Merge changes from topic "jc/detect_feat" into integration

* changes: docs(build): update the feature enablement flags refactor(el3-runtime): replace ARM_ARCH_AT_LEAST macro with FEAT flags refactor(el3-runtime): add arch-features detection mechanism
2022-04-07 15:19:04 +02:00 · 2022-04-07 15:19:04 +02:00 · f6ca81ddfb
parent fe029b5829 d9e984cc30
commit f6ca81ddfb
12 changed files with 894 additions and 209 deletions
--- a/65
+++ b/65
@ -263,24 +263,6 @@ ENABLE_FEAT_RNG		=	$(if $(findstring rng,${arch-features}),1,0)
 # Determine if FEAT_SB is supported
 ENABLE_FEAT_SB		=	$(if $(findstring sb,${arch-features}),1,0)

-ifeq "8.5" "$(word 1, $(sort 8.5 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
-ENABLE_FEAT_SB		= 	1
-endif
-
-# Determine and enable FEAT_FGT to access HDFGRTR_EL2 register for v8.6 and higher versions.
-ifeq "8.6" "$(word 1, $(sort 8.6 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
-ENABLE_FEAT_FGT		=	1
-endif
-
-# Determine and enable FEAT_ECV to access CNTPOFF_EL2 register for v8.6 and higher versions.
-ifeq "8.6" "$(word 1, $(sort 8.6 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
-ENABLE_FEAT_ECV		=	1
-endif
-
-ifeq "8.4" "$(word 1, $(sort 8.4 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
-ENABLE_FEAT_DIT		= 	1
-endif
-
 ifneq ($(findstring armclang,$(notdir $(CC))),)
 TF_CFLAGS_aarch32	=	-target arm-arm-none-eabi $(march32-directive)
 TF_CFLAGS_aarch64	=	-target aarch64-arm-none-eabi $(march64-directive)
@ -474,6 +456,7 @@ endif
 ################################################################################
 # Common sources and include directories
 ################################################################################
+include ${MAKE_HELPERS_DIRECTORY}arch_features.mk
 include lib/compiler-rt/compiler-rt.mk

 BL_COMMON_SOURCES	+=	common/bl_common.c			\
@ -776,6 +759,10 @@ ifeq ($(PSA_FWU_SUPPORT),1)
    $(info PSA_FWU_SUPPORT is an experimental feature)
 endif

+ifeq ($(FEATURE_DETECTION),1)
+    $(info FEATURE_DETECTION is an experimental feature)
+endif
+
 ifeq (${ARM_XLAT_TABLES_LIB_V1}, 1)
    ifeq (${ALLOW_RO_XLAT_TABLES}, 1)
        $(error "ALLOW_RO_XLAT_TABLES requires translation tables library v2")
@ -980,10 +967,7 @@ $(eval $(call assert_booleans,\
        CREATE_KEYS \
        CTX_INCLUDE_AARCH32_REGS \
        CTX_INCLUDE_FPREGS \
-        CTX_INCLUDE_PAUTH_REGS \
-        CTX_INCLUDE_MTE_REGS \
        CTX_INCLUDE_EL2_REGS \
-        CTX_INCLUDE_NEVE_REGS \
        DEBUG \
        DISABLE_MTPMU \
        DYN_DISABLE_AUTH \
@ -993,11 +977,9 @@ $(eval $(call assert_booleans,\
        ENABLE_AMU_FCONF \
        AMU_RESTRICT_COUNTERS \
        ENABLE_ASSERTIONS \
-        ENABLE_MPAM_FOR_LOWER_ELS \
        ENABLE_PIE \
        ENABLE_PMF \
        ENABLE_PSCI_STAT \
-        ENABLE_RME \
        ENABLE_RUNTIME_INSTRUMENTATION \
        ENABLE_SME_FOR_NS \
        ENABLE_SME_FOR_SWD \
@ -1017,7 +999,6 @@ $(eval $(call assert_booleans,\
        PL011_GENERIC_UART \
        PROGRAMMABLE_RESET_ADDRESS \
        PSCI_EXTENDED_STATE_ID \
-        RAS_EXTENSION \
        RESET_TO_BL31 \
        SAVE_KEYS \
        SEPARATE_CODE_AND_RODATA \
@ -1046,20 +1027,13 @@ $(eval $(call assert_booleans,\
        RAS_TRAP_LOWER_EL_ERR_ACCESS \
        COT_DESC_IN_DTB \
        USE_SP804_TIMER \
-        ENABLE_FEAT_RNG \
-        ENABLE_FEAT_SB \
-        ENABLE_FEAT_DIT \
        PSA_FWU_SUPPORT \
        ENABLE_TRBE_FOR_NS \
        ENABLE_SYS_REG_TRACE_FOR_NS \
-        ENABLE_TRF_FOR_NS \
-        ENABLE_FEAT_HCX \
        ENABLE_MPMM \
        ENABLE_MPMM_FCONF \
-        ENABLE_FEAT_FGT \
-        ENABLE_FEAT_AMUv1 \
-        ENABLE_FEAT_ECV \
        SIMICS_BUILD \
+        FEATURE_DETECTION \
 )))

 $(eval $(call assert_numerics,\
@ -1067,9 +1041,30 @@ $(eval $(call assert_numerics,\
        ARM_ARCH_MAJOR \
        ARM_ARCH_MINOR \
        BRANCH_PROTECTION \
+        CTX_INCLUDE_PAUTH_REGS \
+        CTX_INCLUDE_MTE_REGS \
+        CTX_INCLUDE_NEVE_REGS \
+        ENABLE_BTI \
+        ENABLE_PAUTH \
+        ENABLE_FEAT_AMUv1 \
+        ENABLE_FEAT_AMUv1p1 \
+        ENABLE_FEAT_CSV2_2 \
+        ENABLE_FEAT_DIT \
+        ENABLE_FEAT_ECV \
+        ENABLE_FEAT_FGT \
+        ENABLE_FEAT_HCX \
+        ENABLE_FEAT_PAN \
+        ENABLE_FEAT_RNG \
+        ENABLE_FEAT_SB \
+        ENABLE_FEAT_SEL2 \
+        ENABLE_FEAT_VHE \
+        ENABLE_MPAM_FOR_LOWER_ELS \
+        ENABLE_RME \
+        ENABLE_TRF_FOR_NS \
        FW_ENC_STATUS \
        NR_OF_FW_BANKS \
        NR_OF_IMAGES_IN_FW_BANK \
+        RAS_EXTENSION \
 )))

 ifdef KEY_SIZE
@ -1179,6 +1174,12 @@ $(eval $(call add_defines,\
        ENABLE_FEAT_AMUv1 \
        ENABLE_FEAT_ECV \
        SIMICS_BUILD \
+        ENABLE_FEAT_AMUv1p1 \
+        ENABLE_FEAT_SEL2 \
+        ENABLE_FEAT_VHE \
+        ENABLE_FEAT_CSV2_2 \
+        ENABLE_FEAT_PAN \
+        FEATURE_DETECTION \
 )))

 ifeq (${SANITIZE_UB},trap)
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@ -128,6 +128,10 @@ BL31_SOURCES		+=	${GPT_LIB_SRCS}					\
 				${RMMD_SOURCES}
 endif

+ifeq ($(FEATURE_DETECTION),1)
+BL31_SOURCES		+=	common/feat_detect.c
+endif
+
 BL31_LINKERFILE		:=	bl31/bl31.ld.S

 # Flag used to indicate if Crash reporting via console should be included
--- a/bl31/bl31_main.c
+++ b/bl31/bl31_main.c
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
@ -14,6 +14,7 @@
 #include <bl31/ehf.h>
 #include <common/bl_common.h>
 #include <common/debug.h>
+#include <common/feat_detect.h>
 #include <common/runtime_svc.h>
 #include <drivers/console.h>
 #include <lib/el3_runtime/context_mgmt.h>
@ -123,6 +124,11 @@ void bl31_main(void)
 	NOTICE("BL31: %s\n", version_string);
 	NOTICE("BL31: %s\n", build_message);

+#if FEATURE_DETECTION
+	/* Detect if features enabled during compilation are supported by PE. */
+	detect_arch_features();
+#endif /* FEATURE_DETECTION */
+
 #ifdef SUPPORT_UNKNOWN_MPID
 	if (unsupported_mpid_flag == 0) {
 		NOTICE("Unsupported MPID detected!\n");
--- a/common/feat_detect.c
+++ b/common/feat_detect.c
@ -0,0 +1,288 @@
+/*
+ * Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/feat_detect.h>
+
+/*******************************************************************************
+ * This section lists the wrapper modules for each feature to evaluate the
+ * feature states (FEAT_STATE_1 and FEAT_STATE_2) and perform necessary action
+ * as below:
+ *
+ * It verifies whether the FEAT_XXX (eg: FEAT_SB) is supported by the PE or not.
+ * Without this check an exception would occur during context save/restore
+ * routines, if the feature is enabled but not supported by PE.
+ ******************************************************************************/
+
+/******************************************
+ * Feature : FEAT_SB (Speculation Barrier)
+ *****************************************/
+static void read_feat_sb(void)
+{
+#if (ENABLE_FEAT_SB == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_0_feat_sb_present(), "SB");
+#endif
+}
+
+/******************************************************
+ * Feature : FEAT_CSV2_2 (Cache Speculation Variant 2)
+ *****************************************************/
+static void read_feat_csv2_2(void)
+{
+#if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_0_feat_csv2_2_present(), "CSV2_2");
+#endif
+}
+
+/***********************************************
+ * Feature : FEAT_PAN (Privileged Access Never)
+ **********************************************/
+static void read_feat_pan(void)
+{
+#if (ENABLE_FEAT_PAN == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_1_pan_present(), "PAN");
+#endif
+}
+
+/******************************************************
+ * Feature : FEAT_VHE (Virtualization Host Extensions)
+ *****************************************************/
+static void read_feat_vhe(void)
+{
+#if (ENABLE_FEAT_VHE == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_1_vhe_present(), "VHE");
+#endif
+}
+
+/*******************************************************************************
+ * Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension)
+ ******************************************************************************/
+static void read_feat_ras(void)
+{
+#if (RAS_EXTENSION == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_2_feat_ras_present(), "RAS");
+#endif
+}
+
+/************************************************
+ * Feature : FEAT_PAUTH (Pointer Authentication)
+ ***********************************************/
+static void read_feat_pauth(void)
+{
+#if (ENABLE_PAUTH == FEAT_STATE_1) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH");
+#endif
+}
+
+/************************************************************
+ * Feature : FEAT_DIT (Data Independent Timing Instructions)
+ ***********************************************************/
+static void read_feat_dit(void)
+{
+#if (ENABLE_FEAT_DIT == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT");
+#endif
+}
+
+/*********************************************************
+ * Feature : FEAT_AMUv1 (Activity Monitors Extensions v1)
+ ********************************************************/
+static void read_feat_amuv1(void)
+{
+#if (ENABLE_FEAT_AMUv1 == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_4_feat_amuv1_present(), "AMUv1");
+#endif
+}
+
+/****************************************************************************
+ * Feature : FEAT_MPAM (Memory Partitioning and Monitoring (MPAM) Extension)
+ ***************************************************************************/
+static void read_feat_mpam(void)
+{
+#if (ENABLE_MPAM_FOR_LOWER_ELS == FEAT_STATE_1)
+	feat_detect_panic(get_mpam_version() != 0U, "MPAM");
+#endif
+}
+
+/**************************************************************
+ * Feature : FEAT_NV2 (Enhanced Nested Virtualization Support)
+ *************************************************************/
+static void read_feat_nv2(void)
+{
+#if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_1)
+	unsigned int nv = get_armv8_4_feat_nv_support();
+
+	feat_detect_panic((nv == ID_AA64MMFR2_EL1_NV2_SUPPORTED), "NV2");
+#endif
+}
+
+/***********************************
+ * Feature : FEAT_SEL2 (Secure EL2)
+ **********************************/
+static void read_feat_sel2(void)
+{
+#if (ENABLE_FEAT_SEL2 == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_4_sel2_present(), "SEL2");
+#endif
+}
+
+/****************************************************
+ * Feature : FEAT_TRF (Self-hosted Trace Extensions)
+ ***************************************************/
+static void read_feat_trf(void)
+{
+#if (ENABLE_TRF_FOR_NS == FEAT_STATE_1)
+	feat_detect_panic(is_arm8_4_feat_trf_present(), "TRF");
+#endif
+}
+
+/************************************************
+ * Feature : FEAT_MTE (Memory Tagging Extension)
+ ***********************************************/
+static void read_feat_mte(void)
+{
+#if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_1)
+	unsigned int mte = get_armv8_5_mte_support();
+
+	feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE");
+#endif
+}
+
+/***********************************************
+ * Feature : FEAT_RNG (Random Number Generator)
+ **********************************************/
+static void read_feat_rng(void)
+{
+#if (ENABLE_FEAT_RNG == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_5_rng_present(), "RNG");
+#endif
+}
+
+/****************************************************
+ * Feature : FEAT_BTI (Branch Target Identification)
+ ***************************************************/
+static void read_feat_bti(void)
+{
+#if (ENABLE_BTI == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_5_bti_present(), "BTI");
+#endif
+}
+
+/****************************************
+ * Feature : FEAT_FGT (Fine Grain Traps)
+ ***************************************/
+static void read_feat_fgt(void)
+{
+#if (ENABLE_FEAT_FGT == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_6_fgt_present(), "FGT");
+#endif
+}
+
+/***********************************************
+ * Feature : FEAT_AMUv1p1 (AMU Extensions v1.1)
+ **********************************************/
+static void read_feat_amuv1p1(void)
+{
+#if (ENABLE_FEAT_AMUv1p1 == FEAT_STATE_1)
+	feat_detect_panic(is_armv8_6_feat_amuv1p1_present(), "AMUv1p1");
+#endif
+}
+
+/*******************************************************
+ * Feature : FEAT_ECV (Enhanced Counter Virtualization)
+ ******************************************************/
+static void read_feat_ecv(void)
+{
+#if (ENABLE_FEAT_ECV == FEAT_STATE_1)
+	unsigned int ecv = get_armv8_6_ecv_support();
+
+	feat_detect_panic(((ecv == ID_AA64MMFR0_EL1_ECV_SUPPORTED) ||
+			(ecv == ID_AA64MMFR0_EL1_ECV_SELF_SYNCH)), "ECV");
+#endif
+}
+
+/******************************************************************
+ * Feature : FEAT_HCX (Extended Hypervisor Configuration Register)
+ *****************************************************************/
+static void read_feat_hcx(void)
+{
+#if (ENABLE_FEAT_HCX == FEAT_STATE_1)
+	feat_detect_panic(is_feat_hcx_present(), "HCX");
+#endif
+}
+
+/**************************************************
+ * Feature : FEAT_RME (Realm Management Extension)
+ *************************************************/
+static void read_feat_rme(void)
+{
+#if (ENABLE_RME == FEAT_STATE_1)
+	feat_detect_panic((get_armv9_2_feat_rme_support() !=
+			ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME");
+#endif
+}
+
+/***********************************************************************************
+ * TF-A supports many Arm architectural features starting from arch version
+ * (8.0 till 8.7+). These features are mostly enabled through build flags. This
+ * mechanism helps in validating these build flags in the early boot phase
+ * either in BL1 or BL31 depending on the platform and assists in identifying
+ * and notifying the features which are enabled but not supported by the PE.
+ *
+ * It reads all the enabled features ID-registers and ensures the features
+ * are supported by the PE.
+ * In case if they aren't it stops booting at an early phase and logs the error
+ * messages, notifying the platforms about the features that are not supported.
+ *
+ * Further the procedure is implemented with a tri-state approach for each feature:
+ * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time
+ * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware.
+ *                       There will be panic if feature is not present at cold boot.
+ * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime
+ *                       depending on hardware capability.
+ *
+ * For better readability, state values are defined with macros namely:
+ * { FEAT_STATE_0, FEAT_STATE_1, FEAT_STATE_2 } taking values as their naming.
+ **********************************************************************************/
+void detect_arch_features(void)
+{
+	/* v8.0 features */
+	read_feat_sb();
+	read_feat_csv2_2();
+
+	/* v8.1 features */
+	read_feat_pan();
+	read_feat_vhe();
+
+	/* v8.2 features */
+	read_feat_ras();
+
+	/* v8.3 features */
+	read_feat_pauth();
+
+	/* v8.4 features */
+	read_feat_dit();
+	read_feat_amuv1();
+	read_feat_mpam();
+	read_feat_nv2();
+	read_feat_sel2();
+	read_feat_trf();
+
+	/* v8.5 features */
+	read_feat_mte();
+	read_feat_rng();
+	read_feat_bti();
+
+	/* v8.6 features */
+	read_feat_amuv1p1();
+	read_feat_fgt();
+	read_feat_ecv();
+
+	/* v8.7 features */
+	read_feat_hcx();
+
+	/* v9.2 features */
+	read_feat_rme();
+}
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@ -174,14 +174,23 @@ Common build options
   registers to be included when saving and restoring the CPU context. Default
   is 0.

-  ``CTX_INCLUDE_NEVE_REGS``: Boolean option that, when set to 1, will cause the
-   Armv8.4-NV registers to be saved/restored when entering/exiting an EL2
-   execution context. Default value is 0.
+-  ``CTX_INCLUDE_MTE_REGS``: Numeric value to include Memory Tagging Extension
+   registers in cpu context. This must be enabled, if the platform wants to use
+   this feature in the Secure world and MTE is enabled at ELX. This flag can
+   take values 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
+   Default value is 0.
+
+-  ``CTX_INCLUDE_NEVE_REGS``: Numeric value, when set will cause the Armv8.4-NV
+   registers to be saved/restored when entering/exiting an EL2 execution
+   context. This flag can take values 0 to 2, to align with the
+   ``FEATURE_DETECTION`` mechanism. Default value is 0.
+
+-  ``CTX_INCLUDE_PAUTH_REGS``: Numeric value to enable the Pointer
+   Authentication for Secure world. This will cause the ARMv8.3-PAuth registers
+   to be included when saving and restoring the CPU context as part of world
+   switch. This flag can take values 0 to 2, to align with ``FEATURE_DETECTION``
+   mechanism. Default value is 0.

-  ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, enables
-   Pointer Authentication for Secure world. This will cause the ARMv8.3-PAuth
-   registers to be included when saving and restoring the CPU context as
-   part of world switch. Default value is 0.
   Note that Pointer Authentication is enabled for Non-secure world irrespective
   of the value of this flag if the CPU supports it.

@ -246,42 +255,101 @@ Common build options
   builds, but this behaviour can be overridden in each platform's Makefile or
   in the build command line.

-  ``ENABLE_FEAT_AMUv1``: Boolean option to enable access to the HAFGRTR_EL2
+-  ``ENABLE_FEAT_AMUv1``: Numeric value to enable access to the HAFGRTR_EL2
   (Hypervisor Activity Monitors Fine-Grained Read Trap Register) during EL2
-   to EL3 context save/restore operations. It is an optional feature available
-   on v8.4 and onwards and must be set to 1 alongside ``ENABLE_FEAT_FGT``, to
-   access the HAFGRTR_EL2 register. Defaults to ``0``.
+   to EL3 context save/restore operations. This flag can take the values 0 to 2,
+   to align with the ``FEATURE_DETECTION`` mechanism. It is an optional feature
+   available on v8.4 and onwards and must be set to either 1 or 2 alongside
+   ``ENABLE_FEAT_FGT``, to access the HAFGRTR_EL2 register.
+   Default value is ``0``.

-  ``ENABLE_FEAT_ECV``: Boolean option to enable support for the Enhanced Counter
+-  ``ENABLE_FEAT_AMUv1p1``: Numeric value to enable the ``FEAT_AMUv1p1``
+   extension. ``FEAT_AMUv1p1`` is an optional feature available on Arm v8.6
+   onwards. This flag can take the values 0 to 2, to align with the
+   ``FEATURE_DETECTION`` mechanism. Default value is ``0``.
+
+-  ``ENABLE_FEAT_CSV2_2``: Numeric value to enable the ``FEAT_CSV2_2``
+   extension. It allows access to the SCXTNUM_EL2 (Software Context Number)
+   register during EL2 context save/restore operations. ``FEAT_CSV2_2`` is an
+   optional feature available on Arm v8.0 onwards. This flag can take values
+   0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
+   Default value is ``0``.
+
+-  ``ENABLE_FEAT_DIT``: Numeric value to enable ``FEAT_DIT`` (Data Independent
+   Timing) extension. It allows setting the ``DIT`` bit of PSTATE in EL3.
+   ``FEAT_DIT`` is a mandatory  architectural feature and is enabled from v8.4
+   and upwards. This flag can take the values 0 to 2, to align  with the
+   ``FEATURE_DETECTION`` mechanism. Default value is ``0``.
+
+-  ``ENABLE_FEAT_ECV``: Numeric value to enable support for the Enhanced Counter
   Virtualization feature, allowing for access to the CNTPOFF_EL2 (Counter-timer
   Physical Offset register) during EL2 to EL3 context save/restore operations.
-   Its a mandatory architectural feature in Armv8.6 and defaults to ``1`` for
-   v8.6 or later CPUs.
+   Its a mandatory architectural feature and is enabled from v8.6 and upwards.
+   This flag can take the values 0 to 2, to align  with the ``FEATURE_DETECTION``
+   mechanism. Default value is ``0``.

-  ``ENABLE_FEAT_FGT``: Boolean option to enable support for FGT (Fine Grain Traps)
+-  ``ENABLE_FEAT_FGT``: Numeric value to enable support for FGT (Fine Grain Traps)
   feature allowing for access to the HDFGRTR_EL2 (Hypervisor Debug Fine-Grained
-   Read Trap Register)  during EL2 to EL3 context save/restore operations.
-   Its a mandatory architectural feature in Armv8.6 and defaults to ``1`` for
-   v8.6 or later CPUs.
+   Read Trap Register) during EL2 to EL3 context save/restore operations.
+   Its a mandatory architectural feature and is enabled from v8.6 and upwards.
+   This flag can take the values 0 to 2, to align  with the ``FEATURE_DETECTION``
+   mechanism. Default value is ``0``.

-  ``ENABLE_FEAT_HCX``: This option sets the bit SCR_EL3.HXEn in EL3 to allow
-   access to HCRX_EL2 (extended hypervisor control register) from EL2 as well as
-   adding HCRX_EL2 to the EL2 context save/restore operations.
+-  ``ENABLE_FEAT_HCX``: Numeric value to set the bit SCR_EL3.HXEn in EL3 to
+   allow access to HCRX_EL2 (extended hypervisor control register) from EL2 as
+   well as adding HCRX_EL2 to the EL2 context save/restore operations. Its a
+   mandatory architectural feature and is enabled from v8.7 and upwards. This
+   flag can take the values 0 to 2, to align  with the ``FEATURE_DETECTION``
+   mechanism. Default value is ``0``.
+
+-  ``ENABLE_FEAT_PAN``: Numeric value to enable the ``FEAT_PAN`` (Privileged
+   Access Never) extension. ``FEAT_PAN`` adds a bit to PSTATE, generating a
+   permission fault for any privileged data access from EL1/EL2 to virtual
+   memory address, accessible at EL0, provided (HCR_EL2.E2H=1). It is a
+   mandatory architectural feature and is enabled from v8.1 and upwards. This
+   flag can take values 0 to 2, to align  with the ``FEATURE_DETECTION``
+   mechanism. Default value is ``0``.
+
+-  ``ENABLE_FEAT_RNG``: Numeric value to enable the ``FEAT_RNG`` extension.
+   ``FEAT_RNG`` is an optional feature available on Arm v8.5 onwards. This
+   flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
+   mechanism. Default is ``0``.
+
+-  ``ENABLE_FEAT_SB``: Numeric value to enable the ``FEAT_SB`` (Speculation
+   Barrier) extension allowing access to ``sb`` instruction. ``FEAT_SB`` is an
+   optional feature and defaults to ``0`` for pre-Armv8.5 CPUs but are mandatory
+   for Armv8.5 or later CPUs. This flag can take values 0 to 2, to align with
+   ``FEATURE_DETECTION`` mechanism. It is enabled from v8.5 and upwards and if
+   needed could be overidden from platforms explicitly. Default value is ``0``.
+
+-  ``ENABLE_FEAT_SEL2``: Numeric value to enable the ``FEAT_SEL2`` (Secure EL2)
+   extension. ``FEAT_SEL2`` is a mandatory feature available on Arm v8.4.
+   This flag can take values 0 to 2, to align with the ``FEATURE_DETECTION``
+   mechanism. Default is ``0``.
+
+-  ``ENABLE_FEAT_VHE``: Numeric value to enable the ``FEAT_VHE`` (Virtualization
+   Host Extensions) extension. It allows access to CONTEXTIDR_EL2 register
+   during EL2 context save/restore operations.``FEAT_VHE`` is a mandatory
+   architectural feature and is enabled from v8.1 and upwards. It can take
+   values 0 to 2, to align  with the ``FEATURE_DETECTION`` mechanism.
+   Default value is ``0``.

 -  ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO)
   support in GCC for TF-A. This option is currently only supported for
   AArch64. Default is 0.

-  ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM
+-  ``ENABLE_MPAM_FOR_LOWER_ELS``: Numeric value to enable lower ELs to use MPAM
   feature. MPAM is an optional Armv8.4 extension that enables various memory
   system components and resources to define partitions; software running at
   various ELs can assign themselves to desired partition to control their
   performance aspects.

-   When this option is set to ``1``, EL3 allows lower ELs to access their own
-   MPAM registers without trapping into EL3. This option doesn't make use of
-   partitioning in EL3, however. Platform initialisation code should configure
-   and use partitions in EL3 as required. This option defaults to ``0``.
+   This flag can take values 0 to 2, to align  with the ``FEATURE_DETECTION``
+   mechanism. When this option is set to ``1`` or ``2``, EL3 allows lower ELs to
+   access their own MPAM registers without trapping into EL3. This option
+   doesn't make use of partitioning in EL3, however. Platform initialisation
+   code should configure and use partitions in EL3 as required. This option
+   defaults to ``0``.

 -  ``ENABLE_MPMM``: Boolean option to enable support for the Maximum Power
   Mitigation Mechanism supported by certain Arm cores, which allows the SoC
@ -307,9 +375,10 @@ Common build options
   be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in
   software.

- ``ENABLE_RME``: Boolean option to enable support for the ARMv9 Realm
-   Management Extension. Default value is 0. This is currently an experimental
-   feature.
+- ``ENABLE_RME``: Numeric value to enable support for the ARMv9 Realm
+   Management Extension. This flag can take the values 0 to 2, to align with
+   the ``FEATURE_DETECTION`` mechanism. Default value is 0. This is currently
+   an experimental feature.

 -  ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime
   instrumentation which injects timestamp collection points into TF-A to
@ -352,8 +421,8 @@ Common build options

 -  ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
   SVE is an optional architectural feature for AArch64. Note that this option
-   requires ENABLE_SVE_FOR_NS to be enabled.  The default is 0 and it is
-   automatically disabled when the target architecture is AArch32.
+   requires ENABLE_SVE_FOR_NS to be enabled. The default is 0 and it
+   is automatically disabled when the target architecture is AArch32.

 -  ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection
   checks in GCC. Allowed values are "all", "strong", "default" and "none". The
@ -399,6 +468,43 @@ Common build options
   This feature is intended for testing purposes only, and is advisable to keep
   disabled for production images.

+-  ``FEATURE_DETECTION``: Boolean option to enable the architectural features
+   detection mechanism. It detects whether the Architectural features enabled
+   through feature specific build flags are supported by the PE or not by
+   validating them either at boot phase or at runtime based on the value
+   possessed by the feature flag (0 to 2) and report error messages at an early
+   stage.
+
+   This prevents and benefits us from EL3 runtime exceptions during context save
+   and restore routines guarded by these build flags. Henceforth validating them
+   before their usage provides more control on the actions taken under them.
+
+   The mechanism permits the build flags to take values 0, 1 or 2 and
+   evaluates them accordingly.
+
+   Lets consider ``ENABLE_FEAT_HCX``, build flag for ``FEAT_HCX`` as an example:
+
+   ::
+
+     ENABLE_FEAT_HCX = 0: Feature disabled statically at compile time.
+     ENABLE_FEAT_HCX = 1: Feature Enabled and the flag is validated at boottime.
+     ENABLE_FEAT_HCX = 2: Feature Enabled and the flag is validated at runtime.
+
+   In the above example, if the feature build flag, ``ENABLE_FEAT_HCX`` set to
+   0, feature is disabled statically during compilation. If it is defined as 1,
+   feature is validated, wherein FEAT_HCX is detected at boot time. In case not
+   implemented by the PE, a hard panic is generated. Finally, if the flag is set
+   to 2, feature is validated at runtime.
+
+   Note that the entire implementation is divided into two phases, wherein as
+   as part of phase-1 we are supporting the values 0,1. Value 2 is currently not
+   supported and is planned to be handled explicilty in phase-2 implementation.
+
+   FEATURE_DETECTION macro is disabled by default, and is currently an
+   experimental procedure. Platforms can explicitly make use of this by
+   mechanism, by enabling it to validate whether they have set their build flags
+   properly at an early phase.
+
 -  ``FIP_NAME``: This is an optional build option which specifies the FIP
   filename for the ``fip`` target. Default is ``fip.bin``.

@ -588,9 +694,10 @@ Common build options
   enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be
   set to 1 as well.

-  ``RAS_EXTENSION``: When set to ``1``, enable Armv8.2 RAS features. RAS features
+-  ``RAS_EXTENSION``: Numeric value to enable Armv8.2 RAS features. RAS features
   are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2
-   or later CPUs.
+   or later CPUs. This flag can take the values 0 to 2, to align with the
+   ``FEATURE_DETECTION`` mechanism.

   When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be
   set to ``1``.
@ -673,7 +780,7 @@ Common build options
   firmware images have been loaded in memory, and the MMU and caches are
   turned off. Refer to the "Debugging options" section for more details.

-  ``SPMD_SPM_AT_SEL2`` : this boolean option is used jointly with the SPM
+-  ``SPMD_SPM_AT_SEL2`` : This boolean option is used jointly with the SPM
   Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC
   component runs at the S-EL2 execution state provided by the Armv8.4-SecEL2
   extension. This is the default when enabling the SPM Dispatcher. When
@ -851,9 +958,10 @@ Common build options
  but unused). This feature is available if trace unit such as ETMv4.x, and
  ETE(extending ETM feature) is implemented. This flag is disabled by default.

- ``ENABLE_TRF_FOR_NS``: Boolean option to enable trace filter control registers
+- ``ENABLE_TRF_FOR_NS``: Numeric value to enable trace filter control registers
  access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused),
-  if FEAT_TRF is implemented. This flag is disabled by default.
+  if FEAT_TRF is implemented. This flag can take the values 0 to 2, to align
+  with the ``FEATURE_DETECTION`` mechanism. This flag is disabled by default.

 GICv3 driver options
 --------------------
--- a/include/arch/aarch64/arch.h
+++ b/include/arch/aarch64/arch.h
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
 * Copyright (c) 2020, NVIDIA Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
@ -99,7 +99,6 @@
 /*******************************************************************************
 * Definitions for EL2 system registers for save/restore routine
 ******************************************************************************/
-
 #define CNTPOFF_EL2		S3_4_C14_C0_6
 #define HAFGRTR_EL2		S3_4_C3_C1_6
 #define HDFGRTR_EL2		S3_4_C3_C1_4
@ -155,39 +154,55 @@
 #endif

 /* ID_AA64PFR0_EL1 definitions */
-#define ID_AA64PFR0_EL0_SHIFT	U(0)
-#define ID_AA64PFR0_EL1_SHIFT	U(4)
-#define ID_AA64PFR0_EL2_SHIFT	U(8)
-#define ID_AA64PFR0_EL3_SHIFT	U(12)
-#define ID_AA64PFR0_AMU_SHIFT	U(44)
-#define ID_AA64PFR0_AMU_MASK	ULL(0xf)
-#define ID_AA64PFR0_AMU_NOT_SUPPORTED	U(0x0)
-#define ID_AA64PFR0_AMU_V1	U(0x1)
-#define ID_AA64PFR0_AMU_V1P1	U(0x2)
-#define ID_AA64PFR0_ELX_MASK	ULL(0xf)
-#define ID_AA64PFR0_GIC_SHIFT	U(24)
-#define ID_AA64PFR0_GIC_WIDTH	U(4)
-#define ID_AA64PFR0_GIC_MASK	ULL(0xf)
-#define ID_AA64PFR0_SVE_SHIFT	U(32)
-#define ID_AA64PFR0_SVE_MASK	ULL(0xf)
-#define ID_AA64PFR0_SVE_LENGTH	U(4)
-#define ID_AA64PFR0_SEL2_SHIFT	U(36)
-#define ID_AA64PFR0_SEL2_MASK	ULL(0xf)
-#define ID_AA64PFR0_MPAM_SHIFT	U(40)
-#define ID_AA64PFR0_MPAM_MASK	ULL(0xf)
-#define ID_AA64PFR0_DIT_SHIFT	U(48)
-#define ID_AA64PFR0_DIT_MASK	ULL(0xf)
-#define ID_AA64PFR0_DIT_LENGTH	U(4)
-#define ID_AA64PFR0_DIT_SUPPORTED	U(1)
-#define ID_AA64PFR0_CSV2_SHIFT	U(56)
-#define ID_AA64PFR0_CSV2_MASK	ULL(0xf)
-#define ID_AA64PFR0_CSV2_LENGTH	U(4)
+#define ID_AA64PFR0_EL0_SHIFT			U(0)
+#define ID_AA64PFR0_EL1_SHIFT			U(4)
+#define ID_AA64PFR0_EL2_SHIFT			U(8)
+#define ID_AA64PFR0_EL3_SHIFT			U(12)
+
+#define ID_AA64PFR0_AMU_SHIFT			U(44)
+#define ID_AA64PFR0_AMU_MASK			ULL(0xf)
+#define ID_AA64PFR0_AMU_NOT_SUPPORTED		U(0x0)
+#define ID_AA64PFR0_AMU_V1			ULL(0x1)
+#define ID_AA64PFR0_AMU_V1P1			U(0x2)
+
+#define ID_AA64PFR0_ELX_MASK			ULL(0xf)
+
+#define ID_AA64PFR0_GIC_SHIFT			U(24)
+#define ID_AA64PFR0_GIC_WIDTH			U(4)
+#define ID_AA64PFR0_GIC_MASK			ULL(0xf)
+
+#define ID_AA64PFR0_SVE_SHIFT			U(32)
+#define ID_AA64PFR0_SVE_MASK			ULL(0xf)
+#define ID_AA64PFR0_SVE_SUPPORTED		ULL(0x1)
+#define ID_AA64PFR0_SVE_LENGTH			U(4)
+
+#define ID_AA64PFR0_SEL2_SHIFT			U(36)
+#define ID_AA64PFR0_SEL2_MASK			ULL(0xf)
+
+#define ID_AA64PFR0_MPAM_SHIFT			U(40)
+#define ID_AA64PFR0_MPAM_MASK			ULL(0xf)
+
+#define ID_AA64PFR0_DIT_SHIFT			U(48)
+#define ID_AA64PFR0_DIT_MASK			ULL(0xf)
+#define ID_AA64PFR0_DIT_LENGTH			U(4)
+#define ID_AA64PFR0_DIT_SUPPORTED		U(1)
+
+#define ID_AA64PFR0_CSV2_SHIFT			U(56)
+#define ID_AA64PFR0_CSV2_MASK			ULL(0xf)
+#define ID_AA64PFR0_CSV2_LENGTH			U(4)
+#define ID_AA64PFR0_CSV2_2_SUPPORTED		ULL(0x2)
+
 #define ID_AA64PFR0_FEAT_RME_SHIFT		U(52)
 #define ID_AA64PFR0_FEAT_RME_MASK		ULL(0xf)
 #define ID_AA64PFR0_FEAT_RME_LENGTH		U(4)
 #define ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED	U(0)
 #define ID_AA64PFR0_FEAT_RME_V1			U(1)

+#define ID_AA64PFR0_RAS_SHIFT			U(28)
+#define ID_AA64PFR0_RAS_MASK			ULL(0xf)
+#define ID_AA64PFR0_RAS_NOT_SUPPORTED		ULL(0x0)
+#define ID_AA64PFR0_RAS_LENGTH			U(4)
+
 /* Exception level handling */
 #define EL_IMPL_NONE		ULL(0)
 #define EL_IMPL_A64ONLY		ULL(1)
@ -204,8 +219,10 @@
 #define ID_AA64DFR0_TRACEFILT_LENGTH	U(4)

 /* ID_AA64DFR0_EL1.PMS definitions (for ARMv8.2+) */
-#define ID_AA64DFR0_PMS_SHIFT	U(32)
-#define ID_AA64DFR0_PMS_MASK	ULL(0xf)
+#define ID_AA64DFR0_PMS_SHIFT		U(32)
+#define ID_AA64DFR0_PMS_MASK		ULL(0xf)
+#define ID_AA64DFR0_SPE_SUPPORTED	ULL(0x1)
+#define ID_AA64DFR0_SPE_NOT_SUPPORTED   ULL(0x0)

 /* ID_AA64DFR0_EL1.TraceBuffer definitions */
 #define ID_AA64DFR0_TRACEBUFFER_SHIFT		U(44)
@ -222,15 +239,22 @@
 #define ID_AA64ISAR0_RNDR_MASK	ULL(0xf)

 /* ID_AA64ISAR1_EL1 definitions */
-#define ID_AA64ISAR1_EL1	S3_0_C0_C6_1
-#define ID_AA64ISAR1_GPI_SHIFT	U(28)
-#define ID_AA64ISAR1_GPI_MASK	ULL(0xf)
-#define ID_AA64ISAR1_GPA_SHIFT	U(24)
-#define ID_AA64ISAR1_GPA_MASK	ULL(0xf)
-#define ID_AA64ISAR1_API_SHIFT	U(8)
-#define ID_AA64ISAR1_API_MASK	ULL(0xf)
-#define ID_AA64ISAR1_APA_SHIFT	U(4)
-#define ID_AA64ISAR1_APA_MASK	ULL(0xf)
+#define ID_AA64ISAR1_EL1		S3_0_C0_C6_1
+
+#define ID_AA64ISAR1_GPI_SHIFT		U(28)
+#define ID_AA64ISAR1_GPI_MASK		ULL(0xf)
+#define ID_AA64ISAR1_GPA_SHIFT		U(24)
+#define ID_AA64ISAR1_GPA_MASK		ULL(0xf)
+
+#define ID_AA64ISAR1_API_SHIFT		U(8)
+#define ID_AA64ISAR1_API_MASK		ULL(0xf)
+#define ID_AA64ISAR1_APA_SHIFT		U(4)
+#define ID_AA64ISAR1_APA_MASK		ULL(0xf)
+
+#define ID_AA64ISAR1_SB_SHIFT		U(36)
+#define ID_AA64ISAR1_SB_MASK		ULL(0xf)
+#define ID_AA64ISAR1_SB_SUPPORTED	ULL(0x1)
+#define ID_AA64ISAR1_SB_NOT_SUPPORTED	ULL(0x0)

 /* ID_AA64MMFR0_EL1 definitions */
 #define ID_AA64MMFR0_EL1_PARANGE_SHIFT	U(0)
@ -292,17 +316,23 @@
 #define ID_AA64MMFR1_EL1_HCX_NOT_SUPPORTED	ULL(0x0)

 /* ID_AA64MMFR2_EL1 definitions */
-#define ID_AA64MMFR2_EL1		S3_0_C0_C7_2
+#define ID_AA64MMFR2_EL1			S3_0_C0_C7_2

-#define ID_AA64MMFR2_EL1_ST_SHIFT	U(28)
-#define ID_AA64MMFR2_EL1_ST_MASK	ULL(0xf)
+#define ID_AA64MMFR2_EL1_ST_SHIFT		U(28)
+#define ID_AA64MMFR2_EL1_ST_MASK		ULL(0xf)

-#define ID_AA64MMFR2_EL1_CCIDX_SHIFT	U(20)
-#define ID_AA64MMFR2_EL1_CCIDX_MASK	ULL(0xf)
-#define ID_AA64MMFR2_EL1_CCIDX_LENGTH	U(4)
+#define ID_AA64MMFR2_EL1_CCIDX_SHIFT		U(20)
+#define ID_AA64MMFR2_EL1_CCIDX_MASK		ULL(0xf)
+#define ID_AA64MMFR2_EL1_CCIDX_LENGTH		U(4)

-#define ID_AA64MMFR2_EL1_CNP_SHIFT	U(0)
-#define ID_AA64MMFR2_EL1_CNP_MASK	ULL(0xf)
+#define ID_AA64MMFR2_EL1_CNP_SHIFT		U(0)
+#define ID_AA64MMFR2_EL1_CNP_MASK		ULL(0xf)
+
+#define ID_AA64MMFR2_EL1_NV_SHIFT		U(24)
+#define ID_AA64MMFR2_EL1_NV_MASK		ULL(0xf)
+#define ID_AA64MMFR2_EL1_NV_NOT_SUPPORTED	ULL(0x0)
+#define ID_AA64MMFR2_EL1_NV_SUPPORTED		ULL(0x1)
+#define ID_AA64MMFR2_EL1_NV2_SUPPORTED		ULL(0x2)

 /* ID_AA64PFR1_EL1 definitions */
 #define ID_AA64PFR1_EL1_SSBS_SHIFT	U(4)
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@ -140,4 +140,88 @@ static inline unsigned int get_armv9_2_feat_rme_support(void)
 		ID_AA64PFR0_FEAT_RME_SHIFT) & ID_AA64PFR0_FEAT_RME_MASK;
 }

+/*********************************************************************************
+ * Function to identify the presence of FEAT_SB (Speculation Barrier Instruction)
+ ********************************************************************************/
+static inline bool is_armv8_0_feat_sb_present(void)
+{
+	return (((read_id_aa64isar1_el1() >> ID_AA64ISAR1_SB_SHIFT) &
+		ID_AA64ISAR1_SB_MASK) == ID_AA64ISAR1_SB_SUPPORTED);
+}
+
+/*********************************************************************************
+ * Function to identify the presence of FEAT_CSV2_2 (Cache Speculation Variant 2)
+ ********************************************************************************/
+static inline bool is_armv8_0_feat_csv2_2_present(void)
+{
+	return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_CSV2_SHIFT) &
+		ID_AA64PFR0_CSV2_MASK) == ID_AA64PFR0_CSV2_2_SUPPORTED);
+}
+
+/**********************************************************************************
+ * Function to identify the presence of FEAT_SPE (Statistical Profiling Extension)
+ *********************************************************************************/
+static inline bool is_armv8_2_feat_spe_present(void)
+{
+	return (((read_id_aa64dfr0_el1() >> ID_AA64DFR0_PMS_SHIFT) &
+		ID_AA64DFR0_PMS_MASK) != ID_AA64DFR0_SPE_NOT_SUPPORTED);
+}
+
+/*******************************************************************************
+ * Function to identify the presence of FEAT_SVE (Scalable Vector Extension)
+ ******************************************************************************/
+static inline bool is_armv8_2_feat_sve_present(void)
+{
+	return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_SVE_SHIFT) &
+		ID_AA64PFR0_SVE_MASK) == ID_AA64PFR0_SVE_SUPPORTED);
+}
+
+/*******************************************************************************
+ * Function to identify the presence of FEAT_RAS (Reliability,Availability,
+ * and Serviceability Extension)
+ ******************************************************************************/
+static inline bool is_armv8_2_feat_ras_present(void)
+{
+	return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_RAS_SHIFT) &
+		ID_AA64PFR0_RAS_MASK) != ID_AA64PFR0_RAS_NOT_SUPPORTED);
+}
+
+/**************************************************************************
+ * Function to identify the presence of FEAT_DIT (Data Independent Timing)
+ *************************************************************************/
+static inline bool is_armv8_4_feat_dit_present(void)
+{
+	return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_DIT_SHIFT) &
+		ID_AA64PFR0_DIT_MASK) == ID_AA64PFR0_DIT_SUPPORTED);
+}
+
+/*************************************************************************
+ * Function to identify the presence of FEAT_TRF (TraceLift)
+ ************************************************************************/
+static inline bool is_arm8_4_feat_trf_present(void)
+{
+	return (((read_id_aa64dfr0_el1() >> ID_AA64DFR0_TRACEFILT_SHIFT) &
+		ID_AA64DFR0_TRACEFILT_MASK) == ID_AA64DFR0_TRACEFILT_SUPPORTED);
+}
+
+/*******************************************************************************
+ * Function to identify the presence of FEAT_AMUv1 (Activity Monitors-
+ * Extension v1)
+ ******************************************************************************/
+static inline bool is_armv8_4_feat_amuv1_present(void)
+{
+	return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_AMU_SHIFT) &
+		ID_AA64PFR0_AMU_MASK) >= ID_AA64PFR0_AMU_V1);
+}
+
+/********************************************************************************
+ * Function to identify the presence of FEAT_NV2 (Enhanced Nested Virtualization
+ * Support)
+ *******************************************************************************/
+static inline unsigned int get_armv8_4_feat_nv_support(void)
+{
+	return (((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_NV_SHIFT) &
+		ID_AA64MMFR2_EL1_NV_MASK));
+}
+
 #endif /* ARCH_FEATURES_H */
--- a/include/common/feat_detect.h
+++ b/include/common/feat_detect.h
@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef FEAT_DETECT_H
+#define FEAT_DETECT_H
+
+#include <arch_features.h>
+#include <common/debug.h>
+
+/* Function Prototypes */
+void detect_arch_features(void);
+
+/* Macro Definitions */
+#define FEAT_STATE_1	1
+#define FEAT_STATE_2	2
+#define feat_detect_panic(a, b)		((a) ? (void)0 : feature_panic(b))
+
+/*******************************************************************************
+ * Function : feature_panic
+ * Customised panic module with error logging mechanism to list the feature
+ * not supported by the PE.
+ ******************************************************************************/
+static inline void feature_panic(char *feat_name)
+{
+	ERROR("FEAT_%s not supported by the PE\n", feat_name);
+	panic();
+}
+
+#endif /* FEAT_DETECT_H */
--- a/include/lib/el3_runtime/aarch64/context.h
+++ b/include/lib/el3_runtime/aarch64/context.h
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
@ -217,13 +217,13 @@

 // Starting with Armv8.4
 #define CTX_CONTEXTIDR_EL2	U(0x198)
-#define CTX_SDER32_EL2		U(0x1a0)
-#define CTX_TTBR1_EL2		U(0x1a8)
-#define CTX_VDISR_EL2		U(0x1b0)
-#define CTX_VNCR_EL2		U(0x1b8)
-#define CTX_VSESR_EL2		U(0x1c0)
-#define CTX_VSTCR_EL2		U(0x1c8)
-#define CTX_VSTTBR_EL2		U(0x1d0)
+#define CTX_TTBR1_EL2		U(0x1a0)
+#define CTX_VDISR_EL2		U(0x1a8)
+#define CTX_VSESR_EL2		U(0x1b0)
+#define CTX_VSTCR_EL2		U(0x1b8)
+#define CTX_VSTTBR_EL2		U(0x1c0)
+#define CTX_SDER32_EL2		U(0x1c8)
+#define CTX_VNCR_EL2		U(0x1d0)
 #define CTX_TRFCR_EL2		U(0x1d8)

 // Starting with Armv8.5
--- a/lib/el3_runtime/aarch64/context.S
+++ b/lib/el3_runtime/aarch64/context.S
@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
@ -13,14 +13,14 @@
 #if CTX_INCLUDE_EL2_REGS
 	.global	el2_sysregs_context_save
 	.global	el2_sysregs_context_restore
-#endif
+#endif /* CTX_INCLUDE_EL2_REGS */

 	.global	el1_sysregs_context_save
 	.global	el1_sysregs_context_restore
 #if CTX_INCLUDE_FPREGS
 	.global	fpregs_context_save
 	.global	fpregs_context_restore
-#endif
+#endif /* CTX_INCLUDE_FPREGS */
 	.global	prepare_el3_entry
 	.global	restore_gp_pmcr_pauth_regs
 	.global save_and_update_ptw_el1_sys_regs
@ -62,7 +62,7 @@ func el2_sysregs_context_save
 #if CTX_INCLUDE_AARCH32_REGS
 	mrs	x16, dbgvcr32_el2
 	str	x16, [x0, #CTX_DBGVCR32_EL2]
-#endif
+#endif /* CTX_INCLUDE_AARCH32_REGS */

 	mrs	x9, elr_el2
 	mrs	x10, esr_el2
@ -91,7 +91,8 @@ func el2_sysregs_context_save
 #if ENABLE_SPE_FOR_LOWER_ELS
 	mrs	x13, PMSCR_EL2
 	str	x13, [x0, #CTX_PMSCR_EL2]
-#endif
+#endif /* ENABLE_SPE_FOR_LOWER_ELS */
+
 	mrs	x14, sctlr_el2
 	str	x14, [x0, #CTX_SCTLR_EL2]

@ -118,7 +119,7 @@ func el2_sysregs_context_save
 #if CTX_INCLUDE_MTE_REGS
 	mrs	x9, TFSR_EL2
 	str	x9, [x0, #CTX_TFSR_EL2]
-#endif
+#endif /* CTX_INCLUDE_MTE_REGS */

 #if ENABLE_MPAM_FOR_LOWER_ELS
 	mrs	x10, MPAM2_EL2
@ -143,7 +144,7 @@ func el2_sysregs_context_save
 	mrs	x11, MPAMVPM7_EL2
 	mrs	x12, MPAMVPMV_EL2
 	stp	x11, x12, [x0, #CTX_MPAMVPM7_EL2]
-#endif
+#endif /* ENABLE_MPAM_FOR_LOWER_ELS */

 #if ENABLE_FEAT_FGT
 	mrs	x13, HDFGRTR_EL2
@ -152,7 +153,7 @@ func el2_sysregs_context_save
   	stp	x13, x14, [x0, #CTX_HDFGRTR_EL2]
 #else
   	str	x13, [x0, #CTX_HDFGRTR_EL2]
-#endif
+#endif /* ENABLE_FEAT_AMUv1 */
 	mrs	x15, HDFGWTR_EL2
 	mrs	x16, HFGITR_EL2
 	stp	x15, x16, [x0, #CTX_HDFGWTR_EL2]
@ -160,48 +161,80 @@ func el2_sysregs_context_save
 	mrs	x9, HFGRTR_EL2
 	mrs	x10, HFGWTR_EL2
 	stp	x9, x10, [x0, #CTX_HFGRTR_EL2]
-#endif
+#endif /* ENABLE_FEAT_FGT */

 #if ENABLE_FEAT_ECV
 	mrs	x11, CNTPOFF_EL2
 	str	x11, [x0, #CTX_CNTPOFF_EL2]
-#endif
+#endif /* ENABLE_FEAT_ECV */

-#if ARM_ARCH_AT_LEAST(8, 4)
-	mrs	x12, contextidr_el2
-	str	x12, [x0, #CTX_CONTEXTIDR_EL2]
+#if ENABLE_FEAT_VHE
+	/*
+	 * CONTEXTIDR_EL2 register is saved only when FEAT_VHE or
+	 * FEAT_Debugv8p2 (currently not in TF-A) is supported.
+	 */
+	mrs	x9, contextidr_el2
+	mrs	x10, ttbr1_el2
+	stp	x9, x10, [x0, #CTX_CONTEXTIDR_EL2]
+#endif /* ENABLE_FEAT_VHE */

-#if CTX_INCLUDE_AARCH32_REGS
-	mrs	x13, sder32_el2
-	str	x13, [x0, #CTX_SDER32_EL2]
-#endif
-	mrs	x14, ttbr1_el2
-	mrs	x15, vdisr_el2
-	stp	x14, x15, [x0, #CTX_TTBR1_EL2]
+#if RAS_EXTENSION
+	/*
+	 * VDISR_EL2 and VSESR_EL2 registers are saved only when
+	 * FEAT_RAS is supported.
+	 */
+	mrs	x11, vdisr_el2
+	mrs	x12, vsesr_el2
+	stp	x11, x12, [x0, #CTX_VDISR_EL2]
+#endif /* RAS_EXTENSION */
+
+#if ENABLE_FEAT_SEL2
+	/*
+	 * VSTCR_EL2 and VSTTBR_EL2 registers are saved only
+	 * when FEAT_SEL2 is supported.
+	 */
+	mrs	x13, vstcr_el2
+	mrs	x14, vsttbr_el2
+	stp	x13, x14, [x0, #CTX_VSTCR_EL2]
+#endif /* ENABLE_FEAT_SEL2 */
+
+#if CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2
+	/*
+	 * SDER32_EL2 register is saved only when EL2 and EL1
+	 * capable of using Aarch32 and FEAT_SEL2 is supported.
+	 */
+	mrs	x15, sder32_el2
+	str	x15, [x0, #CTX_SDER32_EL2]
+#endif /* CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2 */

 #if CTX_INCLUDE_NEVE_REGS
+	/*
+	 * VNCR_EL2 register is saved only when FEAT_NV2 is supported.
+	 */
 	mrs	x16, vncr_el2
 	str	x16, [x0, #CTX_VNCR_EL2]
-#endif
+#endif /* CTX_INCLUDE_NEVE_REGS */

-	mrs	x9, vsesr_el2
-	mrs	x10, vstcr_el2
-	stp	x9, x10, [x0, #CTX_VSESR_EL2]
-
-	mrs	x11, vsttbr_el2
+#if ENABLE_TRF_FOR_NS
+	/*
+	 * TRFCR_EL2 register is saved only when FEAT_TRF is supported.
+	 */
 	mrs	x12, TRFCR_EL2
-	stp	x11, x12, [x0, #CTX_VSTTBR_EL2]
-#endif
+	str	x12, [x0, #CTX_TRFCR_EL2]
+#endif /* ENABLE_TRF_FOR_NS */

-#if ARM_ARCH_AT_LEAST(8, 5)
+#if ENABLE_FEAT_CSV2_2
+	/*
+	 * SCXTNUM_EL2 register is saved only when FEAT_CSV2_2 is supported.
+	 */
 	mrs	x13, scxtnum_el2
 	str	x13, [x0, #CTX_SCXTNUM_EL2]
-#endif
+#endif /* ENABLE_FEAT_CSV2_2 */

 #if ENABLE_FEAT_HCX
 	mrs	x14, hcrx_el2
 	str	x14, [x0, #CTX_HCRX_EL2]
-#endif
+#endif /* ENABLE_FEAT_HCX */

 	ret
 endfunc el2_sysregs_context_save
@ -241,7 +274,7 @@ func el2_sysregs_context_restore
 #if CTX_INCLUDE_AARCH32_REGS
 	ldr	x16, [x0, #CTX_DBGVCR32_EL2]
 	msr	dbgvcr32_el2, x16
-#endif
+#endif /* CTX_INCLUDE_AARCH32_REGS */

 	ldp	x9, x10, [x0, #CTX_ELR_EL2]
 	msr	elr_el2, x9
@ -270,7 +303,8 @@ func el2_sysregs_context_restore
 #if ENABLE_SPE_FOR_LOWER_ELS
 	ldr	x13, [x0, #CTX_PMSCR_EL2]
 	msr	PMSCR_EL2, x13
-#endif
+#endif /* ENABLE_SPE_FOR_LOWER_ELS */
+
 	ldr	x14, [x0, #CTX_SCTLR_EL2]
 	msr	sctlr_el2, x14

@ -297,7 +331,7 @@ func el2_sysregs_context_restore
 #if CTX_INCLUDE_MTE_REGS
 	ldr	x9, [x0, #CTX_TFSR_EL2]
 	msr	TFSR_EL2, x9
-#endif
+#endif /* CTX_INCLUDE_MTE_REGS */

 #if ENABLE_MPAM_FOR_LOWER_ELS
 	ldr	x10, [x0, #CTX_MPAM2_EL2]
@ -322,7 +356,7 @@ func el2_sysregs_context_restore
 	ldp	x11, x12, [x0, #CTX_MPAMVPM7_EL2]
 	msr	MPAMVPM7_EL2, x11
 	msr	MPAMVPMV_EL2, x12
-#endif
+#endif /* ENABLE_MPAM_FOR_LOWER_ELS */

 #if ENABLE_FEAT_FGT
 #if ENABLE_FEAT_AMUv1
@ -330,7 +364,7 @@ func el2_sysregs_context_restore
 	msr	HAFGRTR_EL2, x14
 #else
 	ldr	x13, [x0, #CTX_HDFGRTR_EL2]
-#endif
+#endif /* ENABLE_FEAT_AMUv1 */
 	msr	HDFGRTR_EL2, x13

 	ldp	x15, x16, [x0, #CTX_HDFGWTR_EL2]
@ -340,48 +374,80 @@ func el2_sysregs_context_restore
 	ldp	x9, x10, [x0, #CTX_HFGRTR_EL2]
 	msr	HFGRTR_EL2, x9
 	msr	HFGWTR_EL2, x10
-#endif
+#endif /* ENABLE_FEAT_FGT */

 #if ENABLE_FEAT_ECV
 	ldr	x11, [x0, #CTX_CNTPOFF_EL2]
 	msr	CNTPOFF_EL2, x11
-#endif
+#endif /* ENABLE_FEAT_ECV */

-#if ARM_ARCH_AT_LEAST(8, 4)
-	ldr	x12, [x0, #CTX_CONTEXTIDR_EL2]
-	msr	contextidr_el2, x12
+#if ENABLE_FEAT_VHE
+	/*
+	 * CONTEXTIDR_EL2 register is restored only when FEAT_VHE or
+	 * FEAT_Debugv8p2 (currently not in TF-A) is supported.
+	 */
+	ldp	x9, x10, [x0, #CTX_CONTEXTIDR_EL2]
+	msr	contextidr_el2, x9
+	msr	ttbr1_el2, x10
+#endif /* ENABLE_FEAT_VHE */

-#if CTX_INCLUDE_AARCH32_REGS
-	ldr	x13, [x0, #CTX_SDER32_EL2]
-	msr	sder32_el2, x13
-#endif
-	ldp	x14, x15, [x0, #CTX_TTBR1_EL2]
-	msr	ttbr1_el2, x14
-	msr	vdisr_el2, x15
+#if RAS_EXTENSION
+	/*
+	 * VDISR_EL2 and VSESR_EL2 registers are restored only when FEAT_RAS
+	 * is supported.
+	 */
+	ldp	x11, x12, [x0, #CTX_VDISR_EL2]
+	msr	vdisr_el2, x11
+	msr	vsesr_el2, x12
+#endif /* RAS_EXTENSION */
+
+#if ENABLE_FEAT_SEL2
+	/*
+	 * VSTCR_EL2 and VSTTBR_EL2 registers are restored only when FEAT_SEL2
+	 * is supported.
+	 */
+	ldp	x13, x14, [x0, #CTX_VSTCR_EL2]
+	msr	vstcr_el2, x13
+	msr	vsttbr_el2, x14
+#endif /* ENABLE_FEAT_SEL2 */
+
+#if CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2
+	/*
+	 * SDER32_EL2 register is restored only when EL2 and EL1 capable of using
+	 * Aarch32 and FEAT_SEL2 is supported.
+	 */
+	ldr	x15, [x0, #CTX_SDER32_EL2]
+	msr	sder32_el2, x15
+#endif /* CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2 */

 #if CTX_INCLUDE_NEVE_REGS
+	/*
+	 * VNCR_EL2 register is restored only when FEAT_NV2 is supported.
+	 */
 	ldr	x16, [x0, #CTX_VNCR_EL2]
 	msr	vncr_el2, x16
-#endif
+#endif /* CTX_INCLUDE_NEVE_REGS */

-	ldp	x9, x10, [x0, #CTX_VSESR_EL2]
-	msr	vsesr_el2, x9
-	msr	vstcr_el2, x10
-
-	ldp	x11, x12, [x0, #CTX_VSTTBR_EL2]
-	msr	vsttbr_el2, x11
+#if ENABLE_TRF_FOR_NS
+	/*
+	 * TRFCR_EL2 register is restored only when FEAT_TRF is supported.
+	 */
+	ldr	x12, [x0, #CTX_TRFCR_EL2]
 	msr	TRFCR_EL2, x12
-#endif
+#endif /* ENABLE_TRF_FOR_NS */

-#if ARM_ARCH_AT_LEAST(8, 5)
+#if ENABLE_FEAT_CSV2_2
+	/*
+	 * SCXTNUM_EL2 register is restored only when FEAT_CSV2_2 is supported.
+	 */
 	ldr	x13, [x0, #CTX_SCXTNUM_EL2]
 	msr	scxtnum_el2, x13
-#endif
+#endif /* ENABLE_FEAT_CSV2_2 */

 #if ENABLE_FEAT_HCX
 	ldr	x14, [x0, #CTX_HCRX_EL2]
 	msr	hcrx_el2, x14
-#endif
+#endif /* ENABLE_FEAT_HCX */

 	ret
 endfunc el2_sysregs_context_restore
@ -405,7 +471,7 @@ func el1_sysregs_context_save
 	mrs	x15, sctlr_el1
 	mrs	x16, tcr_el1
 	stp	x15, x16, [x0, #CTX_SCTLR_EL1]
-#endif
+#endif /* ERRATA_SPECULATIVE_AT */

 	mrs	x17, cpacr_el1
 	mrs	x9, csselr_el1
@ -456,7 +522,7 @@ func el1_sysregs_context_save
 	mrs	x15, dacr32_el2
 	mrs	x16, ifsr32_el2
 	stp	x15, x16, [x0, #CTX_DACR32_EL2]
-#endif
+#endif /* CTX_INCLUDE_AARCH32_REGS */

 	/* Save NS timer registers if the build has instructed so */
 #if NS_TIMER_SWITCH
@ -470,7 +536,7 @@ func el1_sysregs_context_save

 	mrs	x14, cntkctl_el1
 	str	x14, [x0, #CTX_CNTKCTL_EL1]
-#endif
+#endif /* NS_TIMER_SWITCH */

 	/* Save MTE system registers if the build has instructed so */
 #if CTX_INCLUDE_MTE_REGS
@ -481,7 +547,7 @@ func el1_sysregs_context_save
 	mrs	x9, RGSR_EL1
 	mrs	x10, GCR_EL1
 	stp	x9, x10, [x0, #CTX_RGSR_EL1]
-#endif
+#endif /* CTX_INCLUDE_MTE_REGS */

 	ret
 endfunc el1_sysregs_context_save
@ -504,7 +570,7 @@ func el1_sysregs_context_restore
 	ldp	x15, x16, [x0, #CTX_SCTLR_EL1]
 	msr	sctlr_el1, x15
 	msr	tcr_el1, x16
-#endif
+#endif /* ERRATA_SPECULATIVE_AT */

 	ldp	x17, x9, [x0, #CTX_CPACR_EL1]
 	msr	cpacr_el1, x17
@ -555,7 +621,8 @@ func el1_sysregs_context_restore
 	ldp	x15, x16, [x0, #CTX_DACR32_EL2]
 	msr	dacr32_el2, x15
 	msr	ifsr32_el2, x16
-#endif
+#endif /* CTX_INCLUDE_AARCH32_REGS */
+
 	/* Restore NS timer registers if the build has instructed so */
 #if NS_TIMER_SWITCH
 	ldp	x10, x11, [x0, #CTX_CNTP_CTL_EL0]
@ -568,7 +635,8 @@ func el1_sysregs_context_restore

 	ldr	x14, [x0, #CTX_CNTKCTL_EL1]
 	msr	cntkctl_el1, x14
-#endif
+#endif /* NS_TIMER_SWITCH */
+
 	/* Restore MTE system registers if the build has instructed so */
 #if CTX_INCLUDE_MTE_REGS
 	ldp	x11, x12, [x0, #CTX_TFSRE0_EL1]
@ -578,7 +646,7 @@ func el1_sysregs_context_restore
 	ldp	x13, x14, [x0, #CTX_RGSR_EL1]
 	msr	RGSR_EL1, x13
 	msr	GCR_EL1, x14
-#endif
+#endif /* CTX_INCLUDE_MTE_REGS */

 	/* No explict ISB required here as ERET covers it */
 	ret
@ -626,7 +694,7 @@ func fpregs_context_save
 #if CTX_INCLUDE_AARCH32_REGS
 	mrs	x11, fpexc32_el2
 	str	x11, [x0, #CTX_FP_FPEXC32_EL2]
-#endif
+#endif /* CTX_INCLUDE_AARCH32_REGS */
 	ret
 endfunc fpregs_context_save

@ -671,7 +739,8 @@ func fpregs_context_restore
 #if CTX_INCLUDE_AARCH32_REGS
 	ldr	x11, [x0, #CTX_FP_FPEXC32_EL2]
 	msr	fpexc32_el2, x11
-#endif
+#endif /* CTX_INCLUDE_AARCH32_REGS */
+
 	/*
 	 * No explict ISB required here as ERET to
 	 * switch to secure EL1 or non-secure world
@ -688,13 +757,13 @@ endfunc fpregs_context_restore
 	 * in ARM DDI 0487F.c page J1-7635 to a default value.
 	 */
 	.macro set_unset_pstate_bits
-        /*
-         * If Data Independent Timing (DIT) functionality is implemented,
-         * always enable DIT in EL3
-         */
+	/*
+	 * If Data Independent Timing (DIT) functionality is implemented,
+	 * always enable DIT in EL3
+	 */
 #if ENABLE_FEAT_DIT
-        mov     x8, #DIT_BIT
-        msr     DIT, x8
+	mov     x8, #DIT_BIT
+	msr     DIT, x8
 #endif /* ENABLE_FEAT_DIT */
 	.endm /* set_unset_pstate_bits */

@ -933,7 +1002,7 @@ func el3_exit
 	mrs	x17, spsel
 	cmp	x17, #MODE_SP_EL0
 	ASM_ASSERT(eq)
-#endif
+#endif /* ENABLE_ASSERTIONS */

 	/* ----------------------------------------------------------
 	 * Save the current SP_EL0 i.e. the EL3 runtime stack which
@ -971,7 +1040,7 @@ func el3_exit
 	isb
 	msr	S3_6_C1_C2_0, x20 /* zcr_el3 */
 sve_not_enabled:
-#endif
+#endif /* IMAGE_BL31 */

 #if IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639
 	/* ----------------------------------------------------------
@ -982,7 +1051,8 @@ sve_not_enabled:
 	cbz	x17, 1f
 	blr	x17
 1:
-#endif
+#endif /* IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639 */
+
 	restore_ptw_el1_sys_regs

 	/* ----------------------------------------------------------
@ -1005,10 +1075,12 @@ sve_not_enabled:
 	esb
 #else
 	dsb	sy
-#endif
+#endif /* IMAGE_BL31 && RAS_EXTENSION */
+
 #ifdef IMAGE_BL31
 	str	xzr, [sp, #CTX_EL3STATE_OFFSET + CTX_IS_IN_EL3]
-#endif
+#endif /* IMAGE_BL31 */
+
 	exception_return

 endfunc el3_exit
--- a/make_helpers/arch_features.mk
+++ b/make_helpers/arch_features.mk
@ -0,0 +1,36 @@
+#
+# Copyright (c) 2022, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+# This file lists all the checks related to the Architectural Feature
+# Enablement flags, based on the Architectural version.
+
+# Enable the features which are mandatory from ARCH version 8.1 and upwards.
+ifeq "8.1" "$(word 1, $(sort 8.1 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_PAN		=	1
+ENABLE_FEAT_VHE		=	1
+endif
+
+# Enable the features which are mandatory from ARCH version 8.4 and upwards.
+ifeq "8.4" "$(word 1, $(sort 8.4 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_DIT		=	1
+ENABLE_FEAT_SEL2	=	1
+endif
+
+# Enable the features which are mandatory from ARCH version 8.5 and upwards.
+ifeq "8.5" "$(word 1, $(sort 8.5 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_SB		=	1
+endif
+
+# Enable the features which are mandatory from ARCH version 8.6 and upwards.
+ifeq "8.6" "$(word 1, $(sort 8.6 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_FGT		=	1
+ENABLE_FEAT_ECV		=	1
+endif
+
+# Enable the features which are mandatory from ARCH version 8.7 and upwards.
+ifeq "8.7" "$(word 1, $(sort 8.7 $(ARM_ARCH_MAJOR).$(ARM_ARCH_MINOR)))"
+ENABLE_FEAT_HCX		=	1
+endif
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@ -133,12 +133,18 @@ ENABLE_BTI			:= 0
 # Use BRANCH_PROTECTION to enable PAUTH.
 ENABLE_PAUTH			:= 0

-# Flag to enable access to the HCRX_EL2 register by setting SCR_EL3.HXEn.
-ENABLE_FEAT_HCX			:= 0
-
 # Flag to enable access to the HAFGRTR_EL2 register
 ENABLE_FEAT_AMUv1		:= 0

+# Flag to enable AMUv1p1 extension.
+ENABLE_FEAT_AMUv1p1		:= 0
+
+# Flag to enable CSV2_2 extension.
+ENABLE_FEAT_CSV2_2 		:= 0
+
+# Flag to enable access to the HCRX_EL2 register by setting SCR_EL3.HXEn.
+ENABLE_FEAT_HCX			:= 0
+
 # Flag to enable access to the HDFGRTR_EL2 register
 ENABLE_FEAT_FGT			:= 0

@ -148,6 +154,21 @@ ENABLE_FEAT_ECV			:= 0
 # Flag to enable use of the DIT feature.
 ENABLE_FEAT_DIT			:= 0

+# Flag to enable access to Privileged Access Never bit of PSTATE.
+ENABLE_FEAT_PAN			:= 0
+
+# Flag to enable access to the Random Number Generator registers
+ENABLE_FEAT_RNG			:= 0
+
+# Flag to enable Speculation Barrier Instruction
+ENABLE_FEAT_SB			:= 0
+
+# Flag to enable Secure EL-2 feature.
+ENABLE_FEAT_SEL2		:= 0
+
+# Flag to enable Virtualization Host Extensions
+ENABLE_FEAT_VHE 		:= 0
+
 # By default BL31 encryption disabled
 ENCRYPT_BL31			:= 0

@ -166,6 +187,9 @@ ERROR_DEPRECATED		:= 0
 # Fault injection support
 FAULT_INJECTION_SUPPORT		:= 0

+# Flag to enable architectural features detection mechanism
+FEATURE_DETECTION		:= 0
+
 # Byte alignment that each component in FIP is aligned to
 FIP_ALIGN			:= 0