text: /* mbed Microcontroller Library
   * CMSIS-style functionality to support dynamic vectors
   *******************************************************************************
   * Copyright (c) 2014, STMicroelectronics
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   * 3. Neither the name of STMicroelectronics nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *******************************************************************************
   */ 
  #include "cmsis_nvic.h"
  
  #define NVIC_RAM_VECTOR_ADDRESS   (0x20000000)  // Vectors positioned at start of RAM
  #define NVIC_FLASH_VECTOR_ADDRESS (0x08000000)  // Initial vector position in flash
  
  static unsigned char vtor_remap = 0; // To keep track that the vectors remap is done
  
  void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector) {
      int i;
      // Space for dynamic vectors, initialised to allocate in R/W
      static volatile uint32_t *vectors = (uint32_t *)NVIC_RAM_VECTOR_ADDRESS;
      
      // Copy and switch to dynamic vectors if first time called
      if (vtor_remap == 0) {
        uint32_t *old_vectors = (uint32_t *)NVIC_FLASH_VECTOR_ADDRESS;
        for (i = 0; i < NVIC_NUM_VECTORS; i++) {
            vectors[i] = old_vectors[i];
        }
        SYSCFG->CFGR1 |= 0x03; // Embedded SRAM mapped at 0x00000000
        vtor_remap = 1; // The vectors remap is done
      }
  
      // Set the vector
      vectors[IRQn + 16] = vector;
  }
  
  uint32_t NVIC_GetVector(IRQn_Type IRQn) {
      uint32_t *vectors = (uint32_t*)NVIC_RAM_VECTOR_ADDRESS;
      // Return the vector
      return vectors[IRQn + 16];
  }
  