diff --git a/drivers/st/scmi-msg/base.h b/drivers/st/scmi-msg/base.h
new file mode 100644
index 0000000..c4a9c64
--- /dev/null
+++ b/drivers/st/scmi-msg/base.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019-2020, Linaro Limited
+ */
+
+#ifndef SCMI_MSG_BASE_H
+#define SCMI_MSG_BASE_H
+
+#include <stdint.h>
+
+#define SCMI_PROTOCOL_VERSION_BASE	0x20000U
+
+#define SCMI_DEFAULT_STRING_LENGTH	16U
+
+enum scmi_base_message_id {
+	SCMI_BASE_DISCOVER_VENDOR			= 0x003,
+	SCMI_BASE_DISCOVER_SUB_VENDOR			= 0x004,
+	SCMI_BASE_DISCOVER_IMPLEMENTATION_VERSION	= 0x005,
+	SCMI_BASE_DISCOVER_LIST_PROTOCOLS		= 0x006,
+	SCMI_BASE_DISCOVER_AGENT			= 0x007,
+	SCMI_BASE_NOTIFY_ERRORS				= 0x008,
+};
+
+/*
+ * PROTOCOL_ATTRIBUTES
+ */
+
+#define SCMI_BASE_PROTOCOL_ATTRS_NUM_PROTOCOLS_POS	0
+#define SCMI_BASE_PROTOCOL_ATTRS_NUM_AGENTS_POS		8
+
+#define SCMI_BASE_PROTOCOL_ATTRS_NUM_PROTOCOLS_MASK	0xFFU
+#define SCMI_BASE_PROTOCOL_ATTRS_NUM_AGENTS_MASK	0xFF00U
+
+#define SCMI_BASE_PROTOCOL_ATTRIBUTES(NUM_PROTOCOLS, NUM_AGENTS) \
+	((((NUM_PROTOCOLS) << SCMI_BASE_PROTOCOL_ATTRS_NUM_PROTOCOLS_POS) & \
+	  SCMI_BASE_PROTOCOL_ATTRS_NUM_PROTOCOLS_MASK) | \
+	(((NUM_AGENTS) << SCMI_BASE_PROTOCOL_ATTRS_NUM_AGENTS_POS) & \
+	 SCMI_BASE_PROTOCOL_ATTRS_NUM_AGENTS_MASK))
+
+/*
+ * BASE_DISCOVER_VENDOR
+ */
+struct scmi_base_discover_vendor_p2a {
+	int32_t status;
+	char vendor_identifier[SCMI_DEFAULT_STRING_LENGTH];
+};
+
+/*
+ * BASE_DISCOVER_SUB_VENDOR
+ */
+struct scmi_base_discover_sub_vendor_p2a {
+	int32_t status;
+	char sub_vendor_identifier[SCMI_DEFAULT_STRING_LENGTH];
+};
+
+/*
+ * BASE_DISCOVER_IMPLEMENTATION_VERSION
+ * No special structure right now, see protocol_version.
+ */
+
+/*
+ * BASE_DISCOVER_LIST_PROTOCOLS
+ */
+struct scmi_base_discover_list_protocols_a2p {
+	uint32_t skip;
+};
+
+struct scmi_base_discover_list_protocols_p2a {
+	int32_t status;
+	uint32_t num_protocols;
+	uint32_t protocols[];
+};
+
+#endif /* SCMI_MSG_BASE_H */