text: /*
   * Copyright (c) 2017, James Jackson and Trey Henrichsen
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * * Redistributions of source code must retain the above copyright notice, this
   *   list of conditions and the following disclaimer.
   *
   * * 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.
   *
   * * 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.
   */
  
  #include "string.h"
  #include "system.h"
  
  #include "eeprom.h"
  
  void eeprom_init()
  {
    return;//nothing needed
  }
  //Reads the data stored in flash sector 11
  bool eeprom_read(void * dest, uint8_t len)
  {
    memcpy(dest, FLASH_SECTOR11_START, len);
    return true;
  }
  //writes to the 11th sector, which is used for persistant storage
  bool eeprom_write(const void* src, uint8_t len)
  {
    return flash_write(FLASH_SECTOR11_START, src,len);
  }
  //Reads from the specified location. Note that there is no error checking
  bool flash_read(void* flash_loc,void* dest, uint8_t len)
  {
    memcpy(dest, flash_loc, len);
    return true;
  }
  //Erases the 11th sector, which is used for persistent storage
  bool flash_erase()
  {
    FLASH_Unlock();
    FLASH_EraseSector(FLASH_Sector_11,VoltageRange_3);
    return true;
  }
  //writes data to the given location. Note that there is no error checking
  bool flash_write(void const* flash_loc, void const* data, uint8_t len)
  {
    flash_erase();
    FLASH->CR|=FLASH_CR_PG;
    uint32_t const* dataPtr = static_cast<uint32_t const*>(data);
    uint32_t flash_address= reinterpret_cast<const uint32_t>(flash_loc);
    for (uint32_t i=0;i<len;i+=4)
      FLASH_ProgramWord(flash_address+i,*(dataPtr++));
    return true;
  }
  