bl1/aarch64/bl1_context_mgmt.c

   1 /*
   2  * Copyright (c) 2015-2017, 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_helpers.h>
  32 #include <assert.h>
  33 #include <context.h>
  34 #include <context_mgmt.h>
  35 #include <debug.h>
  36 #include <platform.h>
  37
  38 /*
  39  * Following array will be used for context management.
  40  * There are 2 instances, for the Secure and Non-Secure contexts.
  41  */
  42 static cpu_context_t bl1_cpu_context[2];
  43
  44 /* Following contains the cpu context pointers. */
  45 static void *bl1_cpu_context_ptr[2];
  46
  47
  48 void *cm_get_context(uint32_t security_state)
  49 {
  50         assert(sec_state_is_valid(security_state));
  51         return bl1_cpu_context_ptr[security_state];
  52 }
  53
  54 void cm_set_context(void *context, uint32_t security_state)
  55 {
  56         assert(sec_state_is_valid(security_state));
  57         bl1_cpu_context_ptr[security_state] = context;
  58 }
  59
  60 /*******************************************************************************
  61  * This function prepares the context for Secure/Normal world images.
  62  * Normal world images are transitioned to EL2(if supported) else EL1.
  63  ******************************************************************************/
  64 void bl1_prepare_next_image(unsigned int image_id)
  65 {
  66         unsigned int security_state;
  67         image_desc_t *image_desc;
  68         entry_point_info_t *next_bl_ep;
  69
  70 #if CTX_INCLUDE_AARCH32_REGS
  71         /*
  72          * Ensure that the build flag to save AArch32 system registers in CPU
  73          * context is not set for AArch64-only platforms.
  74          */
  75         if (EL_IMPLEMENTED(1) == EL_IMPL_A64ONLY) {
  76                 ERROR("EL1 supports AArch64-only. Please set build flag "
  77                                 "CTX_INCLUDE_AARCH32_REGS = 0");
  78                 panic();
  79         }
  80 #endif
  81
  82         /* Get the image descriptor. */
  83         image_desc = bl1_plat_get_image_desc(image_id);
  84         assert(image_desc);
  85
  86         /* Get the entry point info. */
  87         next_bl_ep = &image_desc->ep_info;
  88
  89         /* Get the image security state. */
  90         security_state = GET_SECURITY_STATE(next_bl_ep->h.attr);
  91
  92         /* Setup the Secure/Non-Secure context if not done already. */
  93         if (!cm_get_context(security_state))
  94                 cm_set_context(&bl1_cpu_context[security_state], security_state);
  95
  96         /* Prepare the SPSR for the next BL image. */
  97         if (security_state == SECURE) {
  98                 next_bl_ep->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
  99                                    DISABLE_ALL_EXCEPTIONS);
 100         } else {
 101                 /* Use EL2 if supported; else use EL1. */
 102                 if (EL_IMPLEMENTED(2)) {
 103                         next_bl_ep->spsr = SPSR_64(MODE_EL2, MODE_SP_ELX,
 104                                 DISABLE_ALL_EXCEPTIONS);
 105                 } else {
 106                         next_bl_ep->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
 107                            DISABLE_ALL_EXCEPTIONS);
 108                 }
 109         }
 110
 111         /* Allow platform to make change */
 112         bl1_plat_set_ep_info(image_id, next_bl_ep);
 113
 114         /* Prepare the context for the next BL image. */
 115         cm_init_my_context(next_bl_ep);
 116         cm_prepare_el3_exit(security_state);
 117
 118         /* Indicate that image is in execution state. */
 119         image_desc->state = IMAGE_STATE_EXECUTED;
 120
 121         print_entry_point_info(next_bl_ep);
 122 }