Add initial CPU support for Cortex-Helios

Change-Id: Ic0486131c493632eadf329f80b0b5904aed5e4ef
Signed-off-by: Joel Hutton <joel.hutton@arm.com>
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

include/lib/cpus/aarch64/cortex_helios.h

+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __CORTEX_HELIOS_H__
+#define __CORTEX_HELIOS_H__
+
+#define CORTEX_HELIOS_MIDR		U(0x410FD060)
+
+/*******************************************************************************
+ * CPU Extended Control register specific definitions.
+ ******************************************************************************/
+#define CORTEX_HELIOS_ECTLR_EL1		S3_0_C15_C1_4
+
+/*******************************************************************************
+ * CPU Auxiliary Control register specific definitions.
+ ******************************************************************************/
+#define CORTEX_HELIOS_CPUACTLR_EL1	S3_0_C15_C1_0
+
+/*******************************************************************************
+ * CPU Power Control register specific definitions.
+ ******************************************************************************/
+
+#define CORTEX_HELIOS_CPUPWRCTLR_EL1				S3_0_C15_C2_7
+#define CORTEX_HELIOS_CPUPWRCTLR_EL1_CORE_PWRDN_BIT		(U(1) << 0)
+
+#endif /* __CORTEX_HELIOS_H__ */

lib/cpus/aarch64/cortex_helios.S

+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <arch.h>
+#include <asm_macros.S>
+#include <bl_common.h>
+#include <cortex_helios.h>
+#include <cpu_macros.S>
+#include <debug.h>
+#include <plat_macros.S>
+
+func cortex_helios_cpu_pwr_dwn
+	mrs	x0, CORTEX_HELIOS_CPUPWRCTLR_EL1
+	orr	x0, x0, #CORTEX_HELIOS_CPUPWRCTLR_EL1_CORE_PWRDN_BIT
+	msr	CORTEX_HELIOS_CPUPWRCTLR_EL1, x0
+	isb
+	ret
+endfunc cortex_helios_cpu_pwr_dwn
+
+.section .rodata.cortex_helios_regs, "aS"
+cortex_helios_regs:  /* The ascii list of register names to be reported */
+	.asciz	"cpuectlr_el1", ""
+
+func cortex_helios_cpu_reg_dump
+	adr	x6, cortex_helios_regs
+	mrs	x8, CORTEX_HELIOS_ECTLR_EL1
+	ret
+endfunc cortex_helios_cpu_reg_dump
+
+declare_cpu_ops cortex_helios, CORTEX_HELIOS_MIDR, \
+	CPU_NO_RESET_FUNC, \
+	cortex_helios_cpu_pwr_dwn