diff --git a/services/std_svc/drtm/drtm_main.h b/services/std_svc/drtm/drtm_main.h
new file mode 100644
index 0000000..39c67ce
--- /dev/null
+++ b/services/std_svc/drtm/drtm_main.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2022 Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier:    BSD-3-Clause
+ *
+ */
+#ifndef DRTM_MAIN_H
+#define DRTM_MAIN_H
+
+#include <stdint.h>
+
+#include <lib/smccc.h>
+
+enum drtm_retc {
+	SUCCESS = SMC_OK,
+	NOT_SUPPORTED = SMC_UNK,
+	INVALID_PARAMETERS = -2,
+	DENIED = -3,
+	NOT_FOUND = -4,
+	INTERNAL_ERROR = -5,
+	MEM_PROTECT_INVALID = -6,
+};
+
+#endif /* DRTM_MAIN_H */