diff --git a/lib/extensions/amu/aarch32/amu.c b/lib/extensions/amu/aarch32/amu.c
index d450bd6..be37006 100644
--- a/lib/extensions/amu/aarch32/amu.c
+++ b/lib/extensions/amu/aarch32/amu.c
@@ -7,26 +7,30 @@
 #include <amu.h>
 #include <arch.h>
 #include <arch_helpers.h>
+#include <debug.h>
 
 void amu_enable(int el2_unused)
 {
 	uint64_t features;
 
 	features = read_id_pfr0() >> ID_PFR0_AMU_SHIFT;
-	if ((features & ID_PFR0_AMU_MASK) == 1) {
-		if (el2_unused) {
-			uint64_t v;
-
-			/*
-			 * Non-secure access from EL0 or EL1 to the Activity Monitor
-			 * registers do not trap to EL2.
-			 */
-			v = read_hcptr();
-			v &= ~TAM_BIT;
-			write_hcptr(v);
-		}
-
-		/* Enable group 0 counters */
-		write_amcntenset0(AMU_GROUP0_COUNTERS_MASK);
+	if ((features & ID_PFR0_AMU_MASK) != 1) {
+		WARN("Cannot enable AMU - not supported\n");
+		return;
 	}
+
+	if (el2_unused) {
+		uint64_t v;
+
+		/*
+		 * Non-secure access from EL0 or EL1 to the Activity Monitor
+		 * registers do not trap to EL2.
+		 */
+		v = read_hcptr();
+		v &= ~TAM_BIT;
+		write_hcptr(v);
+	}
+
+	/* Enable group 0 counters */
+	write_amcntenset0(AMU_GROUP0_COUNTERS_MASK);
 }
diff --git a/lib/extensions/amu/aarch64/amu.c b/lib/extensions/amu/aarch64/amu.c
index c00aa5a..27936a2 100644
--- a/lib/extensions/amu/aarch64/amu.c
+++ b/lib/extensions/amu/aarch64/amu.c
@@ -5,38 +5,106 @@
  */
 
 #include <amu.h>
+#include <amu_private.h>
 #include <arch.h>
 #include <arch_helpers.h>
+#include <assert.h>
+#include <debug.h>
 
-void amu_enable(int el2_unused)
+#define AMU_GROUP0_NR_COUNTERS	4
+
+int amu_supported(void)
 {
 	uint64_t features;
 
 	features = read_id_aa64pfr0_el1() >> ID_AA64PFR0_AMU_SHIFT;
-	if ((features & ID_AA64PFR0_AMU_MASK) == 1) {
-		uint64_t v;
+	return (features & ID_AA64PFR0_AMU_MASK) == 1;
+}
 
-		if (el2_unused) {
-			/*
-			 * CPTR_EL2.TAM: Set to zero so any accesses to
-			 * the Activity Monitor registers do not trap to EL2.
-			 */
-			v = read_cptr_el2();
-			v &= ~CPTR_EL2_TAM_BIT;
-			write_cptr_el2(v);
-		}
+/*
+ * Enable counters.  This function is meant to be invoked
+ * by the context management library before exiting from EL3.
+ */
+void amu_enable(int el2_unused)
+{
+	uint64_t v;
 
-		/*
-		 * CPTR_EL3.TAM: Set to zero so that any accesses to
-		 * the Activity Monitor registers do not trap to EL3.
-		 */
-		v = read_cptr_el3();
-		v &= ~TAM_BIT;
-		write_cptr_el3(v);
-
-		/* Enable group 0 counters */
-		write_amcntenset0_el0(AMU_GROUP0_COUNTERS_MASK);
-		/* Enable group 1 counters */
-		write_amcntenset1_el0(AMU_GROUP1_COUNTERS_MASK);
+	if (!amu_supported()) {
+		WARN("Cannot enable AMU - not supported\n");
+		return;
 	}
+
+	if (el2_unused) {
+		/*
+		 * CPTR_EL2.TAM: Set to zero so any accesses to
+		 * the Activity Monitor registers do not trap to EL2.
+		 */
+		v = read_cptr_el2();
+		v &= ~CPTR_EL2_TAM_BIT;
+		write_cptr_el2(v);
+	}
+
+	/*
+	 * CPTR_EL3.TAM: Set to zero so that any accesses to
+	 * the Activity Monitor registers do not trap to EL3.
+	 */
+	v = read_cptr_el3();
+	v &= ~TAM_BIT;
+	write_cptr_el3(v);
+
+	/* Enable group 0 counters */
+	write_amcntenset0_el0(AMU_GROUP0_COUNTERS_MASK);
+	/* Enable group 1 counters */
+	write_amcntenset1_el0(AMU_GROUP1_COUNTERS_MASK);
+}
+
+/* Read the group 0 counter identified by the given `idx`. */
+uint64_t amu_group0_cnt_read(int idx)
+{
+	assert(amu_supported());
+	assert(idx >= 0 && idx < AMU_GROUP0_NR_COUNTERS);
+
+	return amu_group0_cnt_read_internal(idx);
+}
+
+/* Write the group 0 counter identified by the given `idx` with `val`. */
+void amu_group0_cnt_write(int idx, uint64_t val)
+{
+	assert(amu_supported());
+	assert(idx >= 0 && idx < AMU_GROUP0_NR_COUNTERS);
+
+	amu_group0_cnt_write_internal(idx, val);
+	isb();
+}
+
+/* Read the group 1 counter identified by the given `idx`. */
+uint64_t amu_group1_cnt_read(int idx)
+{
+	assert(amu_supported());
+	assert(idx >= 0 && idx < AMU_GROUP1_NR_COUNTERS);
+
+	return amu_group1_cnt_read_internal(idx);
+}
+
+/* Write the group 1 counter identified by the given `idx` with `val`. */
+void amu_group1_cnt_write(int idx, uint64_t val)
+{
+	assert(amu_supported());
+	assert(idx >= 0 && idx < AMU_GROUP1_NR_COUNTERS);
+
+	amu_group1_cnt_write_internal(idx, val);
+	isb();
+}
+
+/*
+ * Program the event type register for the given `idx` with
+ * the event number `val`.
+ */
+void amu_group1_set_evtype(int idx, unsigned int val)
+{
+	assert(amu_supported());
+	assert (idx >= 0 && idx < AMU_GROUP1_NR_COUNTERS);
+
+	amu_group1_set_evtype_internal(idx, val);
+	isb();
 }
diff --git a/lib/extensions/amu/aarch64/amu_helpers.S b/lib/extensions/amu/aarch64/amu_helpers.S
new file mode 100644
index 0000000..e0b1f56
--- /dev/null
+++ b/lib/extensions/amu/aarch64/amu_helpers.S
@@ -0,0 +1,281 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <assert_macros.S>
+#include <asm_macros.S>
+
+	.globl	amu_group0_cnt_read_internal
+	.globl	amu_group0_cnt_write_internal
+	.globl	amu_group1_cnt_read_internal
+	.globl	amu_group1_cnt_write_internal
+	.globl	amu_group1_set_evtype_internal
+
+/*
+ * uint64_t amu_group0_cnt_read_internal(int idx);
+ *
+ * Given `idx`, read the corresponding AMU counter
+ * and return it in `x0`.
+ */
+func amu_group0_cnt_read_internal
+#if ENABLE_ASSERTIONS
+	/*
+	 * It can be dangerous to call this function with an
+	 * out of bounds index.  Ensure `idx` is valid.
+	 */
+	mov	x1, x0
+	lsr	x1, x1, #2
+	cmp	x1, #0
+	ASM_ASSERT(eq)
+#endif
+
+	/*
+	 * Given `idx` calculate address of mrs/ret instruction pair
+	 * in the table below.
+	 */
+	adr	x1, 1f
+	lsl	x0, x0, #3		/* each mrs/ret sequence is 8 bytes */
+	add	x1, x1, x0
+	br	x1
+
+1:
+	mrs	x0, AMEVCNTR00_EL0	/* index 0 */
+	ret
+	mrs	x0, AMEVCNTR01_EL0	/* index 1 */
+	ret
+	mrs	x0, AMEVCNTR02_EL0	/* index 2 */
+	ret
+	mrs	x0, AMEVCNTR03_EL0	/* index 3 */
+	ret
+endfunc amu_group0_cnt_read_internal
+
+/*
+ * void amu_group0_cnt_write_internal(int idx, uint64_t val);
+ *
+ * Given `idx`, write `val` to the corresponding AMU counter.
+ */
+func amu_group0_cnt_write_internal
+#if ENABLE_ASSERTIONS
+	/*
+	 * It can be dangerous to call this function with an
+	 * out of bounds index.  Ensure `idx` is valid.
+	 */
+	mov	x2, x0
+	lsr	x2, x2, #2
+	cmp	x2, #0
+	ASM_ASSERT(eq)
+#endif
+
+	/*
+	 * Given `idx` calculate address of mrs/ret instruction pair
+	 * in the table below.
+	 */
+	adr	x2, 1f
+	lsl	x0, x0, #3		/* each msr/ret sequence is 8 bytes */
+	add	x2, x2, x0
+	br	x2
+
+1:
+	msr	AMEVCNTR00_EL0, x1	/* index 0 */
+	ret
+	msr	AMEVCNTR01_EL0, x1	/* index 1 */
+	ret
+	msr	AMEVCNTR02_EL0, x1	/* index 2 */
+	ret
+	msr	AMEVCNTR03_EL0, x1	/* index 3 */
+	ret
+endfunc amu_group0_cnt_write_internal
+
+/*
+ * uint64_t amu_group1_cnt_read_internal(int idx);
+ *
+ * Given `idx`, read the corresponding AMU counter
+ * and return it in `x0`.
+ */
+func amu_group1_cnt_read_internal
+#if ENABLE_ASSERTIONS
+	/*
+	 * It can be dangerous to call this function with an
+	 * out of bounds index.  Ensure `idx` is valid.
+	 */
+	mov	x1, x0
+	lsr	x1, x1, #4
+	cmp	x1, #0
+	ASM_ASSERT(eq)
+#endif
+
+	/*
+	 * Given `idx` calculate address of mrs/ret instruction pair
+	 * in the table below.
+	 */
+	adr	x1, 1f
+	lsl	x0, x0, #3		/* each mrs/ret sequence is 8 bytes */
+	add	x1, x1, x0
+	br	x1
+
+1:
+	mrs	x0, AMEVCNTR10_EL0	/* index 0 */
+	ret
+	mrs	x0, AMEVCNTR11_EL0	/* index 1 */
+	ret
+	mrs	x0, AMEVCNTR12_EL0	/* index 2 */
+	ret
+	mrs	x0, AMEVCNTR13_EL0	/* index 3 */
+	ret
+	mrs	x0, AMEVCNTR14_EL0	/* index 4 */
+	ret
+	mrs	x0, AMEVCNTR15_EL0	/* index 5 */
+	ret
+	mrs	x0, AMEVCNTR16_EL0	/* index 6 */
+	ret
+	mrs	x0, AMEVCNTR17_EL0	/* index 7 */
+	ret
+	mrs	x0, AMEVCNTR18_EL0	/* index 8 */
+	ret
+	mrs	x0, AMEVCNTR19_EL0	/* index 9 */
+	ret
+	mrs	x0, AMEVCNTR1A_EL0	/* index 10 */
+	ret
+	mrs	x0, AMEVCNTR1B_EL0	/* index 11 */
+	ret
+	mrs	x0, AMEVCNTR1C_EL0	/* index 12 */
+	ret
+	mrs	x0, AMEVCNTR1D_EL0	/* index 13 */
+	ret
+	mrs	x0, AMEVCNTR1E_EL0	/* index 14 */
+	ret
+	mrs	x0, AMEVCNTR1F_EL0	/* index 15 */
+	ret
+endfunc amu_group1_cnt_read_internal
+
+/*
+ * void amu_group1_cnt_write_internal(int idx, uint64_t val);
+ *
+ * Given `idx`, write `val` to the corresponding AMU counter.
+ */
+func amu_group1_cnt_write_internal
+#if ENABLE_ASSERTIONS
+	/*
+	 * It can be dangerous to call this function with an
+	 * out of bounds index.  Ensure `idx` is valid.
+	 */
+	mov	x2, x0
+	lsr	x2, x2, #4
+	cmp	x2, #0
+	ASM_ASSERT(eq)
+#endif
+
+	/*
+	 * Given `idx` calculate address of mrs/ret instruction pair
+	 * in the table below.
+	 */
+	adr	x2, 1f
+	lsl	x0, x0, #3		/* each msr/ret sequence is 8 bytes */
+	add	x2, x2, x0
+	br	x2
+
+1:
+	msr	AMEVCNTR10_EL0, x1	/* index 0 */
+	ret
+	msr	AMEVCNTR11_EL0, x1	/* index 1 */
+	ret
+	msr	AMEVCNTR12_EL0, x1	/* index 2 */
+	ret
+	msr	AMEVCNTR13_EL0, x1	/* index 3 */
+	ret
+	msr	AMEVCNTR14_EL0, x1	/* index 4 */
+	ret
+	msr	AMEVCNTR15_EL0, x1	/* index 5 */
+	ret
+	msr	AMEVCNTR16_EL0, x1	/* index 6 */
+	ret
+	msr	AMEVCNTR17_EL0, x1	/* index 7 */
+	ret
+	msr	AMEVCNTR18_EL0, x1	/* index 8 */
+	ret
+	msr	AMEVCNTR19_EL0, x1	/* index 9 */
+	ret
+	msr	AMEVCNTR1A_EL0, x1	/* index 10 */
+	ret
+	msr	AMEVCNTR1B_EL0, x1	/* index 11 */
+	ret
+	msr	AMEVCNTR1C_EL0, x1	/* index 12 */
+	ret
+	msr	AMEVCNTR1D_EL0, x1	/* index 13 */
+	ret
+	msr	AMEVCNTR1E_EL0, x1	/* index 14 */
+	ret
+	msr	AMEVCNTR1F_EL0, x1	/* index 15 */
+	ret
+endfunc amu_group1_cnt_write_internal
+
+/*
+ * void amu_group1_set_evtype_internal(int idx, unsigned int val);
+ *
+ * Program the AMU event type register indexed by `idx`
+ * with the value `val`.
+ */
+func amu_group1_set_evtype_internal
+#if ENABLE_ASSERTIONS
+	/*
+	 * It can be dangerous to call this function with an
+	 * out of bounds index.  Ensure `idx` is valid.
+	 */
+	mov	x2, x0
+	lsr	x2, x2, #4
+	cmp	x2, #0
+	ASM_ASSERT(eq)
+
+	/* val should be between [0, 65535] */
+	mov	x2, x1
+	lsr	x2, x2, #16
+	cmp	x2, #0
+	ASM_ASSERT(eq)
+#endif
+
+	/*
+	 * Given `idx` calculate address of msr/ret instruction pair
+	 * in the table below.
+	 */
+	adr	x2, 1f
+	lsl	x0, x0, #3		/* each msr/ret sequence is 8 bytes */
+	add	x2, x2, x0
+	br	x2
+
+1:
+	msr	AMEVTYPER10_EL0, x1	/* index 0 */
+	ret
+	msr	AMEVTYPER11_EL0, x1	/* index 1 */
+	ret
+	msr	AMEVTYPER12_EL0, x1	/* index 2 */
+	ret
+	msr	AMEVTYPER13_EL0, x1	/* index 3 */
+	ret
+	msr	AMEVTYPER14_EL0, x1	/* index 4 */
+	ret
+	msr	AMEVTYPER15_EL0, x1	/* index 5 */
+	ret
+	msr	AMEVTYPER16_EL0, x1	/* index 6 */
+	ret
+	msr	AMEVTYPER17_EL0, x1	/* index 7 */
+	ret
+	msr	AMEVTYPER18_EL0, x1	/* index 8 */
+	ret
+	msr	AMEVTYPER19_EL0, x1	/* index 9 */
+	ret
+	msr	AMEVTYPER1A_EL0, x1	/* index 10 */
+	ret
+	msr	AMEVTYPER1B_EL0, x1	/* index 11 */
+	ret
+	msr	AMEVTYPER1C_EL0, x1	/* index 12 */
+	ret
+	msr	AMEVTYPER1D_EL0, x1	/* index 13 */
+	ret
+	msr	AMEVTYPER1E_EL0, x1	/* index 14 */
+	ret
+	msr	AMEVTYPER1F_EL0, x1	/* index 15 */
+	ret
+endfunc amu_group1_set_evtype_internal