text: /****************************************************************************
   * arch/arm/src/stm32l4/stm32l4_mpuinit.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <assert.h>
  
  #include <nuttx/userspace.h>
  
  #include "mpu.h"
  #include "stm32l4_mpuinit.h"
  
  #if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_ARM_MPU)
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  #ifndef MAX
  #  define MAX(a,b) a > b ? a : b
  #endif
  
  #ifndef MIN
  #  define MIN(a,b) a < b ? a : b
  #endif
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: stm32l4_mpuinitialize
   *
   * Description:
   *   Configure the MPU to permit user-space access to only restricted SAM3U
   *   resources.
   *
   ****************************************************************************/
  
  void stm32l4_mpuinitialize(void)
  {
    uintptr_t datastart = MIN(USERSPACE->us_datastart, USERSPACE->us_bssstart);
    uintptr_t dataend   = MAX(USERSPACE->us_dataend,   USERSPACE->us_bssend);
  
    DEBUGASSERT(USERSPACE->us_textend >= USERSPACE->us_textstart &&
                dataend >= datastart);
  
    /* Show MPU information */
  
    mpu_showtype();
  
    /* Configure user flash and SRAM space */
  
    mpu_user_flash(USERSPACE->us_textstart,
                   USERSPACE->us_textend - USERSPACE->us_textstart);
  
    mpu_user_intsram(datastart, dataend - datastart);
  
    /* Then enable the MPU */
  
    mpu_control(true, false, true);
  }
  
  /****************************************************************************
   * Name: stm32l4_mpu_uheap
   *
   * Description:
   *  Map the user-heap region.
   *
   *  This logic may need an extension to handle external SDRAM).
   *
   ****************************************************************************/
  
  void stm32l4_mpu_uheap(uintptr_t start, size_t size)
  {
    mpu_user_intsram(start, size);
  }
  
  #endif /* CONFIG_BUILD_PROTECTED && CONFIG_ARM_MPU */
  