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LibrePilot/flight/PiOS/STM32F10x/pios_eeprom.c
2013-03-24 13:03:55 +02:00

157 lines
4.5 KiB
C

/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_EEPROM EEPROM reading/writing functions
* @brief PIOS EEPROM reading/writing functions
* @{
*
* @file pios_eeprom.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief COM layer functions
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <pios.h>
#ifdef PIOS_INCLUDE_FLASH_EEPROM
#include <stm32f10x_flash.h>
#include <pios_board_info.h>
static struct pios_eeprom_cfg config;
/**
* Initialize the flash eeprom device
* \param cfg The configuration structure.
*/
void PIOS_EEPROM_Init(const struct pios_eeprom_cfg *cfg)
{
config = *cfg;
}
/**
* Save a block of data to the flash eeprom device.
* \param data A pointer to the data to write.
* \param len The length of data to write.
* \return 0 on sucess
*/
int32_t PIOS_EEPROM_Save(uint8_t *data, uint32_t len)
{
// We need to write 32 bit words, so extend the length to be an even multiple of 4 bytes,
// and include 4 bytes for the 32 bit CRC.
uint32_t nwords = (len / 4) + 1 + (len % 4 ? 1 : 0);
uint32_t size = nwords * 4;
// Ensure that the length is not longer than the max size.
if (size > config.max_size)
return -1;
// Calculate a 32 bit CRC of the data.
uint32_t crc = PIOS_CRC32_updateCRC(0xffffffff, data, len);
// Unlock the Flash Program Erase controller
FLASH_Unlock();
// See if we have to write the data.
if ((memcmp(data, (uint8_t*)config.base_address, len) == 0) &&
(memcmp((uint8_t*)&crc, (uint8_t*)config.base_address + size - 4, 4) == 0))
return 0;
// TODO: Check that the area isn't already erased
// Erase page
FLASH_Status fs = FLASH_ErasePage(config.base_address);
if (fs != FLASH_COMPLETE)
{ // error
FLASH_Lock();
return -2;
}
// write 4 bytes at a time into program flash area (emulated EEPROM area)
uint8_t *p1 = data;
uint32_t *p3 = (uint32_t *)config.base_address;
for (int32_t i = 0; i < size; p3++)
{
uint32_t value = 0;
if (i == (size - 4))
{
// write the CRC.
value = crc;
i += 4;
}
else
{
if (i < len) value |= (uint32_t)*p1++ << 0; else value |= 0x000000ff; i++;
if (i < len) value |= (uint32_t)*p1++ << 8; else value |= 0x0000ff00; i++;
if (i < len) value |= (uint32_t)*p1++ << 16; else value |= 0x00ff0000; i++;
if (i < len) value |= (uint32_t)*p1++ << 24; else value |= 0xff000000; i++;
}
// write a 32-bit value
fs = FLASH_ProgramWord((uint32_t)p3, value);
if (fs != FLASH_COMPLETE)
{
FLASH_Lock();
return -3;
}
}
// Lock the Flash Program Erase controller
FLASH_Lock();
return 0;
}
/**
* Reads a block of data from the flash eeprom device.
* \param data A pointer to the output data buffer.
* \param len The length of data to read.
* \return 0 on sucess
*/
int32_t PIOS_EEPROM_Load(uint8_t *data, uint32_t len)
{
// We need to write 32 bit words, so the length should have been extended
// to an even multiple of 4 bytes, and should include 4 bytes for the 32 bit CRC.
uint32_t nwords = (len / 4) + 1 + (len % 4 ? 1 : 0);
uint32_t size = nwords * 4;
// Ensure that the length is not longer than the max size.
if (size > config.max_size)
return -1;
// Read the data from flash.
memcpy(data, (uint8_t*)config.base_address, len);
// Read the CRC.
uint32_t crc_flash = *((uint32_t*)(config.base_address + size - 4));
// Calculate a 32 bit CRC of the data.
uint32_t crc = PIOS_CRC32_updateCRC(0xffffffff, data, len);
if(crc != crc_flash)
return -2;
return 0;
}
#endif /* PIOS_INCLUDE_FLASH_EEPROM */