File content as of revision 149:156823d33999:

/* mbed Microcontroller Library
 * Copyright (c) 2015-2016 ARM Limited
 *
 * Licensed 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.
 */
/*
 * 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];
}