begriffs open source - freertos/blob - portable/GCC/ARM_CM33/secure/secure_context_port.c

   1 /*\r
   2  * FreeRTOS Kernel <DEVELOPMENT BRANCH>\r
   3  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.\r
   4  *\r
   5  * SPDX-License-Identifier: MIT
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy of\r
   8  * this software and associated documentation files (the "Software"), to deal in\r
   9  * the Software without restriction, including without limitation the rights to\r
  10  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of\r
  11  * the Software, and to permit persons to whom the Software is furnished to do so,\r
  12  * subject to the following conditions:\r
  13  *\r
  14  * The above copyright notice and this permission notice shall be included in all\r
  15  * copies or substantial portions of the Software.\r
  16  *\r
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
  19  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
  20  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
  21  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  23  *\r
  24  * https://www.FreeRTOS.org\r
  25  * https://github.com/FreeRTOS\r
  26  *\r
  27  */\r
  28 \r
  29 /* Secure context includes. */\r
  30 #include "secure_context.h"\r
  31 \r
  32 /* Secure port macros. */\r
  33 #include "secure_port_macros.h"\r
  34 \r
  35 secureportNON_SECURE_CALLABLE void SecureContext_LoadContext( SecureContextHandle_t xSecureContextHandle )\r
  36 {\r
  37     /* xSecureContextHandle value is in r0. */\r
  38     __asm volatile\r
  39     (\r
  40         "       .syntax unified                                                 \n"\r
  41         "                                                                                       \n"\r
  42         "       mrs r1, ipsr                                                    \n"/* r1 = IPSR. */\r
  43         "       cbz r1, load_ctx_therad_mode                    \n"/* Do nothing if the processor is running in the Thread Mode. */\r
  44         "       ldmia r0!, {r1, r2}                                             \n"/* r1 = xSecureContextHandle->pucCurrentStackPointer, r2 = xSecureContextHandle->pucStackLimit. */\r
  45         #if ( configENABLE_MPU == 1 )\r
  46             "   ldmia r1!, {r3}                                                 \n"/* Read CONTROL register value from task's stack. r3 = CONTROL. */\r
  47             "   msr control, r3                                                 \n"/* CONTROL = r3. */\r
  48         #endif /* configENABLE_MPU */\r
  49         "       msr psplim, r2                                                  \n"/* PSPLIM = r2. */\r
  50         "       msr psp, r1                                                             \n"/* PSP = r1. */\r
  51         "                                                                                       \n"\r
  52         " load_ctx_therad_mode:                                         \n"\r
  53         "       nop                                                                             \n"\r
  54         "                                                                                       \n"\r
  55         ::: "r0", "r1", "r2"\r
  56     );\r
  57 }\r
  58 /*-----------------------------------------------------------*/\r
  59 \r
  60 secureportNON_SECURE_CALLABLE void SecureContext_SaveContext( SecureContextHandle_t xSecureContextHandle )\r
  61 {\r
  62     /* xSecureContextHandle value is in r0. */\r
  63     __asm volatile\r
  64     (\r
  65         "       .syntax unified                                                 \n"\r
  66         "                                                                                       \n"\r
  67         "       mrs r1, ipsr                                                    \n"/* r1 = IPSR. */\r
  68         "       cbz r1, save_ctx_therad_mode                    \n"/* Do nothing if the processor is running in the Thread Mode. */\r
  69         "       mrs r1, psp                                                             \n"/* r1 = PSP. */\r
  70         #if ( configENABLE_FPU == 1 )\r
  71             "   vstmdb r1!, {s0}                                                \n"/* Trigger the defferred stacking of FPU registers. */\r
  72             "   vldmia r1!, {s0}                                                \n"/* Nullify the effect of the pervious statement. */\r
  73         #endif /* configENABLE_FPU */\r
  74         #if ( configENABLE_MPU == 1 )\r
  75             "   mrs r2, control                                                 \n"/* r2 = CONTROL. */\r
  76             "   stmdb r1!, {r2}                                                 \n"/* Store CONTROL value on the stack. */\r
  77         #endif /* configENABLE_MPU */\r
  78         "       str r1, [r0]                                                    \n"/* Save the top of stack in context. xSecureContextHandle->pucCurrentStackPointer = r1. */\r
  79         "       movs r1, %0                                                             \n"/* r1 = securecontextNO_STACK. */\r
  80         "       msr psplim, r1                                                  \n"/* PSPLIM = securecontextNO_STACK. */\r
  81         "       msr psp, r1                                                             \n"/* PSP = securecontextNO_STACK i.e. No stack for thread mode until next task's context is loaded. */\r
  82         "                                                                                       \n"\r
  83         " save_ctx_therad_mode:                                         \n"\r
  84         "       nop                                                                             \n"\r
  85         "                                                                                       \n"\r
  86         ::"i" ( securecontextNO_STACK ) : "r1", "memory"\r
  87     );\r
  88 }\r
  89 /*-----------------------------------------------------------*/\r