• Sandrine Bailleux's avatar
    Introduce PROGRAMMABLE_RESET_ADDRESS build option · bf031bba
    Sandrine Bailleux authored
    This patch introduces a new platform build option, called
    PROGRAMMABLE_RESET_ADDRESS, which tells whether the platform has
    a programmable or fixed reset vector address.
    
    If the reset vector address is fixed then the code relies on the
    platform_get_entrypoint() mailbox mechanism to figure out where
    it is supposed to jump. On the other hand, if it is programmable
    then it is assumed that the platform code will program directly
    the right address into the RVBAR register (instead of using the
    mailbox redirection) so the mailbox is ignored in this case.
    
    Change-Id: If59c3b11fb1f692976e1d8b96c7e2da0ebfba308
    bf031bba
bl31_entrypoint.S 4.41 KB
/*
 * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of ARM nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch.h>
#include <bl_common.h>
#include <el3_common_macros.S>

	.globl	bl31_entrypoint


	/* -----------------------------------------------------
	 * bl31_entrypoint() is the cold boot entrypoint,
	 * executed only by the primary cpu.
	 * -----------------------------------------------------
	 */

func bl31_entrypoint
#if !RESET_TO_BL31
	/* ---------------------------------------------------------------
	 * Preceding bootloader has populated x0 with a pointer to a
	 * 'bl31_params' structure & x1 with a pointer to platform
	 * specific structure
	 * ---------------------------------------------------------------
	 */
	mov	x20, x0
	mov	x21, x1

	/* ---------------------------------------------------------------------
	 * For !RESET_TO_BL31 systems, only the primary CPU ever reaches
	 * bl31_entrypoint() during the cold boot flow, so the cold/warm boot
	 * and primary/secondary CPU logic should not be executed in this case.
	 *
	 * Also, assume that the previous bootloader has already set up the CPU
	 * endianness and has initialised the memory.
	 * ---------------------------------------------------------------------
	 */
	el3_entrypoint_common					\
		_set_endian=0					\
		_warm_boot_mailbox=0				\
		_secondary_cold_boot=0				\
		_init_memory=0					\
		_init_c_runtime=1				\
		_exception_vectors=runtime_exceptions

	/* ---------------------------------------------------------------------
	 * Relay the previous bootloader's arguments to the platform layer
	 * ---------------------------------------------------------------------
	 */
	mov	x0, x20
	mov	x1, x21
#else
	/* ---------------------------------------------------------------------
	 * For RESET_TO_BL31 systems which have a programmable reset address,
	 * bl31_entrypoint() is executed only on the cold boot path so we can
	 * skip the warm boot mailbox mechanism.
	 * ---------------------------------------------------------------------
	 */
	el3_entrypoint_common					\
		_set_endian=1					\
		_warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS	\
		_secondary_cold_boot=1				\
		_init_memory=1					\
		_init_c_runtime=1				\
		_exception_vectors=runtime_exceptions

	/* ---------------------------------------------------------------------
	 * For RESET_TO_BL31 systems, BL3-1 is the first bootloader to run so
	 * there's no argument to relay from a previous bootloader. Zero the
	 * arguments passed to the platform layer to reflect that.
	 * ---------------------------------------------------------------------
	 */
	mov	x0, 0
	mov	x1, 0
#endif /* RESET_TO_BL31 */

	/* ---------------------------------------------
	 * Perform platform specific early arch. setup
	 * ---------------------------------------------
	 */
	bl	bl31_early_platform_setup
	bl	bl31_plat_arch_setup

	/* ---------------------------------------------
	 * Jump to main function.
	 * ---------------------------------------------
	 */
	bl	bl31_main

	b	el3_exit
endfunc bl31_entrypoint