bl31/bl31_main.c

   1 /*
   2  * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  */
   6
   7 #include <assert.h>
   8 #include <string.h>
   9
  10 #include <arch.h>
  11 #include <arch_helpers.h>
  12 #include <bl31/bl31.h>
  13 #include <bl31/ehf.h>
  14 #include <common/bl_common.h>
  15 #include <common/debug.h>
  16 #include <common/runtime_svc.h>
  17 #include <drivers/console.h>
  18 #include <lib/el3_runtime/context_mgmt.h>
  19 #include <lib/pmf/pmf.h>
  20 #include <lib/runtime_instr.h>
  21 #include <plat/common/platform.h>
  22 #include <services/std_svc.h>
  23
  24 #if ENABLE_RUNTIME_INSTRUMENTATION
  25 PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
  26         RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
  27 #endif
  28
  29 /*******************************************************************************
  30  * This function pointer is used to initialise the BL32 image. It's initialized
  31  * by SPD calling bl31_register_bl32_init after setting up all things necessary
  32  * for SP execution. In cases where both SPD and SP are absent, or when SPD
  33  * finds it impossible to execute SP, this pointer is left as NULL
  34  ******************************************************************************/
  35 static int32_t (*bl32_init)(void);
  36
  37 /*******************************************************************************
  38  * Variable to indicate whether next image to execute after BL31 is BL33
  39  * (non-secure & default) or BL32 (secure).
  40  ******************************************************************************/
  41 static uint32_t next_image_type = NON_SECURE;
  42
  43 /*
  44  * Implement the ARM Standard Service function to get arguments for a
  45  * particular service.
  46  */
  47 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
  48 {
  49         /* Setup the arguments for PSCI Library */
  50         DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
  51
  52         /* PSCI is the only ARM Standard Service implemented */
  53         assert(svc_mask == PSCI_FID_MASK);
  54
  55         return (uintptr_t)&psci_args;
  56 }
  57
  58 /*******************************************************************************
  59  * Simple function to initialise all BL31 helper libraries.
  60  ******************************************************************************/
  61 void __init bl31_lib_init(void)
  62 {
  63         cm_init();
  64 }
  65
  66 /*******************************************************************************
  67  * Setup function for BL31.
  68  ******************************************************************************/
  69 void bl31_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
  70                 u_register_t arg3)
  71 {
  72         /* Perform early platform-specific setup */
  73         bl31_early_platform_setup2(arg0, arg1, arg2, arg3);
  74
  75         /*
  76          * Update pointer authentication key before the MMU is enabled. It is
  77          * saved in the rodata section, that can be writen before enabling the
  78          * MMU. This function must be called after the console is initialized
  79          * in the early platform setup.
  80          */
  81         bl_handle_pauth();
  82
  83         /* Perform late platform-specific setup */
  84         bl31_plat_arch_setup();
  85 }
  86
  87 /*******************************************************************************
  88  * BL31 is responsible for setting up the runtime services for the primary cpu
  89  * before passing control to the bootloader or an Operating System. This
  90  * function calls runtime_svc_init() which initializes all registered runtime
  91  * services. The run time services would setup enough context for the core to
  92  * switch to the next exception level. When this function returns, the core will
  93  * switch to the programmed exception level via an ERET.
  94  ******************************************************************************/
  95 void bl31_main(void)
  96 {
  97         NOTICE("BL31: %s\n", version_string);
  98         NOTICE("BL31: %s\n", build_message);
  99
 100         /* Perform platform setup in BL31 */
 101         bl31_platform_setup();
 102
 103         /* Initialise helper libraries */
 104         bl31_lib_init();
 105
 106 #if EL3_EXCEPTION_HANDLING
 107         INFO("BL31: Initialising Exception Handling Framework\n");
 108         ehf_init();
 109 #endif
 110
 111         /* Initialize the runtime services e.g. psci. */
 112         INFO("BL31: Initializing runtime services\n");
 113         runtime_svc_init();
 114
 115         /*
 116          * All the cold boot actions on the primary cpu are done. We now need to
 117          * decide which is the next image (BL32 or BL33) and how to execute it.
 118          * If the SPD runtime service is present, it would want to pass control
 119          * to BL32 first in S-EL1. In that case, SPD would have registered a
 120          * function to initialize bl32 where it takes responsibility of entering
 121          * S-EL1 and returning control back to bl31_main. Once this is done we
 122          * can prepare entry into BL33 as normal.
 123          */
 124
 125         /*
 126          * If SPD had registered an init hook, invoke it.
 127          */
 128         if (bl32_init != NULL) {
 129                 INFO("BL31: Initializing BL32\n");
 130
 131                 int32_t rc = (*bl32_init)();
 132
 133                 if (rc == 0)
 134                         WARN("BL31: BL32 initialization failed\n");
 135         }
 136         /*
 137          * We are ready to enter the next EL. Prepare entry into the image
 138          * corresponding to the desired security state after the next ERET.
 139          */
 140         bl31_prepare_next_image_entry();
 141
 142         console_flush();
 143
 144         /*
 145          * Perform any platform specific runtime setup prior to cold boot exit
 146          * from BL31
 147          */
 148         bl31_plat_runtime_setup();
 149 }
 150
 151 /*******************************************************************************
 152  * Accessor functions to help runtime services decide which image should be
 153  * executed after BL31. This is BL33 or the non-secure bootloader image by
 154  * default but the Secure payload dispatcher could override this by requesting
 155  * an entry into BL32 (Secure payload) first. If it does so then it should use
 156  * the same API to program an entry into BL33 once BL32 initialisation is
 157  * complete.
 158  ******************************************************************************/
 159 void bl31_set_next_image_type(uint32_t security_state)
 160 {
 161         assert(sec_state_is_valid(security_state));
 162         next_image_type = security_state;
 163 }
 164
 165 uint32_t bl31_get_next_image_type(void)
 166 {
 167         return next_image_type;
 168 }
 169
 170 /*******************************************************************************
 171  * This function programs EL3 registers and performs other setup to enable entry
 172  * into the next image after BL31 at the next ERET.
 173  ******************************************************************************/
 174 void __init bl31_prepare_next_image_entry(void)
 175 {
 176         entry_point_info_t *next_image_info;
 177         uint32_t image_type;
 178
 179 #if CTX_INCLUDE_AARCH32_REGS
 180         /*
 181          * Ensure that the build flag to save AArch32 system registers in CPU
 182          * context is not set for AArch64-only platforms.
 183          */
 184         if (el_implemented(1) == EL_IMPL_A64ONLY) {
 185                 ERROR("EL1 supports AArch64-only. Please set build flag "
 186                                 "CTX_INCLUDE_AARCH32_REGS = 0\n");
 187                 panic();
 188         }
 189 #endif
 190
 191         /* Determine which image to execute next */
 192         image_type = bl31_get_next_image_type();
 193
 194         /* Program EL3 registers to enable entry into the next EL */
 195         next_image_info = bl31_plat_get_next_image_ep_info(image_type);
 196         assert(next_image_info != NULL);
 197         assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
 198
 199         INFO("BL31: Preparing for EL3 exit to %s world\n",
 200                 (image_type == SECURE) ? "secure" : "normal");
 201         print_entry_point_info(next_image_info);
 202         cm_init_my_context(next_image_info);
 203         cm_prepare_el3_exit(image_type);
 204 }
 205
 206 /*******************************************************************************
 207  * This function initializes the pointer to BL32 init function. This is expected
 208  * to be called by the SPD after it finishes all its initialization
 209  ******************************************************************************/
 210 void bl31_register_bl32_init(int32_t (*func)(void))
 211 {
 212         bl32_init = func;
 213 }