Index: sys/arm/broadcom/bcm2835/bcm2835_firmware.c
===================================================================
--- sys/arm/broadcom/bcm2835/bcm2835_firmware.c
+++ sys/arm/broadcom/bcm2835/bcm2835_firmware.c
@@ -55,8 +55,6 @@
 	{NULL,					0}
 };
 
-static bool bcm2835_firmware_get_revision(device_t, uint32_t *);
-
 static int sysctl_bcm2835_firmware_get_revision(SYSCTL_HANDLER_ARGS);
 
 static int
@@ -79,12 +77,16 @@
 	struct sysctl_ctx_list *ctx;
 	struct sysctl_oid *tree_node;
 	struct sysctl_oid_list *tree;
+	phandle_t node;
 
 	sc = device_get_softc(dev);
 	sc->sc_dev = dev;
 
 	/* TODO: Use the mboxes property to find the mbox */
 
+	node = ofw_bus_get_node(dev);
+	OF_device_register_xref(OF_xref_from_node(node), dev);
+
 	ctx = device_get_sysctl_ctx(sc->sc_dev);
 	tree_node = device_get_sysctl_tree(sc->sc_dev);
 	tree = SYSCTL_CHILDREN(tree_node);
Index: sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
===================================================================
--- sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
+++ sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
@@ -231,6 +231,31 @@
 	    (uintptr_t)which, (uintptr_t)fault, (uintptr_t)fltoffs);
 }
 
+static void
+dtrace_load64(uint64_t *addr, struct trapframe *frame, u_int reg)
+{
+
+	KASSERT(reg <= 31, ("dtrace_load64: Invalid register %u", reg));
+	if (reg < nitems(frame->tf_x))
+		frame->tf_x[reg] = *addr;
+	else if (reg == 30) /* lr */
+		frame->tf_lr = *addr;
+	/* Nothing to do for load to xzr */
+}
+
+static void
+dtrace_store64(uint64_t *addr, struct trapframe *frame, u_int reg)
+{
+
+	KASSERT(reg <= 31, ("dtrace_store64: Invalid register %u", reg));
+	if (reg < nitems(frame->tf_x))
+		*addr = frame->tf_x[reg];
+	else if (reg == 30) /* lr */
+		*addr = frame->tf_lr;
+	else if (reg == 31) /* xzr */
+		*addr = 0;
+}
+
 static int
 dtrace_invop_start(struct trapframe *frame)
 {
@@ -258,12 +283,12 @@
 				sp -= (~offs & OFFSET_MASK) + 1;
 			else
 				sp += (offs);
-			*(sp + 0) = frame->tf_x[arg1];
-			*(sp + 1) = frame->tf_x[arg2];
+			dtrace_store64(sp + 0, frame, arg1);
+			dtrace_store64(sp + 1, frame, arg2);
 			break;
 		case LDP_64:
-			frame->tf_x[arg1] = *(sp + 0);
-			frame->tf_x[arg2] = *(sp + 1);
+			dtrace_load64(sp, frame, arg1);
+			dtrace_load64(sp + 1, frame, arg2);
 			if (offs >> (OFFSET_SIZE - 1))
 				sp -= (~offs & OFFSET_MASK) + 1;
 			else