• Andrew Thoelke's avatar
    Set processor endianness immediately after RESET · 40fd0725
    Andrew Thoelke authored
    SCTLR_EL3.EE is being configured too late in bl1_arch_setup() and
    bl31_arch_setup() after data accesses have already occured on
    the cold and warm boot paths.
    
    This control bit must be configured immediately on CPU reset to
    match the endian state of the firmware (little endian).
    
    Fixes ARM-software/tf-issues#145
    
    Change-Id: Ie12e46fbbed6baf024c30beb50751591bb8c8655
    40fd0725
bl31_arch_setup.c 3.79 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 <arch_helpers.h>
#include <assert.h>
#include <bl_common.h>
#include <bl31.h>
#include <platform.h>

/*******************************************************************************
 * This duplicates what the primary cpu did after a cold boot in BL1. The same
 * needs to be done when a cpu is hotplugged in. This function could also over-
 * ride any EL3 setup done by BL1 as this code resides in rw memory.
 ******************************************************************************/
void bl31_arch_setup(void)
{
	unsigned long tmp_reg = 0;
	uint64_t counter_freq;

	/* Enable alignment checks */
	tmp_reg = read_sctlr_el3();
	tmp_reg |= (SCTLR_A_BIT | SCTLR_SA_BIT);
	write_sctlr_el3(tmp_reg);

	/*
	 * Enable HVCs, route FIQs to EL3, set the next EL to be AArch64, route
	 * external abort and SError interrupts to EL3
	 */
	tmp_reg = SCR_RES1_BITS | SCR_RW_BIT | SCR_HCE_BIT | SCR_EA_BIT |
		  SCR_FIQ_BIT;
	write_scr(tmp_reg);

	/*
	 * Enable SError and Debug exceptions
	 */
	enable_serror();
	enable_debug_exceptions();

	/* Program the counter frequency */
	counter_freq = plat_get_syscnt_freq();
	write_cntfrq_el0(counter_freq);
}

/*******************************************************************************
 * Detect what the security state of the next EL is and setup the minimum
 * required architectural state: program SCTRL to reflect the RES1 bits, and to
 * have MMU and caches disabled
 ******************************************************************************/
void bl31_next_el_arch_setup(uint32_t security_state)
{
	unsigned long id_aa64pfr0 = read_id_aa64pfr0_el1();
	unsigned long next_sctlr;
	unsigned long el_status;
	unsigned long scr = read_scr();

	/* Use the same endianness than the current BL */
	next_sctlr = (read_sctlr_el3() & SCTLR_EE_BIT);

	/* Find out which EL we are going to */
	el_status = (id_aa64pfr0 >> ID_AA64PFR0_EL2_SHIFT) & ID_AA64PFR0_ELX_MASK;

	if (security_state == NON_SECURE) {
		/* Check if EL2 is supported */
		if (el_status && (scr & SCR_HCE_BIT)) {
			/* Set SCTLR EL2 */
			next_sctlr |= SCTLR_EL2_RES1;
			write_sctlr_el2(next_sctlr);
			return;
		}
	}

	/*
	 * SCTLR_EL1 needs the same programming irrespective of the
	 * security state of EL1.
	 */
	next_sctlr |= SCTLR_EL1_RES1;
	write_sctlr_el1(next_sctlr);
}