Index: sys/conf/files.powerpc
===================================================================
--- sys/conf/files.powerpc
+++ sys/conf/files.powerpc
@@ -161,6 +161,7 @@
 powerpc/ofw/ofwcall64.S		optional	aim powerpc64
 powerpc/ofw/openpic_ofw.c	standard
 powerpc/ofw/rtas.c		optional	aim
+powerpc/ofw/ofw_initrd.c	optional	md_root_mem powerpc64
 powerpc/powermac/ata_kauai.c	optional	powermac ata | powermac atamacio
 powerpc/powermac/ata_macio.c	optional	powermac ata | powermac atamacio
 powerpc/powermac/ata_dbdma.c	optional	powermac ata | powermac atamacio
Index: sys/powerpc/ofw/ofw_initrd.c
===================================================================
--- /dev/null
+++ sys/powerpc/ofw/ofw_initrd.c
@@ -0,0 +1,157 @@
+/*-
+ * Copyright (C) 2018 Breno Leitao
+ *
+ * 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 ``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 TOOLS GMBH 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/kernel.h>
+#include <sys/systm.h>
+#include <sys/module.h>
+#include <sys/types.h>
+#include <sys/proc.h>
+
+#include <vm/vm.h>
+#include <vm/pmap.h>
+
+#include <machine/bus.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include "opt_md.h"
+
+#ifdef MD_ROOT_MEM
+extern u_char *mfs_root;
+extern uint32_t mfs_root_size;
+#else
+#warning "MD_ROOT_MEM should be set to use ofw initrd as a md device"
+#endif
+
+/* bus entry points */
+static int ofw_initrd_probe(device_t dev);
+static int ofw_initrd_attach(device_t dev);
+static void ofw_initrd_identify(driver_t *driver, device_t parent);
+
+struct ofw_initrd_softc {
+	device_t	sc_dev;
+	vm_paddr_t	start;
+	vm_paddr_t	end;
+};
+
+static int
+ofw_initrd_probe(device_t dev)
+{
+	phandle_t chosen;
+	pcell_t cell[2];
+
+	/* limit this device to one unit */
+	if (device_get_unit(dev) != 0)
+		return (ENXIO);
+
+	chosen = OF_finddevice("/chosen");
+	if (chosen <= 0) {
+		return (ENXIO);
+	}
+
+	if (!OF_hasprop(chosen, "linux,initrd-start") &&
+	    !OF_hasprop(chosen, "linux,initrd-end"))
+		return (ENXIO);
+
+	device_set_desc(dev, "OFW initrd memregion loader");
+	return BUS_PROBE_DEFAULT;
+}
+
+static int
+ofw_initrd_attach(device_t dev)
+{
+	struct ofw_initrd_softc *sc;
+	vm_paddr_t start, end;
+	phandle_t chosen;
+	pcell_t cell[2];
+	ssize_t size;
+
+	sc = device_get_softc(dev);
+
+	chosen = OF_finddevice("/chosen");
+	if (chosen <= 0) {
+		device_printf(dev, "/chosen not found\n");
+		return (ENXIO);
+	}
+
+	size = OF_getencprop(chosen, "linux,initrd-start", cell, sizeof(cell));
+	if (size == 4)
+		start = cell[0];
+	else if (size == 8)
+		start = (uint64_t)cell[0] << 32 | cell[1];
+	else {
+		device_printf(dev, "Wrong linux,initrd-start size\n");
+		return (ENXIO);
+	}
+
+	size = OF_getencprop(chosen, "linux,initrd-end", cell, sizeof(cell));
+	if (size == 4)
+		end = cell[0];
+	else if (size == 8)
+		end = (uint64_t)cell[0] << 32 | cell[1];
+	else{
+		device_printf(dev, "Wrong linux,initrd-end size\n");
+		return (ENXIO);
+	}
+
+	if (end - start > 0) {
+		mfs_root = (u_char *) PHYS_TO_DMAP(start);
+		mfs_root_size = end - start;
+
+		return (0);
+	}
+
+	return (ENXIO);
+}
+
+static void
+ofw_initrd_identify(driver_t *driver, device_t parent)
+{
+	if (BUS_ADD_CHILD(parent, 10, "initrd", -1) == NULL)
+		device_printf(parent, "add ofw_initrd child failed\n");
+}
+
+static device_method_t ofw_initrd_methods[] = {
+	DEVMETHOD(device_identify,	ofw_initrd_identify),
+	DEVMETHOD(device_probe,		ofw_initrd_probe),
+	DEVMETHOD(device_attach,	ofw_initrd_attach),
+	DEVMETHOD_END
+};
+
+static driver_t ofw_initrd_driver = {
+        "ofw_initrd",
+        ofw_initrd_methods,
+        sizeof(struct ofw_initrd_softc)
+};
+
+static devclass_t ofw_initrd_devclass;
+
+DRIVER_MODULE(ofw_initrd, ofwbus, ofw_initrd_driver, ofw_initrd_devclass,
+    NULL, NULL);