Index: head/sys/conf/files.powerpc
===================================================================
--- head/sys/conf/files.powerpc
+++ head/sys/conf/files.powerpc
@@ -129,6 +129,7 @@
 powerpc/mambo/mambo.c		optional	mambo
 powerpc/mambo/mambo_console.c	optional	mambo
 powerpc/mambo/mambo_disk.c	optional	mambo
+powerpc/mikrotik/platform_rb.c	optional	mikrotik
 powerpc/mpc85xx/atpic.c		optional	mpc85xx isa
 powerpc/mpc85xx/ds1553_bus_fdt.c	optional	ds1553 fdt
 powerpc/mpc85xx/ds1553_core.c	optional	ds1553
Index: head/sys/conf/options.powerpc
===================================================================
--- head/sys/conf/options.powerpc
+++ head/sys/conf/options.powerpc
@@ -32,3 +32,4 @@
 # AGP debugging support
 AGP_DEBUG		opt_agp.h
 
+MIKROTIK
Index: head/sys/dev/fdt/fdt_slicer.c
===================================================================
--- head/sys/dev/fdt/fdt_slicer.c
+++ head/sys/dev/fdt/fdt_slicer.c
@@ -43,7 +43,7 @@
 #endif
 
 int
-flash_fill_slices(device_t dev, struct flash_slice *slices, int *slices_num)
+fdt_flash_fill_slices(device_t dev, struct flash_slice *slices, int *slices_num)
 {
 	char *slice_name;
 	phandle_t dt_node, dt_child;
Index: head/sys/geom/geom_flashmap.c
===================================================================
--- head/sys/geom/geom_flashmap.c
+++ head/sys/geom/geom_flashmap.c
@@ -70,6 +70,8 @@
 static void g_flashmap_config(struct gctl_req *, struct g_class *,
     const char *);
 static int g_flashmap_load(device_t, struct g_flashmap_head *);
+static int (*flash_fill_slices)(device_t, struct flash_slice *, int *) =
+    fdt_flash_fill_slices;
 
 MALLOC_DECLARE(M_FLASHMAP);
 MALLOC_DEFINE(M_FLASHMAP, "geom_flashmap", "GEOM flash memory slicer class");
@@ -230,7 +232,8 @@
 
 	buf_size = sizeof(struct flash_slice) * FLASH_SLICES_MAX_NUM;
 	slices = malloc(buf_size, M_FLASHMAP, M_WAITOK | M_ZERO);
-	if (flash_fill_slices(dev, slices, &nslices) == 0) {
+	if (flash_fill_slices &&
+	    flash_fill_slices(dev, slices, &nslices) == 0) {
 		for (i = 0; i < nslices; i++) {
 			slice = malloc(sizeof(struct g_flashmap_slice),
 			    M_FLASHMAP, M_WAITOK);
@@ -247,6 +250,12 @@
 	return (nslices);
 }
 
+void flash_register_slicer(int (*slicer)(device_t, struct flash_slice *, int *))
+{
+
+	flash_fill_slices = slicer;
+}
+
 static struct g_class g_flashmap_class = {
 	.name = FLASHMAP_CLASS_NAME,
 	.version = G_VERSION,
Index: head/sys/powerpc/mikrotik/platform_rb.c
===================================================================
--- head/sys/powerpc/mikrotik/platform_rb.c
+++ head/sys/powerpc/mikrotik/platform_rb.c
@@ -0,0 +1,123 @@
+/*-
+ * Copyright (c) 2015 Justin Hibbits
+ * 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 ``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 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/kernel.h>
+#include <sys/bus.h>
+#include <sys/malloc.h>
+#include <sys/slicer.h>
+#include <sys/smp.h>
+
+#include <machine/platform.h>
+#include <machine/platformvar.h>
+
+#include <dev/nand/nand.h>
+#include <dev/ofw/openfirm.h>
+#include <geom/geom_disk.h>
+
+#include <powerpc/mpc85xx/mpc85xx.h>
+
+#include "platform_if.h"
+
+static int rb_probe(platform_t);
+static int rb_attach(platform_t);
+
+static platform_method_t rb_methods[] = {
+	PLATFORMMETHOD(platform_probe,		rb_probe),
+	PLATFORMMETHOD(platform_attach,		rb_attach),
+	PLATFORMMETHOD_END
+};
+
+DEFINE_CLASS_1(rb, rb_platform, rb_methods, 0, mpc85xx_platform);
+
+PLATFORM_DEF(rb_platform);
+
+/* Slicer operates on the NAND controller, so we have to find the chip. */
+static int
+rb_nand_slicer(device_t dev, struct flash_slice *slices, int *nslices)
+{
+	struct nand_chip *chip;
+	device_t *children;
+	int n;
+
+	if (device_get_children(dev, &children, &n) != 0) {
+		panic("Slicer called on controller with no child!");
+	}
+	dev = children[0];
+	free(children, M_TEMP);
+
+	if (device_get_children(dev, &children, &n) != 0) {
+		panic("Slicer called on controller with nandbus but no child!");
+	}
+	dev = children[0];
+	free(children, M_TEMP);
+
+	chip = device_get_softc(dev);
+	*nslices = 2;
+	slices[0].base = 0;
+	slices[0].size = 4 * 1024 * 1024;
+	slices[0].label = "boot";
+
+	slices[1].base = 4 * 1024 * 1024;
+	slices[1].size = chip->ndisk->d_mediasize - slices[0].size;
+	slices[1].label = "rootfs";
+
+	return (0);
+}
+
+static int
+rb_probe(platform_t plat)
+{
+	phandle_t rootnode;
+	char model[32];
+
+	rootnode = OF_finddevice("/");
+
+	if (OF_getprop(rootnode, "model", model, sizeof(model)) > 0) {
+		if (strcmp(model, "RB800") == 0)
+			return (BUS_PROBE_SPECIFIC);
+	}
+
+	return (ENXIO);
+}
+
+static int
+rb_attach(platform_t plat)
+{
+	int error;
+
+	error = mpc85xx_attach(plat);
+	if (error)
+		return (error);
+
+	flash_register_slicer(rb_nand_slicer);
+
+	return (0);
+}
Index: head/sys/sys/slicer.h
===================================================================
--- head/sys/sys/slicer.h
+++ head/sys/sys/slicer.h
@@ -45,7 +45,8 @@
 };
 
 #ifdef _KERNEL
-int flash_fill_slices(device_t, struct flash_slice *, int *);
+int fdt_flash_fill_slices(device_t, struct flash_slice *, int *) __weak_symbol;
+void flash_register_slicer(int (*)(device_t, struct flash_slice *, int *));
 #endif /* _KERNEL */
 
 #endif /* _FLASH_SLICER_H_ */