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      1 /*
      2  * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are met:
      6  *
      7  * Redistributions of source code must retain the above copyright notice, this
      8  * list of conditions and the following disclaimer.
      9  *
     10  * Redistributions in binary form must reproduce the above copyright notice,
     11  * this list of conditions and the following disclaimer in the documentation
     12  * and/or other materials provided with the distribution.
     13  *
     14  * Neither the name of ARM nor the names of its contributors may be used
     15  * to endorse or promote products derived from this software without specific
     16  * prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
     22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     28  * POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include <arch.h>
     32 #include <arch_helpers.h>
     33 #include <assert.h>
     34 #include <bl_common.h>
     35 #include <bl31.h>
     36 #include <context_mgmt.h>
     37 #include <debug.h>
     38 #include <platform.h>
     39 #include <runtime_svc.h>
     40 #include <string.h>
     41 
     42 /*******************************************************************************
     43  * This function pointer is used to initialise the BL32 image. It's initialized
     44  * by SPD calling bl31_register_bl32_init after setting up all things necessary
     45  * for SP execution. In cases where both SPD and SP are absent, or when SPD
     46  * finds it impossible to execute SP, this pointer is left as NULL
     47  ******************************************************************************/
     48 static int32_t (*bl32_init)(void);
     49 
     50 /*******************************************************************************
     51  * Variable to indicate whether next image to execute after BL31 is BL33
     52  * (non-secure & default) or BL32 (secure).
     53  ******************************************************************************/
     54 static uint32_t next_image_type = NON_SECURE;
     55 
     56 /*******************************************************************************
     57  * Simple function to initialise all BL31 helper libraries.
     58  ******************************************************************************/
     59 void bl31_lib_init(void)
     60 {
     61 	cm_init();
     62 }
     63 
     64 /*******************************************************************************
     65  * BL31 is responsible for setting up the runtime services for the primary cpu
     66  * before passing control to the bootloader or an Operating System. This
     67  * function calls runtime_svc_init() which initializes all registered runtime
     68  * services. The run time services would setup enough context for the core to
     69  * swtich to the next exception level. When this function returns, the core will
     70  * switch to the programmed exception level via. an ERET.
     71  ******************************************************************************/
     72 void bl31_main(void)
     73 {
     74 	NOTICE("BL3-1: %s\n", version_string);
     75 	NOTICE("BL3-1: %s\n", build_message);
     76 
     77 	/* Perform remaining generic architectural setup from EL3 */
     78 	bl31_arch_setup();
     79 
     80 	/* Perform platform setup in BL1 */
     81 	bl31_platform_setup();
     82 
     83 	/* Initialise helper libraries */
     84 	bl31_lib_init();
     85 
     86 	/* Initialize the runtime services e.g. psci */
     87 	INFO("BL3-1: Initializing runtime services\n");
     88 	runtime_svc_init();
     89 
     90 	/* Clean caches before re-entering normal world */
     91 	dcsw_op_all(DCCSW);
     92 
     93 	/*
     94 	 * All the cold boot actions on the primary cpu are done. We now need to
     95 	 * decide which is the next image (BL32 or BL33) and how to execute it.
     96 	 * If the SPD runtime service is present, it would want to pass control
     97 	 * to BL32 first in S-EL1. In that case, SPD would have registered a
     98 	 * function to intialize bl32 where it takes responsibility of entering
     99 	 * S-EL1 and returning control back to bl31_main. Once this is done we
    100 	 * can prepare entry into BL33 as normal.
    101 	 */
    102 
    103 	/*
    104 	 * If SPD had registerd an init hook, invoke it.
    105 	 */
    106 	if (bl32_init) {
    107 		INFO("BL3-1: Initializing BL3-2\n");
    108 		(*bl32_init)();
    109 	}
    110 	/*
    111 	 * We are ready to enter the next EL. Prepare entry into the image
    112 	 * corresponding to the desired security state after the next ERET.
    113 	 */
    114 	bl31_prepare_next_image_entry();
    115 }
    116 
    117 /*******************************************************************************
    118  * Accessor functions to help runtime services decide which image should be
    119  * executed after BL31. This is BL33 or the non-secure bootloader image by
    120  * default but the Secure payload dispatcher could override this by requesting
    121  * an entry into BL32 (Secure payload) first. If it does so then it should use
    122  * the same API to program an entry into BL33 once BL32 initialisation is
    123  * complete.
    124  ******************************************************************************/
    125 void bl31_set_next_image_type(uint32_t security_state)
    126 {
    127 	assert(sec_state_is_valid(security_state));
    128 	next_image_type = security_state;
    129 }
    130 
    131 uint32_t bl31_get_next_image_type(void)
    132 {
    133 	return next_image_type;
    134 }
    135 
    136 /*******************************************************************************
    137  * This function programs EL3 registers and performs other setup to enable entry
    138  * into the next image after BL31 at the next ERET.
    139  ******************************************************************************/
    140 void bl31_prepare_next_image_entry(void)
    141 {
    142 	entry_point_info_t *next_image_info;
    143 	uint32_t image_type;
    144 
    145 	/* Determine which image to execute next */
    146 	image_type = bl31_get_next_image_type();
    147 
    148 	/* Program EL3 registers to enable entry into the next EL */
    149 	next_image_info = bl31_plat_get_next_image_ep_info(image_type);
    150 	assert(next_image_info);
    151 	assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
    152 
    153 	INFO("BL3-1: Preparing for EL3 exit to %s world\n",
    154 		(image_type == SECURE) ? "secure" : "normal");
    155 	INFO("BL3-1: Next image address = 0x%llx\n",
    156 		(unsigned long long) next_image_info->pc);
    157 	INFO("BL3-1: Next image spsr = 0x%x\n", next_image_info->spsr);
    158 	cm_init_context(read_mpidr_el1(), next_image_info);
    159 	cm_prepare_el3_exit(image_type);
    160 }
    161 
    162 /*******************************************************************************
    163  * This function initializes the pointer to BL32 init function. This is expected
    164  * to be called by the SPD after it finishes all its initialization
    165  ******************************************************************************/
    166 void bl31_register_bl32_init(int32_t (*func)(void))
    167 {
    168 	bl32_init = func;
    169 }
    170