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