File content as of revision 580:3c14cb9b87c5:

/* MPS2 CMSIS Library
*
* Copyright (c) 2006-2015 ARM Limited
* 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 the copyright holder 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. 
*******************************************************************************
* CMSIS-style functionality to support dynamic vectors
*******************************************************************************/
#include "cmsis_nvic.h"

#define NVIC_RAM_VECTOR_ADDRESS   (0x20000000)  // Location of vectors in RAM
#define NVIC_FLASH_VECTOR_ADDRESS (0x00000000)  // Initial vector position in flash

void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector) {
    uint32_t *vectors = (uint32_t*)SCB->VTOR;
    uint32_t i;

    // Copy and switch to dynamic vectors if the first time called
    if (SCB->VTOR == NVIC_FLASH_VECTOR_ADDRESS) {
        uint32_t *old_vectors = vectors;
        vectors = (uint32_t*)NVIC_RAM_VECTOR_ADDRESS;
        for (i=0; i<NVIC_NUM_VECTORS; i++) {
            vectors[i] = old_vectors[i];
        }
        SCB->VTOR = (uint32_t)NVIC_RAM_VECTOR_ADDRESS;
    }
    vectors[IRQn + NVIC_USER_IRQ_OFFSET] = vector;
}

uint32_t NVIC_GetVector(IRQn_Type IRQn) {
    uint32_t *vectors = (uint32_t*)SCB->VTOR;
    return vectors[IRQn + NVIC_USER_IRQ_OFFSET];
}