diff --git a/lib/cpus/aarch64/rainier.S b/lib/cpus/aarch64/rainier.S
new file mode 100644
index 0000000..f7afd0b
--- /dev/null
+++ b/lib/cpus/aarch64/rainier.S
@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <context.h>
+#include <cpu_macros.S>
+#include <cpuamu.h>
+#include <rainier.h>
+
+/* Hardware handled coherency */
+#if HW_ASSISTED_COHERENCY == 0
+#error "Rainier CPU must be compiled with HW_ASSISTED_COHERENCY enabled"
+#endif
+
+/* 64-bit only core */
+#if CTX_INCLUDE_AARCH32_REGS == 1
+#error "Rainier CPU supports only AArch64. Compile with CTX_INCLUDE_AARCH32_REGS=0"
+#endif
+
+#if ERRATA_RAINIER_IC_TRAP
+	.global rainier_errata_ic_trap_handler
+#endif
+
+/* --------------------------------------------------
+ * Disable speculative loads if Rainier supports
+ * SSBS.
+ *
+ * Shall clobber: x0.
+ * --------------------------------------------------
+ */
+func rainier_disable_speculative_loads
+	/* Check if the PE implements SSBS */
+	mrs	x0, id_aa64pfr1_el1
+	tst	x0, #(ID_AA64PFR1_EL1_SSBS_MASK << ID_AA64PFR1_EL1_SSBS_SHIFT)
+	b.eq	1f
+
+	/* Disable speculative loads */
+	msr	SSBS, xzr
+
+1:
+	ret
+endfunc rainier_disable_speculative_loads
+
+/* --------------------------------------------------
+ * Errata Workaround for Neoverse N1 Erratum 1542419.
+ * This applies to revisions r3p0 - r4p0 of Neoverse N1
+ * Since Rainier core is based on Neoverse N1 r4p0, this
+ * errata applies to Rainier core r0p0
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_n1_1542419_wa
+	/* Compare x0 against revision r3p0 and r4p0 */
+	mov	x17, x30
+	bl	check_errata_1542419
+	cbz	x0, 1f
+
+        /* Apply instruction patching sequence */
+	mov	x0, xzr
+	msr	CPUPSELR_EL3, x0
+	ldr	x0, =0xEE670D35
+	msr	CPUPOR_EL3, x0
+	ldr	x0, =0xFFFF0FFF
+	msr	CPUPMR_EL3, x0
+	ldr	x0, =0x08000020007D
+	msr	CPUPCR_EL3, x0
+	isb
+1:
+	ret	x17
+endfunc errata_n1_1542419_wa
+
+func check_errata_1542419
+	/* Applies to Rainier core r0p0. */
+	mov	x1, #0x00
+	b	cpu_rev_var_ls
+endfunc check_errata_1542419
+
+func rainier_reset_func
+	mov	x19, x30
+
+	bl	rainier_disable_speculative_loads
+
+	/* Forces all cacheable atomic instructions to be near */
+	mrs	x0, RAINIER_CPUACTLR2_EL1
+	orr	x0, x0, #RAINIER_CPUACTLR2_EL1_BIT_2
+	msr	RAINIER_CPUACTLR2_EL1, x0
+	isb
+
+	bl	cpu_get_rev_var
+	mov	x18, x0
+
+#if ERRATA_N1_1542419
+	mov	x0, x18
+	bl	errata_n1_1542419_wa
+#endif
+
+#if ENABLE_AMU
+	/* Make sure accesses from EL0/EL1 and EL2 are not trapped to EL3 */
+	mrs	x0, actlr_el3
+	orr	x0, x0, #RAINIER_ACTLR_AMEN_BIT
+	msr	actlr_el3, x0
+
+	/* Make sure accesses from EL0/EL1 are not trapped to EL2 */
+	mrs	x0, actlr_el2
+	orr	x0, x0, #RAINIER_ACTLR_AMEN_BIT
+	msr	actlr_el2, x0
+
+	/* Enable group0 counters */
+	mov	x0, #RAINIER_AMU_GROUP0_MASK
+	msr	CPUAMCNTENSET_EL0, x0
+#endif
+
+	isb
+	ret	x19
+endfunc rainier_reset_func
+
+	/* ---------------------------------------------
+	 * HW will do the cache maintenance while powering down
+	 * ---------------------------------------------
+	 */
+func rainier_core_pwr_dwn
+	/* ---------------------------------------------
+	 * Enable CPU power down bit in power control register
+	 * ---------------------------------------------
+	 */
+	mrs	x0, RAINIER_CPUPWRCTLR_EL1
+	orr	x0, x0, #RAINIER_CORE_PWRDN_EN_MASK
+	msr	RAINIER_CPUPWRCTLR_EL1, x0
+	isb
+	ret
+endfunc rainier_core_pwr_dwn
+
+#if REPORT_ERRATA
+/*
+ * Errata printing function for Rainier. Must follow AAPCS.
+ */
+func rainier_errata_report
+	stp	x8, x30, [sp, #-16]!
+
+	bl	cpu_get_rev_var
+	mov	x8, x0
+
+	/*
+	 * Report all errata. The revision-variant information is passed to
+	 * checking functions of each errata.
+	 */
+	report_errata ERRATA_N1_1542419, rainier, 1542419
+
+	ldp	x8, x30, [sp], #16
+	ret
+endfunc rainier_errata_report
+#endif
+
+/*
+ * Handle trap of EL0 IC IVAU instructions to EL3 by executing a TLB
+ * inner-shareable invalidation to an arbitrary address followed by a DSB.
+ *
+ * x1: Exception Syndrome
+ */
+func rainier_errata_ic_trap_handler
+	cmp	x1, #RAINIER_EC_IC_TRAP
+	b.ne	1f
+	tlbi	vae3is, xzr
+	dsb	sy
+
+        # Skip the IC instruction itself
+        mrs     x3, elr_el3
+        add     x3, x3, #4
+        msr     elr_el3, x3
+
+	ldp	x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
+	ldp	x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
+	ldp	x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
+	ldr	x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+
+#if IMAGE_BL31 && RAS_EXTENSION
+	/*
+	 * Issue Error Synchronization Barrier to synchronize SErrors before
+	 * exiting EL3. We're running with EAs unmasked, so any synchronized
+	 * errors would be taken immediately; therefore no need to inspect
+	 * DISR_EL1 register.
+	 */
+	esb
+#endif
+	eret
+1:
+	ret
+endfunc rainier_errata_ic_trap_handler
+
+	/* ---------------------------------------------
+	 * This function provides Rainier specific
+	 * register information for crash reporting.
+	 * It needs to return with x6 pointing to
+	 * a list of register names in ascii and
+	 * x8 - x15 having values of registers to be
+	 * reported.
+	 * ---------------------------------------------
+	 */
+.section .rodata.rainier_regs, "aS"
+rainier_regs:  /* The ascii list of register names to be reported */
+	.asciz	"cpuectlr_el1", ""
+
+func rainier_cpu_reg_dump
+	adr	x6, rainier_regs
+	mrs	x8, RAINIER_CPUECTLR_EL1
+	ret
+endfunc rainier_cpu_reg_dump
+
+declare_cpu_ops_eh rainier, RAINIER_MIDR, \
+	rainier_reset_func, \
+	rainier_errata_ic_trap_handler, \
+	rainier_core_pwr_dwn