Rework mainbus and implement simplebus to be able to span a tree-like

topology based on device tree information.  Introduce a common attach
args structure to be used for all fdt-capable bus devices.

ok jsg@ kettenis@

21 files changed, 338 insertions, 150 deletions

diff --git a/sys/arch/arm/conf/files.arm b/sys/arch/arm/conf/files.arm
index cb11960f922..d4cdcc3a811 100644
--- a/sys/arch/arm/conf/files.arm
+++ b/sys/arch/arm/conf/files.arm
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.arm,v 1.35 2016/03/22 23:28:02 patrick Exp $
+#	$OpenBSD: files.arm,v 1.36 2016/05/02 08:15:55 patrick Exp $
 #	$NetBSD: files.arm,v 1.76 2003/11/05 12:53:15 scw Exp $
 
 # generic networking files
@@ -16,15 +16,24 @@ file	arch/arm/arm/disassem.c			ddb
 file	arch/arm/arm/fiq.c			fiq
 file	arch/arm/arm/fiq_subr.S			fiq
 
+define	fdt {}
+
 # mainbus files
-device	mainbus {}
+device	mainbus: fdt
 attach	mainbus at root
 file	arch/arm/mainbus/mainbus.c		mainbus
 
+device	simplebus: fdt
+attach	simplebus at fdt
+file	arch/arm/simplebus/simplebus.c		simplebus
+
+# FDT support
+file	dev/ofw/fdt.c
+
 include "arch/arm/cortex/files.cortex"
 
 device	cpu {}
-attach	cpu at mainbus with cpu_mainbus
+attach	cpu at fdt with cpu_mainbus
 file	arch/arm/mainbus/cpu_mainbus.c		cpu_mainbus
 
 
diff --git a/sys/arch/arm/cortex/cortex.c b/sys/arch/arm/cortex/cortex.c
index 913feb7963c..d2d6aa508b6 100644
--- a/sys/arch/arm/cortex/cortex.c
+++ b/sys/arch/arm/cortex/cortex.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cortex.c,v 1.4 2016/04/08 12:08:54 patrick Exp $	*/
+/*	$OpenBSD: cortex.c,v 1.5 2016/05/02 08:15:55 patrick Exp $	*/
 /* $NetBSD: mainbus.c,v 1.3 2001/06/13 17:52:43 nathanw Exp $ */
 
 /*
@@ -97,7 +97,7 @@ struct cfdriver cortex_cd = {
 int
 cortexmatch(struct device *parent, void *cfdata, void *aux)
 {
-	struct mainbus_attach_args *ma = aux;
+	union mainbus_attach_args *ma = aux;
 	struct cfdata *cf = (struct cfdata *)cfdata;
 	int cputype = cpufunc_id();
 
diff --git a/sys/arch/arm/cortex/files.cortex b/sys/arch/arm/cortex/files.cortex
index c0f4359fc2a..cb4200a091d 100644
--- a/sys/arch/arm/cortex/files.cortex
+++ b/sys/arch/arm/cortex/files.cortex
@@ -1,8 +1,8 @@
-#	$OpenBSD: files.cortex,v 1.3 2013/09/09 14:31:54 patrick Exp $
+#	$OpenBSD: files.cortex,v 1.4 2016/05/02 08:15:55 patrick Exp $
 
 # ARM core
 device	cortex {}
-attach	cortex at mainbus
+attach	cortex at fdt
 file	arch/arm/cortex/cortex.c		cortex
 
 device	ampintc
diff --git a/sys/arch/arm/include/fdt.h b/sys/arch/arm/include/fdt.h
new file mode 100644
index 00000000000..e7ba52faaae
--- /dev/null
+++ b/sys/arch/arm/include/fdt.h
@@ -0,0 +1,31 @@
+/* $OpenBSD: fdt.h,v 1.1 2016/05/02 08:15:55 patrick Exp $ */
+/*
+ * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef __ARM_FDT_H__
+#define __ARM_FDT_H__
+
+#define _ARM32_BUS_DMA_PRIVATE
+#include <machine/bus.h>
+
+struct fdt_attach_args {
+	const char		*fa_name;
+	int			 fa_node;
+	bus_space_tag_t		 fa_iot;
+	bus_dma_tag_t		 fa_dmat;
+};
+
+#endif /* __ARM_FDT_H__ */
diff --git a/sys/arch/arm/mainbus/cpu_mainbus.c b/sys/arch/arm/mainbus/cpu_mainbus.c
index 63de2094b39..e6726605d70 100644
--- a/sys/arch/arm/mainbus/cpu_mainbus.c
+++ b/sys/arch/arm/mainbus/cpu_mainbus.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu_mainbus.c,v 1.1 2004/02/01 05:09:49 drahn Exp $	*/
+/*	$OpenBSD: cpu_mainbus.c,v 1.2 2016/05/02 08:15:55 patrick Exp $	*/
 /*	$NetBSD: cpu_mainbus.c,v 1.3 2002/01/05 22:41:48 chris Exp $	*/
 
 /*
@@ -72,7 +72,7 @@ static void cpu_mainbus_attach (struct device *, struct device *, void *);
 static int
 cpu_mainbus_match(struct device *parent, void *vcf, void *aux)
 {
-	struct mainbus_attach_args *ma = aux;
+	union mainbus_attach_args *ma = aux;
 	struct cfdata *cf = (struct cfdata *)vcf;
 
 	return (strcmp(cf->cf_driver->cd_name, ma->ma_name) == 0);
diff --git a/sys/arch/arm/mainbus/mainbus.c b/sys/arch/arm/mainbus/mainbus.c
index 6ad3e8ff755..c42e0dcbdf6 100644
--- a/sys/arch/arm/mainbus/mainbus.c
+++ b/sys/arch/arm/mainbus/mainbus.c
@@ -1,45 +1,18 @@
-/*	$OpenBSD: mainbus.c,v 1.7 2013/05/30 16:15:01 deraadt Exp $	*/
-/* $NetBSD: mainbus.c,v 1.3 2001/06/13 17:52:43 nathanw Exp $ */
-
+/* $OpenBSD: mainbus.c,v 1.8 2016/05/02 08:15:55 patrick Exp $ */
 /*
- * Copyright (c) 1994,1995 Mark Brinicombe.
- * Copyright (c) 1994 Brini.
- * 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.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by Brini.
- * 4. The name of the company nor the name of the author may be used to
- *    endorse or promote products derived from this software without specific
- *    prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY BRINI ``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 BRINI 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.
- *
- * RiscBSD kernel project
+ * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
  *
- * mainbus.c
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
  *
- * mainbus configuration
- *
- * Created      : 15/12/94
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
 #include <sys/param.h>
@@ -47,78 +20,155 @@
 #include <sys/kernel.h>
 #include <sys/device.h>
 
+#include <dev/ofw/openfirm.h>
+
 #include <arm/mainbus/mainbus.h>
 
-/* Prototypes for functions provided */
+int mainbus_match(struct device *, void *, void *);
+void mainbus_attach(struct device *, struct device *, void *);
 
-int  mainbusmatch(struct device *, void *, void *);
-void mainbusattach(struct device *, struct device *, void *);
-int  mainbusprint(void *aux, const char *mainbus);
-int mainbussearch(struct device *,  void *, void *);
+void mainbus_attach_node(struct device *, int);
 
-/* attach and device structures for the device */
+int mainbus_legacy_search(struct device *, void *, void *);
+void mainbus_legacy_found(struct device *, char *);
+
+struct mainbus_softc {
+	struct device		 sc_dev;
+	bus_space_tag_t		 sc_iot;
+	bus_dma_tag_t		 sc_dmat;
+};
 
 struct cfattach mainbus_ca = {
-	sizeof(struct device), mainbusmatch, mainbusattach
+	sizeof(struct mainbus_softc), mainbus_match, mainbus_attach, NULL,
+	config_activate_children
 };
 
 struct cfdriver mainbus_cd = {
 	NULL, "mainbus", DV_DULL
 };
 
+struct arm32_bus_dma_tag mainbus_dma_tag = {
+	0,
+	0,
+	NULL,
+	_bus_dmamap_create,
+	_bus_dmamap_destroy,
+	_bus_dmamap_load,
+	_bus_dmamap_load_mbuf,
+	_bus_dmamap_load_uio,
+	_bus_dmamap_load_raw,
+	_bus_dmamap_unload,
+	_bus_dmamap_sync,
+	_bus_dmamem_alloc,
+	_bus_dmamem_free,
+	_bus_dmamem_map,
+	_bus_dmamem_unmap,
+	_bus_dmamem_mmap,
+};
+
 /*
- * int mainbusmatch(struct device *parent, struct cfdata *cf, void *aux)
+ * Mainbus takes care of FDT and non-FDT machines, so we
+ * always attach.
  */
-
 int
-mainbusmatch(struct device *parent, void *cf, void *aux)
+mainbus_match(struct device *parent, void *cfdata, void *aux)
 {
 	return (1);
 }
 
+void
+mainbus_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct mainbus_softc *sc = (struct mainbus_softc *)self;
+	char buffer[128];
+	int node;
+
+	if ((node = OF_peer(0)) == 0) {
+		printf(": no device tree\n");
+		config_search(mainbus_legacy_search, self, aux);
+		return;
+	}
+
+#ifdef CPU_ARMv7
+	extern struct bus_space armv7_bs_tag;
+	sc->sc_iot = &armv7_bs_tag;
+#endif
+	sc->sc_dmat = &mainbus_dma_tag;
+
+	if (OF_getprop(node, "model", buffer, sizeof(buffer)))
+		printf(": %s\n", buffer);
+	else
+		printf(": unknown model\n");
+
+	/* Attach CPU first. */
+	mainbus_legacy_found(self, "cpu");
+
+	/* TODO: Scan for interrupt controllers and attach them first? */
+
+	/* Scan the whole tree. */
+	for (node = OF_child(node);
+	    node != 0;
+	    node = OF_peer(node))
+	{
+		mainbus_attach_node(self, node);
+	}
+}
+
 /*
- * void mainbusattach(struct device *parent, struct device *self, void *aux)
- *
- * probe and attach all children
+ * Look for a driver that wants to be attached to this node.
  */
-
 void
-mainbusattach(struct device *parent, struct device *self, void *aux)
+mainbus_attach_node(struct device *self, int node)
 {
-	printf("\n");
+	struct mainbus_softc	*sc = (struct mainbus_softc *)self;
+	struct fdt_attach_args	 fa;
+	char			 buffer[128];
+
+	if (!OF_getprop(node, "compatible", buffer, sizeof(buffer)))
+		return;
+
+	if (OF_getprop(node, "status", buffer, sizeof(buffer)))
+		if (!strcmp(buffer, "disabled"))
+			return;
 
-	config_search(mainbussearch, self, aux);
+	memset(&fa, 0, sizeof(fa));
+	fa.fa_name = "";
+	fa.fa_node = node;
+	fa.fa_iot = sc->sc_iot;
+	fa.fa_dmat = sc->sc_dmat;
+
+	/* TODO: attach the device's clocks first? */
+
+	config_found(self, &fa, NULL);
 }
 
+/*
+ * Legacy support for SoCs that do not use FDT.
+ */
 int
-mainbussearch(struct device *parent, void *vcf, void *aux)
+mainbus_legacy_search(struct device *parent, void *match, void *aux)
 {
-	struct mainbus_attach_args ma;
-	struct cfdata *cf = vcf;
+	union mainbus_attach_args ma;
+	struct cfdata		*cf = match;
 
+	memset(&ma, 0, sizeof(ma));
 	ma.ma_name = cf->cf_driver->cd_name;
 
 	/* allow for devices to be disabled in UKC */
 	if ((*cf->cf_attach->ca_match)(parent, cf, &ma) == 0)
 		return 0;
 
-	config_attach(parent, cf, &ma, mainbusprint);
+	config_attach(parent, cf, &ma, NULL);
 	return 1;
 }
 
-/*
- * int mainbusprint(void *aux, const char *mainbus)
- *
- * print routine used during config of children
- */
-
-int
-mainbusprint(void *aux, const char *mainbus)
+void
+mainbus_legacy_found(struct device *self, char *name)
 {
-	struct mainbus_attach_args *ma = aux;
+	union mainbus_attach_args ma;
 
-	if (mainbus != NULL)
-		printf("%s at %s", ma->ma_name, mainbus);
+	memset(&ma, 0, sizeof(ma));
+	ma.ma_name = name;
 
-	return (UNCONF);
+	config_found(self, &ma, NULL);
 }
diff --git a/sys/arch/arm/mainbus/mainbus.h b/sys/arch/arm/mainbus/mainbus.h
index 3e1799628de..42a4076de34 100644
--- a/sys/arch/arm/mainbus/mainbus.h
+++ b/sys/arch/arm/mainbus/mainbus.h
@@ -1,51 +1,29 @@
-/*	$OpenBSD: mainbus.h,v 1.2 2011/09/22 17:45:59 miod Exp $	*/
-/* $NetBSD: mainbus.h,v 1.1 2001/02/24 19:38:02 reinoud Exp $ */
-
+/* $OpenBSD: mainbus.h,v 1.3 2016/05/02 08:15:55 patrick Exp $ */
 /*
- * Copyright (c) 1994,1995 Mark Brinicombe.
- * Copyright (c) 1994 Brini.
- * 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.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by Brini.
- * 4. The name of the company nor the name of the author may be used to
- *    endorse or promote products derived from this software without specific
- *    prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY BRINI ``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 BRINI 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.
- *
- * RiscBSD kernel project
- *
- * mainbus.h
+ * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
  *
- * mainbus configuration
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
  *
- * Created      : 15/12/94
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/*
- * mainbus driver attach arguments
- */
+#ifndef __MAINBUS_H__
+#define __MAINBUS_H__
 
-struct mainbus_attach_args {
-	const char	*ma_name;
+#include <arm/fdt.h>
+
+/* Passed as third arg to attach functions. */
+union mainbus_attach_args {
+	const char		*ma_name;
+	struct fdt_attach_args	 ma_faa;
 };
+
+#endif /* __MAINBUS_H__ */
diff --git a/sys/arch/arm/simplebus/simplebus.c b/sys/arch/arm/simplebus/simplebus.c
new file mode 100644
index 00000000000..d87044b2e02
--- /dev/null
+++ b/sys/arch/arm/simplebus/simplebus.c
@@ -0,0 +1,118 @@
+/* $OpenBSD: simplebus.c,v 1.1 2016/05/02 08:15:55 patrick Exp $ */
+/*
+ * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/device.h>
+
+#include <dev/ofw/openfirm.h>
+
+#include <arm/fdt.h>
+
+int simplebus_match(struct device *, void *, void *);
+void simplebus_attach(struct device *, struct device *, void *);
+
+void simplebus_attach_node(struct device *, int);
+
+struct simplebus_softc {
+	struct device		 sc_dev;
+	int			 sc_node;
+	bus_space_tag_t		 sc_iot;
+	bus_dma_tag_t		 sc_dmat;
+};
+
+struct cfattach simplebus_ca = {
+	sizeof(struct simplebus_softc), simplebus_match, simplebus_attach, NULL,
+	config_activate_children
+};
+
+struct cfdriver simplebus_cd = {
+	NULL, "simplebus", DV_DULL
+};
+
+/*
+ * Simplebus is a generic bus with no special casings.
+ */
+int
+simplebus_match(struct device *parent, void *cfdata, void *aux)
+{
+	struct fdt_attach_args *fa = (struct fdt_attach_args *)aux;
+	char buffer[128];
+
+	if (fa->fa_node == 0)
+		return (0);
+
+	if (!OF_getprop(fa->fa_node, "compatible", buffer,
+	    sizeof(buffer)))
+		return (0);
+
+	if (strcmp(buffer, "simple-bus"))
+		return (0);
+
+	return (1);
+}
+
+void
+simplebus_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct simplebus_softc *sc = (struct simplebus_softc *)self;
+	struct fdt_attach_args *fa = (struct fdt_attach_args *)aux;
+	int node;
+
+	sc->sc_node = fa->fa_node;
+	sc->sc_iot = fa->fa_iot;
+	sc->sc_dmat = fa->fa_dmat;
+
+	printf("\n");
+
+	/* Scan the whole tree. */
+	for (node = OF_child(sc->sc_node);
+	    node != 0;
+	    node = OF_peer(node))
+	{
+		simplebus_attach_node(self, node);
+	}
+}
+
+/*
+ * Look for a driver that wants to be attached to this node.
+ */
+void
+simplebus_attach_node(struct device *self, int node)
+{
+	struct simplebus_softc	*sc = (struct simplebus_softc *)self;
+	struct fdt_attach_args	 fa;
+	char			 buffer[128];
+
+	if (!OF_getprop(node, "compatible", buffer, sizeof(buffer)))
+		return;
+
+	if (OF_getprop(node, "status", buffer, sizeof(buffer)))
+		if (!strcmp(buffer, "disabled"))
+			return;
+
+	memset(&fa, 0, sizeof(fa));
+	fa.fa_name = "";
+	fa.fa_node = node;
+	fa.fa_iot = sc->sc_iot;
+	fa.fa_dmat = sc->sc_dmat;
+
+	/* TODO: attach the device's clocks first? */
+
+	config_found(self, &fa, NULL);
+}
diff --git a/sys/arch/arm/xscale/files.pxa2x0 b/sys/arch/arm/xscale/files.pxa2x0
index b73d7b71935..102d2df4119 100644
--- a/sys/arch/arm/xscale/files.pxa2x0
+++ b/sys/arch/arm/xscale/files.pxa2x0
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.pxa2x0,v 1.24 2014/10/18 12:21:56 miod Exp $
+#	$OpenBSD: files.pxa2x0,v 1.25 2016/05/02 08:15:55 patrick Exp $
 #	$NetBSD: files.pxa2x0,v 1.6 2004/05/01 19:09:14 thorpej Exp $
 #
 # Configuration info for Intel PXA2[51]0 CPU support
@@ -9,7 +9,7 @@ file	arch/arm/arm/softintr.c	# Use the generic ARM soft interrupt code.
 # PXA2[51]0's integrated peripherals bus.
 define	pxaip {[addr=-1], [size=0], [intr=-1], [index=-1]}
 device	pxaip
-attach	pxaip at mainbus
+attach	pxaip at fdt
 file	arch/arm/xscale/pxa2x0.c
 file	arch/arm/arm/irq_dispatch.S
 file	arch/arm/xscale/pxa2x0_space.c
diff --git a/sys/arch/armish/conf/files.armish b/sys/arch/armish/conf/files.armish
index 9bb866adbf8..62a038a5bee 100644
--- a/sys/arch/armish/conf/files.armish
+++ b/sys/arch/armish/conf/files.armish
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.armish,v 1.19 2016/01/15 13:20:06 tobiasu Exp $
+#	$OpenBSD: files.armish,v 1.20 2016/05/02 08:15:55 patrick Exp $
 
 maxpartitions   16
 maxusers	2 8 64
@@ -32,14 +32,14 @@ include "dev/i2c/files.i2c"
 # ARM i80321 files
 include "arch/arm/xscale/files.i80321"
 
-attach  iopxs at mainbus with iopxs_mainbus
+attach  iopxs at fdt with iopxs_mainbus
 file	arch/armish/dev/i80321_mainbus.c		iopxs_mainbus
 file	arch/armish/dev/pci_addr_fixup.c		iopxs
 file	arch/armish/dev/iq80321_pci.c			iopxs
 
 # IQ80310 on-board devices (including CPLD)
 device	obio {addr, [size = -1], [width = -1], [xint = -1]}: bus_space_generic
-attach	obio at mainbus
+attach	obio at fdt
 file	arch/armish/dev/obio.c				obio
 file	arch/armish/dev/obio_space.c			obio
 
diff --git a/sys/arch/armish/dev/i80321_mainbus.c b/sys/arch/armish/dev/i80321_mainbus.c
index ce711aac6fd..1004e79c96c 100644
--- a/sys/arch/armish/dev/i80321_mainbus.c
+++ b/sys/arch/armish/dev/i80321_mainbus.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: i80321_mainbus.c,v 1.10 2006/09/15 23:36:11 drahn Exp $ */
+/*	$OpenBSD: i80321_mainbus.c,v 1.11 2016/05/02 08:15:55 patrick Exp $ */
 /*	$NetBSD: i80321_mainbus.c,v 1.16 2005/12/15 01:44:00 briggs Exp $ */
 
 /*
@@ -91,7 +91,7 @@ int	i80321_mainbus_found;
 int
 i80321_mainbus_match(struct device *parent, void *match, void *aux)
 {
-	struct mainbus_attach_args *ma = aux;
+	union mainbus_attach_args *ma = aux;
 	struct cfdata *cf = match;
 
 	if (i80321_mainbus_found)
diff --git a/sys/arch/armish/dev/obio.c b/sys/arch/armish/dev/obio.c
index 0704ba7532e..c5186aaab93 100644
--- a/sys/arch/armish/dev/obio.c
+++ b/sys/arch/armish/dev/obio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: obio.c,v 1.3 2006/06/01 17:06:16 drahn Exp $	*/
+/*	$OpenBSD: obio.c,v 1.4 2016/05/02 08:15:55 patrick Exp $	*/
 /*	$NetBSD: obio.c,v 1.14 2005/12/11 12:17:09 christos Exp $	*/
 
 /*
@@ -73,7 +73,7 @@ int	obio_found;
 int
 obio_match(struct device *parent, void *match, void *aux)
 {
-	struct mainbus_attach_args *ma = aux;
+	union mainbus_attach_args *ma = aux;
 	struct cfdata *cf = match;
 
 	if (obio_found)
diff --git a/sys/arch/armv7/conf/GENERIC b/sys/arch/armv7/conf/GENERIC
index ccb34cea778..953984dffe9 100644
--- a/sys/arch/armv7/conf/GENERIC
+++ b/sys/arch/armv7/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.8 2016/04/24 17:30:31 matthieu Exp $
+#	$OpenBSD: GENERIC,v 1.9 2016/05/02 08:15:55 patrick Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -28,6 +28,7 @@ config		bsd	swap generic
 
 # The main bus device
 mainbus0	at root
+simplebus*	at fdt?
 cpu0		at mainbus?
 
 # Cortex-A9
diff --git a/sys/arch/armv7/conf/RAMDISK b/sys/arch/armv7/conf/RAMDISK
index 8c0c22ba574..cda7119663b 100644
--- a/sys/arch/armv7/conf/RAMDISK
+++ b/sys/arch/armv7/conf/RAMDISK
@@ -1,4 +1,4 @@
-#	$OpenBSD: RAMDISK,v 1.7 2015/09/13 14:43:42 deraadt Exp $
+#	$OpenBSD: RAMDISK,v 1.8 2016/05/02 08:15:55 patrick Exp $
 
 machine		armv7 arm
 
@@ -27,6 +27,7 @@ config		bsd root on rd0a swap on rd0b
 
 # The main bus device
 mainbus0	at root
+simplebus*	at fdt?
 cpu0		at mainbus?
 
 # Cortex-A9
diff --git a/sys/arch/armv7/conf/files.armv7 b/sys/arch/armv7/conf/files.armv7
index 7a9dc6a811e..847fbcbf013 100644
--- a/sys/arch/armv7/conf/files.armv7
+++ b/sys/arch/armv7/conf/files.armv7
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.armv7,v 1.16 2016/04/24 00:57:23 patrick Exp $
+#	$OpenBSD: files.armv7,v 1.17 2016/05/02 08:15:55 patrick Exp $
 
 maxpartitions	16
 maxusers	2 8 64
@@ -8,9 +8,6 @@ major	{sd = 24}
 major	{cd = 26}
 major	{rd = 18}
 
-define	fdt {}
-file	dev/ofw/fdt.c
-
 file	arch/arm/arm/conf.c
 
 #interrupt API layer
diff --git a/sys/arch/armv7/exynos/files.exynos b/sys/arch/armv7/exynos/files.exynos
index 89c419322f3..ca121ce8b7c 100644
--- a/sys/arch/armv7/exynos/files.exynos
+++ b/sys/arch/armv7/exynos/files.exynos
@@ -1,8 +1,8 @@
-#	$OpenBSD: files.exynos,v 1.3 2016/04/24 00:57:23 patrick Exp $
+#	$OpenBSD: files.exynos,v 1.4 2016/05/02 08:15:55 patrick Exp $
 
 define exynos {}
 device exynos: exynos
-attach exynos at mainbus
+attach exynos at fdt
 file	arch/armv7/exynos/exynos_machdep.c	exynos	needs-flag
 file	arch/armv7/exynos/exynos.c		exynos
 file	arch/armv7/exynos/exynos4.c		exynos
diff --git a/sys/arch/armv7/imx/files.imx b/sys/arch/armv7/imx/files.imx
index 3e7ec3351f6..0294af62ad6 100644
--- a/sys/arch/armv7/imx/files.imx
+++ b/sys/arch/armv7/imx/files.imx
@@ -1,8 +1,8 @@
-#	$OpenBSD: files.imx,v 1.3 2015/05/15 15:35:43 jsg Exp $
+#	$OpenBSD: files.imx,v 1.4 2016/05/02 08:15:55 patrick Exp $
 
 define imx {}
 device imx: imx
-attach imx at mainbus
+attach imx at fdt
 file	arch/armv7/imx/imx_machdep.c		imx	needs-flag
 file	arch/armv7/imx/imx.c			imx
 file	arch/armv7/imx/imx6.c
diff --git a/sys/arch/armv7/include/fdt.h b/sys/arch/armv7/include/fdt.h
new file mode 100644
index 00000000000..5ba05d2d1b2
--- /dev/null
+++ b/sys/arch/armv7/include/fdt.h
@@ -0,0 +1,3 @@
+/* $OpenBSD: fdt.h,v 1.1 2016/05/02 08:15:55 patrick Exp $ */
+
+#include <arm/fdt.h>
diff --git a/sys/arch/armv7/omap/files.omap b/sys/arch/armv7/omap/files.omap
index 8fd446f32de..a50b93e6509 100644
--- a/sys/arch/armv7/omap/files.omap
+++ b/sys/arch/armv7/omap/files.omap
@@ -1,8 +1,8 @@
-#	$OpenBSD: files.omap,v 1.7 2015/05/15 15:35:43 jsg Exp $
+#	$OpenBSD: files.omap,v 1.8 2016/05/02 08:15:55 patrick Exp $
 
 define omap {}
 device omap: omap
-attach omap at mainbus
+attach omap at fdt
 file	arch/armv7/omap/omap_machdep.c		omap	needs-flag
 file	arch/armv7/omap/omap.c			omap
 file	arch/armv7/omap/omap3.c
diff --git a/sys/arch/armv7/sunxi/files.sunxi b/sys/arch/armv7/sunxi/files.sunxi
index 80c4ba4a9b4..521b2d7da2b 100644
--- a/sys/arch/armv7/sunxi/files.sunxi
+++ b/sys/arch/armv7/sunxi/files.sunxi
@@ -1,8 +1,8 @@
-#	$OpenBSD: files.sunxi,v 1.3 2015/05/15 15:35:43 jsg Exp $
+#	$OpenBSD: files.sunxi,v 1.4 2016/05/02 08:15:55 patrick Exp $
 
 define	sunxi {}
 device	sunxi: sunxi
-attach	sunxi at mainbus
+attach	sunxi at fdt
 file	arch/armv7/sunxi/sunxi_machdep.c	sunxi	needs-flag
 file	arch/armv7/sunxi/sunxi.c		sunxi
 file	arch/armv7/sunxi/sun4i.c
diff --git a/sys/arch/armv7/vexpress/files.vexpress b/sys/arch/armv7/vexpress/files.vexpress
index dd7db10932d..a06d39415fc 100644
--- a/sys/arch/armv7/vexpress/files.vexpress
+++ b/sys/arch/armv7/vexpress/files.vexpress
@@ -1,8 +1,8 @@
-#	$OpenBSD: files.vexpress,v 1.2 2015/06/14 05:01:31 jsg Exp $
+#	$OpenBSD: files.vexpress,v 1.3 2016/05/02 08:15:55 patrick Exp $
 
 define vexpress {}
 device vexpress: vexpress
-attach vexpress at mainbus
+attach vexpress at fdt
 file	arch/armv7/vexpress/vexpress_machdep.c	vexpress needs-flag
 file	arch/armv7/vexpress/vexpress.c		vexpress
 file	arch/armv7/vexpress/vexpress_a9.c	vexpress