diff --git a/include/common/ep_info.h b/include/common/ep_info.h
index 4bfa1fa..771572c 100644
--- a/include/common/ep_info.h
+++ b/include/common/ep_info.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2021, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -18,14 +18,21 @@
 
 #define SECURE		EP_SECURE
 #define NON_SECURE	EP_NON_SECURE
+#define REALM		EP_REALM
+#if ENABLE_RME
+#define sec_state_is_valid(s)	(((s) == SECURE) ||	\
+				((s) == NON_SECURE) ||	\
+				((s) == REALM))
+#else
 #define sec_state_is_valid(s) (((s) == SECURE) || ((s) == NON_SECURE))
+#endif
 
 #define PARAM_EP_SECURITY_MASK	EP_SECURITY_MASK
 
 #define NON_EXECUTABLE	EP_NON_EXECUTABLE
 #define EXECUTABLE	EP_EXECUTABLE
 
-/* Secure or Non-secure image */
+/* Get/set security state of an image */
 #define GET_SECURITY_STATE(x) ((x) & EP_SECURITY_MASK)
 #define SET_SECURITY_STATE(x, security) \
 			((x) = ((x) & ~EP_SECURITY_MASK) | (security))
diff --git a/include/export/common/ep_info_exp.h b/include/export/common/ep_info_exp.h
index 9d2969f..a5bd10a 100644
--- a/include/export/common/ep_info_exp.h
+++ b/include/export/common/ep_info_exp.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2021, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -24,11 +24,23 @@
 #define ENTRY_POINT_INFO_ARGS_OFFSET	U(0x14)
 #endif
 
-/* Security state of the image. */
-#define EP_SECURITY_MASK	UL(0x1)
+/*
+ * Security state of the image. Bit 0 and
+ * bit 5 are used to determine the security
+ * state of the image as follows:
+ *
+ * ---------------------------------
+ *  Bit 5 | Bit 0 | Security state
+ * ---------------------------------
+ *   0        0      EP_SECURE
+ *   0        1      EP_NON_SECURE
+ *   1        1      EP_REALM
+ */
+#define EP_SECURITY_MASK	UL(0x21)
 #define EP_SECURITY_SHIFT	UL(0)
 #define EP_SECURE		UL(0x0)
 #define EP_NON_SECURE		UL(0x1)
+#define EP_REALM		UL(0x21)
 
 /* Endianness of the image. */
 #define EP_EE_MASK		U(0x2)
diff --git a/include/lib/smccc.h b/include/lib/smccc.h
index deaeb1d..1a39f24 100644
--- a/include/lib/smccc.h
+++ b/include/lib/smccc.h
@@ -108,9 +108,24 @@
 #define SMC_ARCH_CALL_NOT_REQUIRED	-2
 #define SMC_ARCH_CALL_INVAL_PARAM	-3
 
-/* Various flags passed to SMC handlers */
+/*
+ * Various flags passed to SMC handlers
+ *
+ * Bit 5 and bit 0 of the flag are used to
+ * determine the source security state as
+ * follows:
+ * ---------------------------------
+ *  Bit 5 | Bit 0 | Security state
+ * ---------------------------------
+ *   0        0      SMC_FROM_SECURE
+ *   0        1      SMC_FROM_NON_SECURE
+ *   1        1      SMC_FROM_REALM
+ */
+
 #define SMC_FROM_SECURE		(U(0) << 0)
 #define SMC_FROM_NON_SECURE	(U(1) << 0)
+#define SMC_FROM_REALM		U(0x21)
+#define SMC_FROM_MASK		U(0x21)
 
 #ifndef __ASSEMBLER__
 
@@ -118,8 +133,18 @@
 
 #include <lib/cassert.h>
 
+#if ENABLE_RME
+#define is_caller_non_secure(_f)	(((_f) & SMC_FROM_MASK) \
+					  == SMC_FROM_NON_SECURE)
+#define is_caller_secure(_f)		(((_f) & SMC_FROM_MASK) \
+					  == SMC_FROM_SECURE)
+#define is_caller_realm(_f)		(((_f) & SMC_FROM_MASK) \
+					  == SMC_FROM_REALM)
+#define caller_sec_state(_f)		((_f) & SMC_FROM_MASK)
+#else /* ENABLE_RME */
 #define is_caller_non_secure(_f)	(((_f) & SMC_FROM_NON_SECURE) != U(0))
 #define is_caller_secure(_f)		(!is_caller_non_secure(_f))
+#endif /* ENABLE_RME */
 
 /* The macro below is used to identify a Standard Service SMC call */
 #define is_std_svc_call(_fid)		(GET_SMC_OEN(_fid) == OEN_STD_START)