys/powerpc/powermac/smu.c
index 5c622e3..5b74da3 100644
--- a/sys/powerpc/powermac/smu.c
+++ b/sys/powerpc/powermac/smu.c
@@ -210,7 +210,7 @@ static driver_t smu_driver = {
 
 static devclass_t smu_devclass;
 
-DRIVER_MODULE(smu, nexus, smu_driver, smu_devclass, 0, 0);
+DRIVER_MODULE(smu, ofwbus, smu_driver, smu_devclass, 0, 0);
 static MALLOC_DEFINE(M_SMU, "smu", "SMU Sensor Information");
 
 #define SMU_MAILBOX		0x8000860c
diff --git a/sys/powerpc/powermac/uninorth.c b/sys/powerpc/powermac/uninorth.c
index ab051a5..421e625 100644
--- a/sys/powerpc/powermac/uninorth.c
+++ b/sys/powerpc/powermac/uninorth.c
@@ -143,7 +143,7 @@ static devclass_t	unin_chip_devclass;
  */
 static device_t		unin_chip;
 
-DRIVER_MODULE(unin, nexus, unin_chip_driver, unin_chip_devclass, 0, 0);
+DRIVER_MODULE(unin, ofwbus, unin_chip_driver, unin_chip_devclass, 0, 0);
 
 /*
  * Add an interrupt to the dev's resource list if present
diff --git a/sys/powerpc/powermac/uninorthpci.c b/sys/powerpc/powermac/uninorthpci.c
index 5cf7a79..9da06ff 100644
--- a/sys/powerpc/powermac/uninorthpci.c
+++ b/sys/powerpc/powermac/uninorthpci.c
@@ -98,7 +98,7 @@ static devclass_t	uninorth_devclass;
 
 DEFINE_CLASS_1(pcib, uninorth_driver, uninorth_methods,
     sizeof(struct uninorth_softc), ofw_pci_driver);
-DRIVER_MODULE(uninorth, nexus, uninorth_driver, uninorth_devclass, 0, 0);
+DRIVER_MODULE(uninorth, ofwbus, uninorth_driver, uninorth_devclass, 0, 0);
 
 static int
 uninorth_probe(device_t dev)
diff --git a/sys/powerpc/powerpc/nexus.c b/sys/powerpc/powerpc/nexus.c
index 2e9bbe6..8a4d815 100644
--- a/sys/powerpc/powerpc/nexus.c
+++ b/sys/powerpc/powerpc/nexus.c
@@ -49,7 +49,6 @@ __FBSDID("$FreeBSD$");
 
 #include <dev/ofw/ofw_bus.h>
 #include <dev/ofw/ofw_bus_subr.h>
-#include <dev/ofw/ofw_nexus.h>
 #include <dev/ofw/openfirm.h>
 
 #include <machine/bus.h>
@@ -57,15 +56,12 @@ __FBSDID("$FreeBSD$");
 #include <machine/resource.h>
 
 /*
- * The nexus (which is a pseudo-bus actually) iterates over the nodes that
- * hang from the Open Firmware root node and adds them as devices to this bus
- * (except some special nodes which are excluded) so that drivers can be
- * attached to them.
- *
- * Additionally, interrupt setup/teardown and some resource management are
- * done at this level.
+ * The nexus handles root-level resource allocation requests and interrupt
+ * mapping. All direct subdevices of nexus are attached by DEVICE_IDENTIFY().
  */
 
+static device_probe_t nexus_probe;
+static device_attach_t nexus_attach;
 static bus_setup_intr_t nexus_setup_intr;
 static bus_teardown_intr_t nexus_teardown_intr;
 static bus_activate_resource_t nexus_activate_resource;
@@ -77,7 +73,12 @@ static bus_config_intr_t nexus_config_intr;
 static ofw_bus_map_intr_t nexus_ofw_map_intr;
 
 static device_method_t nexus_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe,		nexus_probe),
+	DEVMETHOD(device_attach,	nexus_attach),
+
 	/* Bus interface */
+	DEVMETHOD(bus_add_child,	bus_generic_add_child),
 	DEVMETHOD(bus_activate_resource,	nexus_activate_resource),
 	DEVMETHOD(bus_deactivate_resource,	nexus_deactivate_resource),
 	DEVMETHOD(bus_setup_intr,	nexus_setup_intr),
@@ -95,13 +96,31 @@ static device_method_t nexus_methods[] = {
 
 static devclass_t nexus_devclass;
 
-DEFINE_CLASS_1(nexus, nexus_driver, nexus_methods,
-    sizeof(struct ofw_nexus_softc), ofw_nexus_driver);
+DEFINE_CLASS_0(nexus, nexus_driver, nexus_methods, 1);
 EARLY_DRIVER_MODULE(nexus, root, nexus_driver, nexus_devclass, 0, 0,
     BUS_PASS_BUS);
 MODULE_VERSION(nexus, 1);
 
 static int
+nexus_probe(device_t dev)
+{
+        
+	device_quiet(dev);	/* suppress attach message for neatness */
+
+	return (BUS_PROBE_DEFAULT);
+}
+
+static int
+nexus_attach(device_t dev)
+{
+
+	bus_generic_probe(dev);
+	bus_generic_attach(dev);
+
+	return (0);
+}
+
+static int
 nexus_setup_intr(device_t bus __unused, device_t child, struct resource *r,
     int flags, driver_filter_t *filt, driver_intr_t *intr, void *arg,
     void **cookiep)
diff --git a/sys/powerpc/pseries/rtas_dev.c b/sys/powerpc/pseries/rtas_dev.c
index 36cb199..79d70e2 100644
--- a/sys/powerpc/pseries/rtas_dev.c
+++ b/sys/powerpc/pseries/rtas_dev.c
@@ -73,7 +73,7 @@ static driver_t rtasdev_driver = {
 
 static devclass_t rtasdev_devclass;
 
-DRIVER_MODULE(rtasdev, nexus, rtasdev_driver, rtasdev_devclass, 0, 0);
+DRIVER_MODULE(rtasdev, ofwbus, rtasdev_driver, rtasdev_devclass, 0, 0);
 
 static int
 rtasdev_probe(device_t dev)
diff --git a/sys/powerpc/pseries/rtas_pci.c b/sys/powerpc/pseries/rtas_pci.c
index 0835a27..90a7e6b 100644
--- a/sys/powerpc/pseries/rtas_pci.c
+++ b/sys/powerpc/pseries/rtas_pci.c
@@ -99,7 +99,7 @@ struct rtaspci_softc {
 static devclass_t	rtaspci_devclass;
 DEFINE_CLASS_1(pcib, rtaspci_driver, rtaspci_methods,
     sizeof(struct rtaspci_softc), ofw_pci_driver);
-DRIVER_MODULE(rtaspci, nexus, rtaspci_driver, rtaspci_devclass, 0, 0);
+DRIVER_MODULE(rtaspci, ofwbus, rtaspci_driver, rtaspci_devclass, 0, 0);
 
 static int
 rtaspci_probe(device_t dev)
diff --git a/sys/powerpc/pseries/vdevice.c b/sys/powerpc/pseries/vdevice.c
index e733a9d..d2c399b 100644
--- a/sys/powerpc/pseries/vdevice.c
+++ b/sys/powerpc/pseries/vdevice.c
@@ -103,7 +103,7 @@ static driver_t vdevice_driver = {
 
 static devclass_t vdevice_devclass;
 
-DRIVER_MODULE(vdevice, nexus, vdevice_driver, vdevice_devclass, 0, 0);
+DRIVER_MODULE(vdevice, ofwbus, vdevice_driver, vdevice_devclass, 0, 0);
 
 static int 
 vdevice_probe(device_t dev) 
diff --git a/sys/powerpc/pseries/xics.c b/sys/powerpc/pseries/xics.c
index 7bfbb3d..47b53d6 100644
--- a/sys/powerpc/pseries/xics.c
+++ b/sys/powerpc/pseries/xics.c
@@ -122,9 +122,9 @@ static driver_t xics_driver = {
 static devclass_t xicp_devclass;
 static devclass_t xics_devclass;
 
-EARLY_DRIVER_MODULE(xicp, nexus, xicp_driver, xicp_devclass, 0, 0,
+EARLY_DRIVER_MODULE(xicp, ofwbus, xicp_driver, xicp_devclass, 0, 0,
     BUS_PASS_INTERRUPT-1);
-EARLY_DRIVER_MODULE(xics, nexus, xics_driver, xics_devclass, 0, 0,
+EARLY_DRIVER_MODULE(xics, ofwbus, xics_driver, xics_devclass, 0, 0,
     BUS_PASS_INTERRUPT);
 
 static int
diff --git a/sys/powerpc/psim/iobus.c b/sys/powerpc/psim/iobus.c
index 6ed8cd3..6a6ac27 100644
--- a/sys/powerpc/psim/iobus.c
+++ b/sys/powerpc/psim/iobus.c
@@ -116,7 +116,7 @@ static driver_t iobus_driver = {
 
 devclass_t iobus_devclass;
 
-DRIVER_MODULE(iobus, nexus, iobus_driver, iobus_devclass, 0, 0);
+DRIVER_MODULE(iobus, ofwbus, iobus_driver, iobus_devclass, 0, 0);
 
 static int
 iobus_probe(device_t dev)