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/*
* 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 <stdio.h>
#include <string.h>
#include <assert.h>
#include <arch_helpers.h>
#include <console.h>
#include <platform.h>
#include <semihosting.h>
#include <bl_common.h>
#include <bl31.h>
#include <runtime_svc.h>
#include <context_mgmt.h>
/*******************************************************************************
* Variable to indicate whether next image to execute after BL31 is BL33
* (non-secure & default) or BL32 (secure).
******************************************************************************/
static uint32_t next_image_type = NON_SECURE;
/*******************************************************************************
* Simple function to initialise all BL31 helper libraries.
******************************************************************************/
void bl31_lib_init()
{
cm_init();
}
/*******************************************************************************
* BL31 is responsible for setting up the runtime services for the primary cpu
* before passing control to the bootloader or an Operating System. This
* function calls runtime_svc_init() which initializes all registered runtime
* services. The run time services would setup enough context for the core to
* swtich to the next exception level. When this function returns, the core will
* switch to the programmed exception level via. an ERET.
******************************************************************************/
void bl31_main(void)
{
#if DEBUG
unsigned long mpidr = read_mpidr();
#endif
/* Perform remaining generic architectural setup from EL3 */
bl31_arch_setup();
/* Perform platform setup in BL1 */
bl31_platform_setup();
#if defined (__GNUC__)
printf("BL31 Built : %s, %s\n\r", __TIME__, __DATE__);
#endif
/* Initialise helper libraries */
bl31_lib_init();
/* Initialize the runtime services e.g. psci */
runtime_svc_init();
/* Clean caches before re-entering normal world */
dcsw_op_all(DCCSW);
/*
* Use the more complex exception vectors now that context
* management is setup. SP_EL3 should point to a 'cpu_context'
* structure which has an exception stack allocated. The PSCI
* service should have set the context.
*/
assert(cm_get_context(mpidr, NON_SECURE));
cm_set_next_eret_context(NON_SECURE);
write_vbar_el3((uint64_t) runtime_exceptions);
/*
* All the cold boot actions on the primary cpu are done. We
* now need to decide which is the next image (BL32 or BL33)
* and how to execute it. If the SPD runtime service is
* present, it would want to pass control to BL32 first in
* S-EL1. It will export the bl32_init() routine where it takes
* responsibility of entering S-EL1 and returning control back
* to bl31_main. Once this is done we can prepare entry into
* BL33 as normal.
*/
/* Tell BL32 about it memory extents as well */
if (bl32_init)
bl32_init(bl31_plat_get_bl32_mem_layout());
/*
* We are ready to enter the next EL. Prepare entry into the image
* corresponding to the desired security state after the next ERET.
*/
bl31_prepare_next_image_entry();
}
/*******************************************************************************
* Accessor functions to help runtime services decide which image should be
* executed after BL31. This is BL33 or the non-secure bootloader image by
* default but the Secure payload dispatcher could override this by requesting
* an entry into BL32 (Secure payload) first. If it does so then it should use
* the same API to program an entry into BL33 once BL32 initialisation is
* complete.
******************************************************************************/
void bl31_set_next_image_type(uint32_t security_state)
{
assert(security_state == NON_SECURE || security_state == SECURE);
next_image_type = security_state;
}
uint32_t bl31_get_next_image_type(void)
{
return next_image_type;
}
/*******************************************************************************
* This function programs EL3 registers and performs other setup to enable entry
* into the next image after BL31 at the next ERET.
******************************************************************************/
void bl31_prepare_next_image_entry()
{
el_change_info *next_image_info;
uint32_t scr, image_type;
/* Determine which image to execute next */
image_type = bl31_get_next_image_type();
/*
* Setup minimal architectural state of the next highest EL to
* allow execution in it immediately upon entering it.
*/
bl31_next_el_arch_setup(image_type);
/* Program EL3 registers to enable entry into the next EL */
next_image_info = bl31_get_next_image_info(image_type);
assert(next_image_info);
scr = read_scr();
if (image_type == NON_SECURE)
scr |= SCR_NS_BIT;
/*
* Tell the context mgmt. library to ensure that SP_EL3 points to
* the right context to exit from EL3 correctly.
*/
cm_set_el3_eret_context(next_image_info->security_state,
next_image_info->entrypoint,
next_image_info->spsr,
scr);
/* Finally set the next context */
cm_set_next_eret_context(next_image_info->security_state);
}
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