diff --git a/firmware/ice40-riscv/e1-tracer/misc.h b/firmware/ice40-riscv/e1-tracer/misc.h
new file mode 100644
index 0000000..31e8f80
--- /dev/null
+++ b/firmware/ice40-riscv/e1-tracer/misc.h
@@ -0,0 +1,15 @@
+/*
+ * misc.h
+ *
+ * Copyright (C) 2019-2020  Sylvain Munaut <tnt@246tNt.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+void vio_set(unsigned value);
+
+void e1_tick_read(uint16_t *ticks);