diff --git a/board/sophgo/milkv_duo/ethernet.h b/board/sophgo/milkv_duo/ethernet.h
new file mode 100644
index 0000000..7b21f1b
--- /dev/null
+++ b/board/sophgo/milkv_duo/ethernet.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2024, Kongyang Liu <seashell11234455@gmail.com>
+ */
+
+#ifndef __CV1800B_ETHERNET_H
+#define __CV1800B_ETHERNET_H
+
+void cv1800b_ephy_init(void);
+
+#endif