bl1/aarch64/bl1_context_mgmt.c

   1 /*
   2  * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  */
   6
   7 #include <arch_helpers.h>
   8 #include <assert.h>
   9 #include <context.h>
  10 #include <context_mgmt.h>
  11 #include <debug.h>
  12 #include <platform.h>
  13 #include "../bl1_private.h"
  14
  15 /*
  16  * Following array will be used for context management.
  17  * There are 2 instances, for the Secure and Non-Secure contexts.
  18  */
  19 static cpu_context_t bl1_cpu_context[2];
  20
  21 /* Following contains the cpu context pointers. */
  22 static void *bl1_cpu_context_ptr[2];
  23
  24
  25 void *cm_get_context(uint32_t security_state)
  26 {
  27         assert(sec_state_is_valid(security_state));
  28         return bl1_cpu_context_ptr[security_state];
  29 }
  30
  31 void cm_set_context(void *context, uint32_t security_state)
  32 {
  33         assert(sec_state_is_valid(security_state));
  34         bl1_cpu_context_ptr[security_state] = context;
  35 }
  36
  37 /*******************************************************************************
  38  * This function prepares the context for Secure/Normal world images.
  39  * Normal world images are transitioned to EL2(if supported) else EL1.
  40  ******************************************************************************/
  41 void bl1_prepare_next_image(unsigned int image_id)
  42 {
  43         unsigned int security_state;
  44         image_desc_t *image_desc;
  45         entry_point_info_t *next_bl_ep;
  46
  47 #if CTX_INCLUDE_AARCH32_REGS
  48         /*
  49          * Ensure that the build flag to save AArch32 system registers in CPU
  50          * context is not set for AArch64-only platforms.
  51          */
  52         if (el_implemented(1) == EL_IMPL_A64ONLY) {
  53                 ERROR("EL1 supports AArch64-only. Please set build flag "
  54                                 "CTX_INCLUDE_AARCH32_REGS = 0\n");
  55                 panic();
  56         }
  57 #endif
  58
  59         /* Get the image descriptor. */
  60         image_desc = bl1_plat_get_image_desc(image_id);
  61         assert(image_desc);
  62
  63         /* Get the entry point info. */
  64         next_bl_ep = &image_desc->ep_info;
  65
  66         /* Get the image security state. */
  67         security_state = GET_SECURITY_STATE(next_bl_ep->h.attr);
  68
  69         /* Setup the Secure/Non-Secure context if not done already. */
  70         if (!cm_get_context(security_state))
  71                 cm_set_context(&bl1_cpu_context[security_state], security_state);
  72
  73         /* Prepare the SPSR for the next BL image. */
  74         if (security_state == SECURE) {
  75                 next_bl_ep->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
  76                                    DISABLE_ALL_EXCEPTIONS);
  77         } else {
  78                 /* Use EL2 if supported; else use EL1. */
  79                 if (el_implemented(2) != EL_IMPL_NONE) {
  80                         next_bl_ep->spsr = SPSR_64(MODE_EL2, MODE_SP_ELX,
  81                                 DISABLE_ALL_EXCEPTIONS);
  82                 } else {
  83                         next_bl_ep->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
  84                            DISABLE_ALL_EXCEPTIONS);
  85                 }
  86         }
  87
  88         /* Allow platform to make change */
  89         bl1_plat_set_ep_info(image_id, next_bl_ep);
  90
  91         /* Prepare the context for the next BL image. */
  92         cm_init_my_context(next_bl_ep);
  93         cm_prepare_el3_exit(security_state);
  94
  95         /* Indicate that image is in execution state. */
  96         image_desc->state = IMAGE_STATE_EXECUTED;
  97
  98         print_entry_point_info(next_bl_ep);
  99 }