• Juan Castillo's avatar
    Call platform_is_primary_cpu() only from reset handler · 53fdcebd
    Juan Castillo authored
    The purpose of platform_is_primary_cpu() is to determine after reset
    (BL1 or BL3-1 with reset handler) if the current CPU must follow the
    cold boot path (primary CPU), or wait in a safe state (secondary CPU)
    until the primary CPU has finished the system initialization.
    
    This patch removes redundant calls to platform_is_primary_cpu() in
    subsequent bootloader entrypoints since the reset handler already
    guarantees that code is executed exclusively on the primary CPU.
    
    Additionally, this patch removes the weak definition of
    platform_is_primary_cpu(), so the implementation of this function
    becomes mandatory. Removing the weak symbol avoids other
    bootloaders accidentally picking up an invalid definition in case the
    porting layer makes the real function available only to BL1.
    
    The define PRIMARY_CPU is no longer mandatory in the platform porting
    because platform_is_primary_cpu() hides the implementation details
    (for instance, there may be platforms that report the primary CPU in
    a system register). The primary CPU definition in FVP has been moved
    to fvp_def.h.
    
    The porting guide has been updated accordingly.
    
    Fixes ARM-software/tf-issues#219
    
    Change-Id: If675a1de8e8d25122b7fef147cb238d939f90b5e
    53fdcebd
bl2_entrypoint.S 3.72 KB
/*
 * Copyright (c) 2013-2014, 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 <asm_macros.S>
#include <bl_common.h>


	.globl	bl2_entrypoint



func bl2_entrypoint
	/*---------------------------------------------
	 * Store the extents of the tzram available to
	 * BL2 for future use. Use the opcode param to
	 * allow implement other functions if needed.
	 * ---------------------------------------------
	 */
	mov	x20, x0
	mov	x21, x1

	/* ---------------------------------------------
	 * Set the exception vector to something sane.
	 * ---------------------------------------------
	 */
	adr	x0, early_exceptions
	msr	vbar_el1, x0

	/* ---------------------------------------------
	 * Enable the instruction cache, stack pointer
	 * and data access alignment checks
	 * ---------------------------------------------
	 */
	mov	x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
	mrs	x0, sctlr_el1
	orr	x0, x0, x1
	msr	sctlr_el1, x0
	isb

	/* ---------------------------------------------
	 * Check the opcodes out of paranoia.
	 * ---------------------------------------------
	 */
	mov	x0, #RUN_IMAGE
	cmp	x0, x20
	b.ne	_panic

	/* ---------------------------------------------
	 * Zero out NOBITS sections. There are 2 of them:
	 *   - the .bss section;
	 *   - the coherent memory section.
	 * ---------------------------------------------
	 */
	ldr	x0, =__BSS_START__
	ldr	x1, =__BSS_SIZE__
	bl	zeromem16

	ldr	x0, =__COHERENT_RAM_START__
	ldr	x1, =__COHERENT_RAM_UNALIGNED_SIZE__
	bl	zeromem16

	/* --------------------------------------------
	 * Allocate a stack whose memory will be marked
	 * as Normal-IS-WBWA when the MMU is enabled.
	 * There is no risk of reading stale stack
	 * memory after enabling the MMU as only the
	 * primary cpu is running at the moment.
	 * --------------------------------------------
	 */
	mrs	x0, mpidr_el1
	bl	platform_set_stack

	/* ---------------------------------------------
	 * Perform early platform setup & platform
	 * specific early arch. setup e.g. mmu setup
	 * ---------------------------------------------
	 */
	mov	x0, x21
	bl	bl2_early_platform_setup
	bl	bl2_plat_arch_setup

	/* ---------------------------------------------
	 * Jump to main function.
	 * ---------------------------------------------
	 */
	bl	bl2_main
_panic:
	b	_panic