diff --git a/sys/dev/fdt/fdt_common.c b/sys/dev/fdt/fdt_common.c
index 0ae5b2b31610..70bf744c3d77 100644
--- a/sys/dev/fdt/fdt_common.c
+++ b/sys/dev/fdt/fdt_common.c
@@ -71,6 +71,8 @@ vm_offset_t fdt_immr_size;
 
 struct fdt_ic_list fdt_ic_list_head = SLIST_HEAD_INITIALIZER(fdt_ic_list_head);
 
+static int fdt_is_compatible(phandle_t, const char *);
+
 static int
 fdt_get_range_by_busaddr(phandle_t node, u_long addr, u_long *base,
     u_long *size)
@@ -202,6 +204,77 @@ fdt_get_range(phandle_t node, int range_id, u_long *base, u_long *size)
 	return (0);
 }
 
+int
+fdt_immr_addr(vm_offset_t immr_va)
+{
+	phandle_t node;
+	u_long base, size;
+	int r;
+
+	/*
+	 * Try to access the SOC node directly i.e. through /aliases/.
+	 */
+	if ((node = OF_finddevice("soc")) != -1)
+		if (fdt_is_compatible(node, "simple-bus"))
+			goto moveon;
+	/*
+	 * Find the node the long way.
+	 */
+	if ((node = OF_finddevice("/")) == -1)
+		return (ENXIO);
+
+	if ((node = fdt_find_compatible(node, "simple-bus", 0)) == 0)
+		return (ENXIO);
+
+moveon:
+	if ((r = fdt_get_range(node, 0, &base, &size)) == 0) {
+		fdt_immr_pa = base;
+		fdt_immr_va = immr_va;
+		fdt_immr_size = size;
+	}
+
+	return (r);
+}
+
+/*
+ * This routine is an early-usage version of the ofw_bus_is_compatible() when
+ * the ofw_bus I/F is not available (like early console routines and similar).
+ * Note the buffer has to be on the stack since malloc() is usually not
+ * available in such cases either.
+ */
+static int
+fdt_is_compatible(phandle_t node, const char *compatstr)
+{
+	char buf[FDT_COMPAT_LEN];
+	char *compat;
+	int len, onelen, l, rv;
+
+	if ((len = OF_getproplen(node, "compatible")) <= 0)
+		return (0);
+
+	compat = (char *)&buf;
+	bzero(compat, FDT_COMPAT_LEN);
+
+	if (OF_getprop(node, "compatible", compat, FDT_COMPAT_LEN) < 0)
+		return (0);
+
+	onelen = strlen(compatstr);
+	rv = 0;
+	while (len > 0) {
+		if (strncasecmp(compat, compatstr, onelen) == 0) {
+			/* Found it. */
+			rv = 1;
+			break;
+		}
+		/* Slide to the next sub-string. */
+		l = strlen(compat) + 1;
+		compat += l;
+		len -= l;
+	}
+
+	return (rv);
+}
+
 int
 fdt_is_compatible_strict(phandle_t node, const char *compatible)
 {
@@ -230,7 +303,7 @@ fdt_find_compatible(phandle_t start, const char *compat, int strict)
 	 * matching 'compatible' property.
 	 */
 	for (child = OF_child(start); child != 0; child = OF_peer(child))
-		if (ofw_bus_node_is_compatible(child, compat)) {
+		if (fdt_is_compatible(child, compat)) {
 			if (strict)
 				if (!fdt_is_compatible_strict(child, compat))
 					continue;
@@ -249,7 +322,7 @@ fdt_depth_search_compatible(phandle_t start, const char *compat, int strict)
 	 * matching 'compatible' property.
 	 */
 	for (node = OF_child(start); node != 0; node = OF_peer(node)) {
-		if (ofw_bus_node_is_compatible(node, compat) &&
+		if (fdt_is_compatible(node, compat) && 
 		    (strict == 0 || fdt_is_compatible_strict(node, compat))) {
 			return (node);
 		}