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_features.h>
  12 #include <arch_helpers.h>
  13 #include <bl31/bl31.h>
  14 #include <bl31/ehf.h>
  15 #include <common/bl_common.h>
  16 #include <common/debug.h>
  17 #include <common/runtime_svc.h>
  18 #include <drivers/console.h>
  19 #include <lib/el3_runtime/context_mgmt.h>
  20 #include <lib/pmf/pmf.h>
  21 #include <lib/runtime_instr.h>
  22 #include <plat/common/platform.h>
  23 #include <services/std_svc.h>
  24
  25 #if ENABLE_RUNTIME_INSTRUMENTATION
  26 PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
  27         RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
  28 #endif
  29
  30 /*******************************************************************************
  31  * This function pointer is used to initialise the BL32 image. It's initialized
  32  * by SPD calling bl31_register_bl32_init after setting up all things necessary
  33  * for SP execution. In cases where both SPD and SP are absent, or when SPD
  34  * finds it impossible to execute SP, this pointer is left as NULL
  35  ******************************************************************************/
  36 static int32_t (*bl32_init)(void);
  37
  38 /*******************************************************************************
  39  * Variable to indicate whether next image to execute after BL31 is BL33
  40  * (non-secure & default) or BL32 (secure).
  41  ******************************************************************************/
  42 static uint32_t next_image_type = NON_SECURE;
  43
  44 /*
  45  * Implement the ARM Standard Service function to get arguments for a
  46  * particular service.
  47  */
  48 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
  49 {
  50         /* Setup the arguments for PSCI Library */
  51         DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
  52
  53         /* PSCI is the only ARM Standard Service implemented */
  54         assert(svc_mask == PSCI_FID_MASK);
  55
  56         return (uintptr_t)&psci_args;
  57 }
  58
  59 /*******************************************************************************
  60  * Simple function to initialise all BL31 helper libraries.
  61  ******************************************************************************/
  62 void __init bl31_lib_init(void)
  63 {
  64         cm_init();
  65 }
  66
  67 /*******************************************************************************
  68  * Setup function for BL31.
  69  ******************************************************************************/
  70 void bl31_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
  71                 u_register_t arg3)
  72 {
  73         /* Perform early platform-specific setup */
  74         bl31_early_platform_setup2(arg0, arg1, arg2, arg3);
  75
  76         /* Perform late platform-specific setup */
  77         bl31_plat_arch_setup();
  78
  79 #if CTX_INCLUDE_PAUTH_REGS
  80         /*
  81          * Assert that the ARMv8.3-PAuth registers are present or an access
  82          * fault will be triggered when they are being saved or restored.
  83          */
  84         assert(is_armv8_3_pauth_present());
  85 #endif /* CTX_INCLUDE_PAUTH_REGS */
  86 }
  87
  88 /*******************************************************************************
  89  * BL31 is responsible for setting up the runtime services for the primary cpu
  90  * before passing control to the bootloader or an Operating System. This
  91  * function calls runtime_svc_init() which initializes all registered runtime
  92  * services. The run time services would setup enough context for the core to
  93  * switch to the next exception level. When this function returns, the core will
  94  * switch to the programmed exception level via an ERET.
  95  ******************************************************************************/
  96 void bl31_main(void)
  97 {
  98         NOTICE("BL31: %s\n", version_string);
  99         NOTICE("BL31: %s\n", build_message);
 100
 101         /* Perform platform setup in BL31 */
 102         bl31_platform_setup();
 103
 104         /* Initialise helper libraries */
 105         bl31_lib_init();
 106
 107 #if EL3_EXCEPTION_HANDLING
 108         INFO("BL31: Initialising Exception Handling Framework\n");
 109         ehf_init();
 110 #endif
 111
 112         /* Initialize the runtime services e.g. psci. */
 113         INFO("BL31: Initializing runtime services\n");
 114         runtime_svc_init();
 115
 116         /*
 117          * All the cold boot actions on the primary cpu are done. We now need to
 118          * decide which is the next image (BL32 or BL33) and how to execute it.
 119          * If the SPD runtime service is present, it would want to pass control
 120          * to BL32 first in S-EL1. In that case, SPD would have registered a
 121          * function to initialize bl32 where it takes responsibility of entering
 122          * S-EL1 and returning control back to bl31_main. Once this is done we
 123          * can prepare entry into BL33 as normal.
 124          */
 125
 126         /*
 127          * If SPD had registered an init hook, invoke it.
 128          */
 129         if (bl32_init != NULL) {
 130                 INFO("BL31: Initializing BL32\n");
 131
 132                 int32_t rc = (*bl32_init)();
 133
 134                 if (rc == 0)
 135                         WARN("BL31: BL32 initialization failed\n");
 136         }
 137         /*
 138          * We are ready to enter the next EL. Prepare entry into the image
 139          * corresponding to the desired security state after the next ERET.
 140          */
 141         bl31_prepare_next_image_entry();
 142
 143         console_flush();
 144
 145         /*
 146          * Perform any platform specific runtime setup prior to cold boot exit
 147          * from BL31
 148          */
 149         bl31_plat_runtime_setup();
 150 }
 151
 152 /*******************************************************************************
 153  * Accessor functions to help runtime services decide which image should be
 154  * executed after BL31. This is BL33 or the non-secure bootloader image by
 155  * default but the Secure payload dispatcher could override this by requesting
 156  * an entry into BL32 (Secure payload) first. If it does so then it should use
 157  * the same API to program an entry into BL33 once BL32 initialisation is
 158  * complete.
 159  ******************************************************************************/
 160 void bl31_set_next_image_type(uint32_t security_state)
 161 {
 162         assert(sec_state_is_valid(security_state));
 163         next_image_type = security_state;
 164 }
 165
 166 uint32_t bl31_get_next_image_type(void)
 167 {
 168         return next_image_type;
 169 }
 170
 171 /*******************************************************************************
 172  * This function programs EL3 registers and performs other setup to enable entry
 173  * into the next image after BL31 at the next ERET.
 174  ******************************************************************************/
 175 void __init bl31_prepare_next_image_entry(void)
 176 {
 177         entry_point_info_t *next_image_info;
 178         uint32_t image_type;
 179
 180 #if CTX_INCLUDE_AARCH32_REGS
 181         /*
 182          * Ensure that the build flag to save AArch32 system registers in CPU
 183          * context is not set for AArch64-only platforms.
 184          */
 185         if (el_implemented(1) == EL_IMPL_A64ONLY) {
 186                 ERROR("EL1 supports AArch64-only. Please set build flag "
 187                                 "CTX_INCLUDE_AARCH32_REGS = 0\n");
 188                 panic();
 189         }
 190 #endif
 191
 192         /* Determine which image to execute next */
 193         image_type = bl31_get_next_image_type();
 194
 195         /* Program EL3 registers to enable entry into the next EL */
 196         next_image_info = bl31_plat_get_next_image_ep_info(image_type);
 197         assert(next_image_info != NULL);
 198         assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr));
 199
 200         INFO("BL31: Preparing for EL3 exit to %s world\n",
 201                 (image_type == SECURE) ? "secure" : "normal");
 202         print_entry_point_info(next_image_info);
 203         cm_init_my_context(next_image_info);
 204         cm_prepare_el3_exit(image_type);
 205 }
 206
 207 /*******************************************************************************
 208  * This function initializes the pointer to BL32 init function. This is expected
 209  * to be called by the SPD after it finishes all its initialization
 210  ******************************************************************************/
 211 void bl31_register_bl32_init(int32_t (*func)(void))
 212 {
 213         bl32_init = func;
 214 }