diff --git a/include/lib/aarch32/arch.h b/include/lib/aarch32/arch.h
index 53ef4ba..6f41db9 100644
--- a/include/lib/aarch32/arch.h
+++ b/include/lib/aarch32/arch.h
@@ -20,6 +20,8 @@
 #define MIDR_REV_BITS		U(4)
 #define MIDR_PN_MASK		U(0xfff)
 #define MIDR_PN_SHIFT		U(4)
+#define MIDR_VAR_MASK		U(0xf0)
+#define MIDR_REV_MASK		U(0xf)
 
 /*******************************************************************************
  * MPIDR macros
diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index 0e2903e..f3ff0ca 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -16,7 +16,7 @@
 #define MIDR_IMPL_SHIFT		U(0x18)
 #define MIDR_VAR_SHIFT		U(20)
 #define MIDR_VAR_BITS		U(4)
-#define MIDR_VAR_MASK		U(0xf)
+#define MIDR_VAR_MASK		U(0xf0)
 #define MIDR_REV_SHIFT		U(0)
 #define MIDR_REV_BITS		U(4)
 #define MIDR_REV_MASK		U(0xf)
diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index 7c3ffc5..b7c0418 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -397,6 +397,8 @@
 #define clr_cntp_ctl_enable(x)  ((x) &= ~(U(1) << CNTP_CTL_ENABLE_SHIFT))
 #define clr_cntp_ctl_imask(x)   ((x) &= ~(U(1) << CNTP_CTL_IMASK_SHIFT))
 
+#define read_midr()		read_midr_el1()
+
 DEFINE_SYSREG_RW_FUNCS(tpidr_el3)
 
 DEFINE_SYSREG_RW_FUNCS(cntvoff_el2)
diff --git a/include/runtime_services/errata_abi.h b/include/runtime_services/errata_abi.h
new file mode 100644
index 0000000..363564e
--- /dev/null
+++ b/include/runtime_services/errata_abi.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2023, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * Definitions related to the Errata ABI feature
+ * as per the SMC Calling Convention.
+ */
+
+#ifndef __ERRATA_ABI_H__
+#define __ERRATA_ABI_H__
+
+#ifndef __ASSEMBLY__
+#include <stdbool.h>
+#include <stdint.h>
+#include <tftf_lib.h>
+#include <platform_def.h>
+#endif
+
+/*******************************************************************************
+ * Macro to create the array entry for EM_ABI_functions[]
+ ******************************************************************************/
+#define DEFINE_EM_FUNC(_func_id, _mandatory) \
+	{  EM_##_func_id, _mandatory, "SMC_" # _func_id }
+
+/*******************************************************************************
+ * Errata ABI feature supported function ids
+ ******************************************************************************/
+#define EM_VERSION		0x840000F0
+#define EM_FEATURES		0x840000F1
+#define EM_CPU_ERRATUM_FEATURES	0x840000F2
+
+/*
+ * Number of EM ABI calls defined in the specification.
+ */
+#define TOTAL_ABI_CALLS		(3U)
+
+#define ERRATA_COUNT		(17U)
+
+typedef struct {
+	uint32_t id;
+	bool mandatory;
+	const char *str;
+} em_function_t;
+
+typedef struct em_cpu_errata {
+	int em_errata_id;
+	unsigned int rxpx_low;
+	unsigned int rxpx_high;
+} em_cpu_errata_t;
+
+typedef struct em_cpu{
+	uint16_t cpu_pn;
+	em_cpu_errata_t cpu_errata[ERRATA_COUNT];
+}em_cpu_t;
+
+extern const em_function_t em_functions[TOTAL_ABI_CALLS];
+int32_t tftf_em_abi_version(void);
+bool tftf_em_abi_feature_implemented(uint32_t id);
+smc_ret_values tftf_em_abi_cpu_feature_implemented(uint32_t cpu_erratum, uint32_t forward_flag);
+
+
+#define IN_RANGE(x, y, z)		(((x >= y) && (x <= z)) ? true : false)
+
+/*******************************************************************************
+ * Errata ABI Version
+ ******************************************************************************/
+#define EM_MAJOR_VER_SHIFT	(16)
+#define EM_MAJOR_VER_MASK	(0xFFFF)
+#define EM_MINOR_VER_SHIFT	(0)
+#define EM_MINOR_VER_MASK	(0xFFFF)
+#define EM_ABI_VERSION(major, minor)	(((major & EM_MAJOR_VER_MASK) << EM_MAJOR_VER_SHIFT) \
+					| ((minor & EM_MINOR_VER_MASK) << EM_MINOR_VER_SHIFT))
+/*******************************************************************************
+ * Error codes
+ ******************************************************************************/
+#define EM_HIGHER_EL_MITIGATION		(3)
+#define EM_NOT_AFFECTED			(2)
+#define EM_AFFECTED			(1)
+#define EM_SUCCESS			(0)
+#define EM_NOT_SUPPORTED		(-1)
+#define EM_INVALID_PARAMETERS		(-2)
+#define EM_UNKNOWN_ERRATUM		(-3)
+#endif /* __ERRATA_ABI_H__ */
+