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      1 /*
      2  * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
      3  *
      4  * SPDX-License-Identifier: BSD-3-Clause
      5  */
      6 
      7 #include <arch.h>
      8 #include <arch_helpers.h>
      9 #include <assert.h>
     10 #include <bl31.h>
     11 #include <bl_common.h>
     12 #include <console.h>
     13 #include <context_mgmt.h>
     14 #include <debug.h>
     15 #include <platform.h>
     16 #include <pmf.h>
     17 #include <runtime_instr.h>
     18 #include <runtime_svc.h>
     19 #include <string.h>
     20 
     21 #if ENABLE_RUNTIME_INSTRUMENTATION
     22 PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
     23 	RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
     24 #endif
     25 
     26 /*******************************************************************************
     27  * This function pointer is used to initialise the BL32 image. It's initialized
     28  * by SPD calling bl31_register_bl32_init after setting up all things necessary
     29  * for SP execution. In cases where both SPD and SP are absent, or when SPD
     30  * finds it impossible to execute SP, this pointer is left as NULL
     31  ******************************************************************************/
     32 static int32_t (*bl32_init)(void);
     33 
     34 /*******************************************************************************
     35  * Variable to indicate whether next image to execute after BL31 is BL33
     36  * (non-secure & default) or BL32 (secure).
     37  ******************************************************************************/
     38 static uint32_t next_image_type = NON_SECURE;
     39 
     40 /*
     41  * Implement the ARM Standard Service function to get arguments for a
     42  * particular service.
     43  */
     44 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
     45 {
     46 	/* Setup the arguments for PSCI Library */
     47 	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
     48 
     49 	/* PSCI is the only ARM Standard Service implemented */
     50 	assert(svc_mask == PSCI_FID_MASK);
     51 
     52 	return (uintptr_t)&psci_args;
     53 }
     54 
     55 /*******************************************************************************
     56  * Simple function to initialise all BL31 helper libraries.
     57  ******************************************************************************/
     58 void bl31_lib_init(void)
     59 {
     60 	cm_init();
     61 }
     62 
     63 /*******************************************************************************
     64  * BL31 is responsible for setting up the runtime services for the primary cpu
     65  * before passing control to the bootloader or an Operating System. This
     66  * function calls runtime_svc_init() which initializes all registered runtime
     67  * services. The run time services would setup enough context for the core to
     68  * swtich to the next exception level. When this function returns, the core will
     69  * switch to the programmed exception level via. an ERET.
     70  ******************************************************************************/
     71 void bl31_main(void)
     72 {
     73 	NOTICE("BL31: %s\n", version_string);
     74 	NOTICE("BL31: %s\n", build_message);
     75 
     76 	/* Perform platform setup in BL31 */
     77 	bl31_platform_setup();
     78 
     79 	/* Initialise helper libraries */
     80 	bl31_lib_init();
     81 
     82 	/* Initialize the runtime services e.g. psci. */
     83 	INFO("BL31: Initializing runtime services\n");
     84 	runtime_svc_init();
     85 
     86 	/*
     87 	 * All the cold boot actions on the primary cpu are done. We now need to
     88 	 * decide which is the next image (BL32 or BL33) and how to execute it.
     89 	 * If the SPD runtime service is present, it would want to pass control
     90 	 * to BL32 first in S-EL1. In that case, SPD would have registered a
     91 	 * function to intialize bl32 where it takes responsibility of entering
     92 	 * S-EL1 and returning control back to bl31_main. Once this is done we
     93 	 * can prepare entry into BL33 as normal.
     94 	 */
     95 
     96 	/*
     97 	 * If SPD had registerd an init hook, invoke it.
     98 	 */
     99 	if (bl32_init) {
    100 		INFO("BL31: Initializing BL32\n");
    101 		(*bl32_init)();
    102 	}
    103 	/*
    104 	 * We are ready to enter the next EL. Prepare entry into the image
    105 	 * corresponding to the desired security state after the next ERET.
    106 	 */
    107 	bl31_prepare_next_image_entry();
    108 
    109 	console_flush();
    110 
    111 	/*
    112 	 * Perform any platform specific runtime setup prior to cold boot exit
    113 	 * from BL31
    114 	 */
    115 	bl31_plat_runtime_setup();
    116 }
    117 
    118 /*******************************************************************************
    119  * Accessor functions to help runtime services decide which image should be
    120  * executed after BL31. This is BL33 or the non-secure bootloader image by
    121  * default but the Secure payload dispatcher could override this by requesting
    122  * an entry into BL32 (Secure payload) first. If it does so then it should use
    123  * the same API to program an entry into BL33 once BL32 initialisation is
    124  * complete.
    125  ******************************************************************************/
    126 void bl31_set_next_image_type(uint32_t security_state)
    127 {
    128 	assert(sec_state_is_valid(security_state));
    129 	next_image_type = security_state;
    130 }
    131 
    132 uint32_t bl31_get_next_image_type(void)
    133 {
    134 	return next_image_type;
    135 }
    136 
    137 /*******************************************************************************
    138  * This function programs EL3 registers and performs other setup to enable entry
    139  * into the next image after BL31 at the next ERET.
    140  ******************************************************************************/
    141 void bl31_prepare_next_image_entry(void)
    142 {
    143 	entry_point_info_t *next_image_info;
    144 	uint32_t image_type;
    145 
    146 #if CTX_INCLUDE_AARCH32_REGS
    147 	/*
    148 	 * Ensure that the build flag to save AArch32 system registers in CPU
    149 	 * context is not set for AArch64-only platforms.
    150 	 */
    151 	if (EL_IMPLEMENTED(1) == EL_IMPL_A64ONLY) {
    152 		ERROR("EL1 supports AArch64-only. Please set build flag "
    153 				"CTX_INCLUDE_AARCH32_REGS = 0");
    154 		panic();
    155 	}
    156 #endif
    157 
    158 	/* Determine which image to execute next */
    159 	image_type = bl31_get_next_image_type();
    160 
    161 	/* Program EL3 registers to enable entry into the next EL */
    162 	next_image_info = bl31_plat_get_next_image_ep_info(image_type);
    163 	assert(next_image_info);
    164 	assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
    165 
    166 	INFO("BL31: Preparing for EL3 exit to %s world\n",
    167 		(image_type == SECURE) ? "secure" : "normal");
    168 	print_entry_point_info(next_image_info);
    169 	cm_init_my_context(next_image_info);
    170 	cm_prepare_el3_exit(image_type);
    171 }
    172 
    173 /*******************************************************************************
    174  * This function initializes the pointer to BL32 init function. This is expected
    175  * to be called by the SPD after it finishes all its initialization
    176  ******************************************************************************/
    177 void bl31_register_bl32_init(int32_t (*func)(void))
    178 {
    179 	bl32_init = func;
    180 }
    181