diff --git a/include/lib/aarch64/arch.h b/include/lib/aarch64/arch.h
index 07661c9..39b2a42 100644
--- a/include/lib/aarch64/arch.h
+++ b/include/lib/aarch64/arch.h
@@ -204,6 +204,10 @@
 
 /* ID_AA64MMFR2_EL1 definitions */
 #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_CNP_SHIFT	U(0)
 #define ID_AA64MMFR2_EL1_CNP_MASK	ULL(0xf)
 
@@ -427,6 +431,7 @@
 
 #define TCR_TxSZ_MIN		ULL(16)
 #define TCR_TxSZ_MAX		ULL(39)
+#define TCR_TxSZ_MAX_TTST	ULL(48)
 
 /* (internal) physical address size bits in EL3/EL1 */
 #define TCR_PS_BITS_4GB		ULL(0x0)
diff --git a/include/lib/aarch64/arch_features.h b/include/lib/aarch64/arch_features.h
index 2b09ba0..da8b6e4 100644
--- a/include/lib/aarch64/arch_features.h
+++ b/include/lib/aarch64/arch_features.h
@@ -11,10 +11,22 @@
 
 #include <arch_helpers.h>
 
+static inline bool is_armv7_gentimer_present(void)
+{
+	/* The Generic Timer is always present in an ARMv8-A implementation */
+	return true;
+}
+
 static inline bool is_armv8_2_ttcnp_present(void)
 {
 	return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_CNP_SHIFT) &
 		ID_AA64MMFR2_EL1_CNP_MASK) != 0U;
 }
 
+static inline bool is_armv8_4_ttst_present(void)
+{
+	return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_ST_SHIFT) &
+		ID_AA64MMFR2_EL1_ST_MASK) == 1U;
+}
+
 #endif /* ARCH_FEATURES_H */
diff --git a/include/lib/aarch64/arch_helpers.h b/include/lib/aarch64/arch_helpers.h
index d98ce48..750bbbd 100644
--- a/include/lib/aarch64/arch_helpers.h
+++ b/include/lib/aarch64/arch_helpers.h
@@ -182,6 +182,7 @@
 DEFINE_SYSREG_READ_FUNC(id_aa64isar1_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64pfr0_el1)
 DEFINE_SYSREG_READ_FUNC(id_aa64dfr0_el1)
+DEFINE_SYSREG_READ_FUNC(id_afr0_el1)
 DEFINE_SYSREG_READ_FUNC(CurrentEl)
 DEFINE_SYSREG_READ_FUNC(ctr_el0)
 DEFINE_SYSREG_RW_FUNCS(daif)