Index: sys/arm64/include/xen/xen-os.h
===================================================================
--- sys/arm64/include/xen/xen-os.h
+++ sys/arm64/include/xen/xen-os.h
@@ -39,6 +39,12 @@
 
 #ifndef __ASSEMBLY__
 
+/* Right now the device-tree is the only implemented detection method */
+#define xen_early_probe() xen_dt_probe()
+
+/* Early initializer, returns success/failure identical to xen_domain() */
+extern int xen_dt_probe(void);
+
 #define PCPU_ID_GET(cpu) (cpu)
 
 static inline bool
Index: sys/conf/files
===================================================================
--- sys/conf/files
+++ sys/conf/files
@@ -3535,6 +3535,7 @@
 dev/xen/bus/xenpv.c		optional xenhvm
 dev/xen/console/xen_console.c	optional xenhvm
 dev/xen/control/control.c	optional xenhvm
+dev/xen/devicetree/xen-dt.c	optional xenhvm fdt
 dev/xen/efi/pvefi.c		optional xenhvm efirt
 dev/xen/grant_table/grant_table.c	optional xenhvm
 dev/xen/netback/netback.c	optional xenhvm
Index: sys/dev/xen/devicetree/xen-dt.c
===================================================================
--- /dev/null
+++ sys/dev/xen/devicetree/xen-dt.c
@@ -0,0 +1,172 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2014 Julien Grall
+ * Copyright (c) 2021 Elliott Mitchell
+ *
+ * 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/bus.h>
+#include <sys/kernel.h>
+#include <sys/pcpu.h>
+#include <sys/rman.h>
+#include <sys/module.h>
+
+#include <vm/vm.h>
+#include <vm/pmap.h>
+#include <vm/vm_page.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include <dev/fdt/fdt_common.h>
+
+#include <xen/xen-os.h>
+#include <xen/xen_intr.h>
+#include <xen/hypervisor.h>
+#include <xen/interface/vcpu.h>
+#include <xen/features.h>
+
+
+DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
+DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
+
+int
+xen_dt_probe(void)
+{
+	/*
+	 * Short-circuit extra attempts at looking for Xen
+	 */
+	if (xen_domain())
+		return (1);
+
+	/*
+	 * The device tree contains the node /hypervisor with the compatible
+	 * string "xen,xen" when the OS will run on top of Xen.
+	 */
+	if (ofw_bus_node_is_compatible(OF_finddevice("/hypervisor"), "xen,xen") == 0)
+		return (0);
+
+	xen_domain_type = XEN_HVM_DOMAIN;
+	vm_guest = VM_GUEST_XEN;
+	setup_xen_features();
+
+	return (1);
+}
+
+/* in case of console being disabled, probe again as a fallback */
+C_SYSINIT(xen_probe_fdt, SI_SUB_HYPERVISOR, SI_ORDER_FIRST, (sysinit_cfunc_t)xen_dt_probe, NULL);
+
+/* xen_handle_shared_info() won't work during console probe, thus this */
+C_SYSINIT(xen_shared_info, SI_SUB_HYPERVISOR, SI_ORDER_SECOND, (sysinit_cfunc_t)xen_handle_shared_info, NULL);
+
+
+struct xen_softc {
+	struct resource		*intr;
+	void			*cookie;
+	int			rid;
+};
+
+struct xen_softc *xen_sc = NULL;
+
+static int
+xen_probe(device_t dev)
+{
+	if (!ofw_bus_status_okay(dev))
+		return (ENXIO);
+
+	if (!ofw_bus_is_compatible(dev, "xen,xen"))
+		return (ENXIO);
+
+	device_set_desc(dev, "Xen ARM device-tree");
+
+	return (BUS_PROBE_DEFAULT);
+}
+
+static int
+xen_attach(device_t dev)
+{
+	struct xen_softc *sc;
+	struct vcpu_register_vcpu_info info;
+	struct vcpu_info *vcpu_info;
+	vm_paddr_t phys;
+	int rc, cpu;
+
+	if (xen_sc != NULL)
+		return (ENXIO);
+
+	sc = device_get_softc(dev);
+
+	/* TODO: Move to a proper function */
+	vcpu_info = DPCPU_PTR(vcpu_local_info);
+	cpu = PCPU_GET(cpuid);
+	phys = vtophys(vcpu_info);
+	info.mfn = phys >> PAGE_SHIFT_4K;
+	info.offset = phys & PAGE_MASK_4K;
+
+	rc = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
+	KASSERT(rc == 0, ("Unable to register cpu %u\n", cpu));
+	DPCPU_SET(vcpu_info, vcpu_info);
+
+
+	/* Resources */
+	sc->intr = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->rid, RF_ACTIVE);
+	if (sc->intr == NULL) {
+		panic("Unable to retrieve Xen event channel interrupt");
+		return (ENXIO);
+	}
+
+	xen_sc = sc;
+
+	/* Setup and enable the event channel interrupt */
+	if (bus_setup_intr(dev, sc->intr, INTR_TYPE_MISC|INTR_MPSAFE,
+		   xen_intr_handle_upcall, NULL, sc, &sc->cookie)) {
+		panic("Could not setup event channel interrupt");
+		return (ENXIO);
+	}
+
+	return (0);
+}
+
+static device_method_t xen_methods[] = {
+	DEVMETHOD(device_probe, xen_probe),
+	DEVMETHOD(device_attach, xen_attach),
+	{ 0, 0 }
+};
+
+static driver_t xen_driver = {
+	"xen-dt",
+	xen_methods,
+	sizeof(struct xen_softc),
+};
+
+static devclass_t xen_devclass;
+
+DRIVER_MODULE(xen, simplebus, xen_driver, xen_devclass, 0, 0);
+DRIVER_MODULE(xen, ofwbus, xen_driver, xen_devclass, 0, 0);