text: /**
   ******************************************************************************
   * @file    EEPROM_Emulation/src/eeprom.c
   * @author  MCD Application Team
   * @version V1.0.0
   * @date    10-October-2011
   * @brief   This file provides all the EEPROM emulation firmware functions.
   ******************************************************************************
   * @attention
   *
   * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
   * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
   * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
   * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
   * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
   * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
   *
   * <h2><center>&copy; COPYRIGHT 2011 STMicroelectronics</center></h2>
   ******************************************************************************
   */
  
  /** @addtogroup EEPROM_Emulation
   * @{
   */
  
  /* Includes ------------------------------------------------------------------*/
  #include "eeprom.h"
  #include "stm32f4xx_conf.h"
  //#include "flash_helper.h"
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  
  /* Global variable used to store variable value in read sequence */
  uint16_t DataVar = 0;
  
  /* Virtual address defined by the user: 0xFFFF value is prohibited */
  extern uint16_t VirtAddVarTab[NB_OF_VAR];
  
  /* Private function prototypes -----------------------------------------------*/
  /* Private functions ---------------------------------------------------------*/
  static FLASH_Status EE_Format(void);
  static uint16_t EE_FindValidPage(uint8_t Operation);
  static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint16_t Data);
  static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint16_t Data);
  static uint16_t EE_EraseSectorIfNotEmpty(uint32_t FLASH_Sector, uint8_t VoltageRange);
  
  /**
   * @brief  Restore the pages to a known good state in case of page's status
   *   corruption after a power loss.
   * @param  None.
   * @retval - Flash error code: on write Flash error
   *         - FLASH_COMPLETE: on success
   */
  uint16_t EE_Init(void)
  {
  	uint16_t PageStatus0 = 6, PageStatus1 = 6;
  	uint16_t VarIdx = 0;
  	uint16_t EepromStatus = 0, ReadStatus = 0;
  	int16_t x = -1;
  	uint16_t  FlashStatus;
  
  	/* Get Page0 status */
  	PageStatus0 = (*(__IO uint16_t*)PAGE0_BASE_ADDRESS);
  	/* Get Page1 status */
  	PageStatus1 = (*(__IO uint16_t*)PAGE1_BASE_ADDRESS);
  
  	/* Check for invalid header states and repair if necessary */
  	switch (PageStatus0)
  	{
  	case ERASED:
  		if (PageStatus1 == VALID_PAGE) /* Page0 erased, Page1 valid */
  		{
  			/* Erase Page0 */
  			FlashStatus = EE_EraseSectorIfNotEmpty(PAGE0_ID,VOLTAGE_RANGE);
  			/* If erase operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		else if (PageStatus1 == RECEIVE_DATA) /* Page0 erased, Page1 receive */
  		{
  			/* Erase Page0 */
  			FlashStatus = EE_EraseSectorIfNotEmpty(PAGE0_ID, VOLTAGE_RANGE);
  			/* If erase operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  			/* Mark Page1 as valid */
  			FlashStatus = FLASH_ProgramHalfWord(PAGE1_BASE_ADDRESS, VALID_PAGE);
  			/* If program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		else /* First EEPROM access (Page0&1 are erased) or invalid state -> format EEPROM */
  		{
  			/* Erase both Page0 and Page1 and set Page0 as valid page */
  			FlashStatus = EE_Format();
  			/* If erase/program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		break;
  
  	case RECEIVE_DATA:
  		if (PageStatus1 == VALID_PAGE) /* Page0 receive, Page1 valid */
  		{
  			/* Transfer data from Page1 to Page0 */
  			for (VarIdx = 0; VarIdx < NB_OF_VAR; VarIdx++)
  			{
  				if (( *(__IO uint16_t*)(PAGE0_BASE_ADDRESS + 6)) == VirtAddVarTab[VarIdx])
  				{
  					x = VarIdx;
  				}
  				if (VarIdx != x)
  				{
  					/* Read the last variables' updates */
  					ReadStatus = EE_ReadVariable(VirtAddVarTab[VarIdx], &DataVar);
  					/* In case variable corresponding to the virtual address was found */
  					if (ReadStatus != 0x1)
  					{
  						/* Transfer the variable to the Page0 */
  						EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddVarTab[VarIdx], DataVar);
  						/* If program operation was failed, a Flash error code is returned */
  						if (EepromStatus != FLASH_COMPLETE)
  						{
  							return EepromStatus;
  						}
  					}
  				}
  			}
  			/* Mark Page0 as valid */
  			FlashStatus = FLASH_ProgramHalfWord(PAGE0_BASE_ADDRESS, VALID_PAGE);
  			/* If program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  			/* Erase Page1 */
  			FlashStatus = EE_EraseSectorIfNotEmpty(PAGE1_ID, VOLTAGE_RANGE);
  			/* If erase operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		else if (PageStatus1 == ERASED) /* Page0 receive, Page1 erased */
  		{
  			/* Erase Page1 */
  			FlashStatus = EE_EraseSectorIfNotEmpty(PAGE1_ID, VOLTAGE_RANGE);
  			/* If erase operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  			/* Mark Page0 as valid */
  			FlashStatus = FLASH_ProgramHalfWord(PAGE0_BASE_ADDRESS, VALID_PAGE);
  			/* If program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		else /* Invalid state -> format eeprom */
  		{
  			/* Erase both Page0 and Page1 and set Page0 as valid page */
  			FlashStatus = EE_Format();
  			/* If erase/program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		break;
  
  	case VALID_PAGE:
  		if (PageStatus1 == VALID_PAGE) /* Invalid state -> format eeprom */
  		{
  			/* Erase both Page0 and Page1 and set Page0 as valid page */
  			FlashStatus = EE_Format();
  			/* If erase/program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		else if (PageStatus1 == ERASED) /* Page0 valid, Page1 erased */
  		{
  			/* Erase Page1 */
  			FlashStatus = EE_EraseSectorIfNotEmpty(PAGE1_ID, VOLTAGE_RANGE);
  			/* If erase operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		else /* Page0 valid, Page1 receive */
  		{
  			/* Transfer data from Page0 to Page1 */
  			for (VarIdx = 0; VarIdx < NB_OF_VAR; VarIdx++)
  			{
  				if ((*(__IO uint16_t*)(PAGE1_BASE_ADDRESS + 6)) == VirtAddVarTab[VarIdx])
  				{
  					x = VarIdx;
  				}
  				if (VarIdx != x)
  				{
  					/* Read the last variables' updates */
  					ReadStatus = EE_ReadVariable(VirtAddVarTab[VarIdx], &DataVar);
  					/* In case variable corresponding to the virtual address was found */
  					if (ReadStatus != 0x1)
  					{
  						/* Transfer the variable to the Page1 */
  						EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddVarTab[VarIdx], DataVar);
  						/* If program operation was failed, a Flash error code is returned */
  						if (EepromStatus != FLASH_COMPLETE)
  						{
  							return EepromStatus;
  						}
  					}
  				}
  			}
  			/* Mark Page1 as valid */
  			FlashStatus = FLASH_ProgramHalfWord(PAGE1_BASE_ADDRESS, VALID_PAGE);
  			/* If program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  			/* Erase Page0 */
  			FlashStatus = EE_EraseSectorIfNotEmpty(PAGE0_ID, VOLTAGE_RANGE);
  			/* If erase operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  		}
  		break;
  
  	default:  /* Any other state -> format eeprom */
  		/* Erase both Page0 and Page1 and set Page0 as valid page */
  		FlashStatus = EE_Format();
  		/* If erase/program operation was failed, a Flash error code is returned */
  		if (FlashStatus != FLASH_COMPLETE)
  		{
  			return FlashStatus;
  		}
  		break;
  	}
  
  	return FLASH_COMPLETE;
  }
  
  /**
   * @brief  Returns the last stored variable data, if found, which correspond to
   *   the passed virtual address
   * @param  VirtAddress: Variable virtual address
   * @param  Data: Global variable contains the read variable value
   * @retval Success or error status:
   *           - 0: if variable was found
   *           - 1: if the variable was not found
   *           - NO_VALID_PAGE: if no valid page was found.
   */
  uint16_t EE_ReadVariable(uint16_t VirtAddress, uint16_t* Data)
  {
  	uint16_t ValidPage = PAGE0;
  	uint16_t AddressValue = 0x5555, ReadStatus = 1;
  	uint32_t Address = EEPROM_START_ADDRESS, PageStartAddress = EEPROM_START_ADDRESS;
  
  	/* Get active Page for read operation */
  	ValidPage = EE_FindValidPage(READ_FROM_VALID_PAGE);
  
  	/* Check if there is no valid page */
  	if (ValidPage == NO_VALID_PAGE)
  	{
  		return  NO_VALID_PAGE;
  	}
  
  	/* Get the valid Page start Address */
  	PageStartAddress = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(ValidPage * PAGE_SIZE));
  
  	/* Get the valid Page end Address */
  	Address = (uint32_t)((EEPROM_START_ADDRESS - 2) + (uint32_t)((1 + ValidPage) * PAGE_SIZE));
  
  	/* Check each active page address starting from end */
  	while (Address > (PageStartAddress + 2))
  	{
  		/* Get the current location content to be compared with virtual address */
  		AddressValue = (*(__IO uint16_t*)Address);
  
  		/* Compare the read address with the virtual address */
  		if (AddressValue == VirtAddress)
  		{
  			/* Get content of Address-2 which is variable value */
  			*Data = (*(__IO uint16_t*)(Address - 2));
  
  			/* In case variable value is read, reset ReadStatus flag */
  			ReadStatus = 0;
  
  			break;
  		}
  		else
  		{
  			/* Next address location */
  			Address = Address - 4;
  		}
  	}
  
  	/* Return ReadStatus value: (0: variable exist, 1: variable doesn't exist) */
  	return ReadStatus;
  }
  
  /**
   * @brief  Writes/upadtes variable data in EEPROM.
   * @param  VirtAddress: Variable virtual address
   * @param  Data: 16 bit data to be written
   * @retval Success or error status:
   *           - FLASH_COMPLETE: on success
   *           - PAGE_FULL: if valid page is full
   *           - NO_VALID_PAGE: if no valid page was found
   *           - Flash error code: on write Flash error
   */
  uint16_t EE_WriteVariable(uint16_t VirtAddress, uint16_t Data)
  {
  	uint16_t Status = 0;
  
  	/* Write the variable virtual address and value in the EEPROM */
  	Status = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
  
  	/* In case the EEPROM active page is full */
  	if (Status == PAGE_FULL)
  	{
  		/* Perform Page transfer */
  		Status = EE_PageTransfer(VirtAddress, Data);
  	}
  
  	/* Return last operation status */
  	return Status;
  }
  
  /**
   * @brief  Erases PAGE and PAGE1 and writes VALID_PAGE header to PAGE
   * @param  None
   * @retval Status of the last operation (Flash write or erase) done during
   *         EEPROM formating
   */
  static FLASH_Status EE_Format(void)
  {
  	FLASH_Status FlashStatus = FLASH_COMPLETE;
  
  	/* Erase Page0 */
  	FlashStatus = EE_EraseSectorIfNotEmpty(PAGE0_ID, VOLTAGE_RANGE);
  
  	/* If erase operation was failed, a Flash error code is returned */
  	if (FlashStatus != FLASH_COMPLETE)
  	{
  		return FlashStatus;
  	}
  
  	/* Set Page0 as valid page: Write VALID_PAGE at Page0 base address */
  	FlashStatus = FLASH_ProgramHalfWord(PAGE0_BASE_ADDRESS, VALID_PAGE);
  
  	/* If program operation was failed, a Flash error code is returned */
  	if (FlashStatus != FLASH_COMPLETE)
  	{
  		return FlashStatus;
  	}
  
  	/* Erase Page1 */
  	FlashStatus = EE_EraseSectorIfNotEmpty(PAGE1_ID, VOLTAGE_RANGE);
  
  	/* Return Page1 erase operation status */
  	return FlashStatus;
  }
  
  /**
   * @brief  Find valid Page for write or read operation
   * @param  Operation: operation to achieve on the valid page.
   *   This parameter can be one of the following values:
   *     @arg READ_FROM_VALID_PAGE: read operation from valid page
   *     @arg WRITE_IN_VALID_PAGE: write operation from valid page
   * @retval Valid page number (PAGE or PAGE1) or NO_VALID_PAGE in case
   *   of no valid page was found
   */
  static uint16_t EE_FindValidPage(uint8_t Operation)
  {
  	uint16_t PageStatus0 = 6, PageStatus1 = 6;
  
  	/* Get Page0 actual status */
  	PageStatus0 = (*(__IO uint16_t*)PAGE0_BASE_ADDRESS);
  
  	/* Get Page1 actual status */
  	PageStatus1 = (*(__IO uint16_t*)PAGE1_BASE_ADDRESS);
  
  	/* Write or read operation */
  	switch (Operation)
  	{
  	case WRITE_IN_VALID_PAGE:   /* ---- Write operation ---- */
  		if (PageStatus1 == VALID_PAGE)
  		{
  			/* Page0 receiving data */
  			if (PageStatus0 == RECEIVE_DATA)
  			{
  				return PAGE0;         /* Page0 valid */
  			}
  			else
  			{
  				return PAGE1;         /* Page1 valid */
  			}
  		}
  		else if (PageStatus0 == VALID_PAGE)
  		{
  			/* Page1 receiving data */
  			if (PageStatus1 == RECEIVE_DATA)
  			{
  				return PAGE1;         /* Page1 valid */
  			}
  			else
  			{
  				return PAGE0;         /* Page0 valid */
  			}
  		}
  		else
  		{
  			return NO_VALID_PAGE;   /* No valid Page */
  		}
  
  	case READ_FROM_VALID_PAGE:  /* ---- Read operation ---- */
  		if (PageStatus0 == VALID_PAGE)
  		{
  			return PAGE0;           /* Page0 valid */
  		}
  		else if (PageStatus1 == VALID_PAGE)
  		{
  			return PAGE1;           /* Page1 valid */
  		}
  		else
  		{
  			return NO_VALID_PAGE ;  /* No valid Page */
  		}
  
  	default:
  		return PAGE0;             /* Page0 valid */
  	}
  }
  
  /**
   * @brief  Verify if active page is full and Writes variable in EEPROM.
   * @param  VirtAddress: 16 bit virtual address of the variable
   * @param  Data: 16 bit data to be written as variable value
   * @retval Success or error status:
   *           - FLASH_COMPLETE: on success
   *           - PAGE_FULL: if valid page is full
   *           - NO_VALID_PAGE: if no valid page was found
   *           - Flash error code: on write Flash error
   */
  static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint16_t Data)
  {
  	FLASH_Status FlashStatus = FLASH_COMPLETE;
  	uint16_t ValidPage = PAGE0;
  	uint32_t Address = EEPROM_START_ADDRESS, PageEndAddress = EEPROM_START_ADDRESS+PAGE_SIZE;
  
  	/* Get valid Page for write operation */
  	ValidPage = EE_FindValidPage(WRITE_IN_VALID_PAGE);
  
  	/* Check if there is no valid page */
  	if (ValidPage == NO_VALID_PAGE)
  	{
  		return  NO_VALID_PAGE;
  	}
  
  	/* Get the valid Page start Address */
  	Address = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(ValidPage * PAGE_SIZE));
  
  	/* Get the valid Page end Address */
  	PageEndAddress = (uint32_t)((EEPROM_START_ADDRESS - 2) + (uint32_t)((1 + ValidPage) * PAGE_SIZE));
  
  	/* Check each active page address starting from begining */
  	while (Address < PageEndAddress)
  	{
  		/* Verify if Address and Address+2 contents are 0xFFFFFFFF */
  		if ((*(__IO uint32_t*)Address) == 0xFFFFFFFF)
  		{
  			/* Set variable data */
  			FlashStatus = FLASH_ProgramHalfWord(Address, Data);
  			/* If program operation was failed, a Flash error code is returned */
  			if (FlashStatus != FLASH_COMPLETE)
  			{
  				return FlashStatus;
  			}
  			/* Set variable virtual address */
  			FlashStatus = FLASH_ProgramHalfWord(Address + 2, VirtAddress);
  			/* Return program operation status */
  			return FlashStatus;
  		}
  		else
  		{
  			/* Next address location */
  			Address = Address + 4;
  		}
  	}
  
  	/* Return PAGE_FULL in case the valid page is full */
  	return PAGE_FULL;
  }
  
  /**
   * @brief  Transfers last updated variables data from the full Page to
   *   an empty one.
   * @param  VirtAddress: 16 bit virtual address of the variable
   * @param  Data: 16 bit data to be written as variable value
   * @retval Success or error status:
   *           - FLASH_COMPLETE: on success
   *           - PAGE_FULL: if valid page is full
   *           - NO_VALID_PAGE: if no valid page was found
   *           - Flash error code: on write Flash error
   */
  static uint16_t EE_PageTransfer(uint16_t VirtAddress, uint16_t Data)
  {
  	FLASH_Status FlashStatus = FLASH_COMPLETE;
  	uint32_t NewPageAddress = EEPROM_START_ADDRESS;
  	uint16_t OldPageId=0;
  	uint16_t ValidPage = PAGE0, VarIdx = 0;
  	uint16_t EepromStatus = 0, ReadStatus = 0;
  
  	/* Get active Page for read operation */
  	ValidPage = EE_FindValidPage(READ_FROM_VALID_PAGE);
  
  	if (ValidPage == PAGE1)       /* Page1 valid */
  	{
  		/* New page address where variable will be moved to */
  		NewPageAddress = PAGE0_BASE_ADDRESS;
  
  		/* Old page ID where variable will be taken from */
  		OldPageId = PAGE1_ID;
  	}
  	else if (ValidPage == PAGE0)  /* Page0 valid */
  	{
  		/* New page address  where variable will be moved to */
  		NewPageAddress = PAGE1_BASE_ADDRESS;
  
  		/* Old page ID where variable will be taken from */
  		OldPageId = PAGE0_ID;
  	}
  	else
  	{
  		return NO_VALID_PAGE;       /* No valid Page */
  	}
  
  	/* Set the new Page status to RECEIVE_DATA status */
  	FlashStatus = FLASH_ProgramHalfWord(NewPageAddress, RECEIVE_DATA);
  	/* If program operation was failed, a Flash error code is returned */
  	if (FlashStatus != FLASH_COMPLETE)
  	{
  		return FlashStatus;
  	}
  
  	/* Write the variable passed as parameter in the new active page */
  	EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
  	/* If program operation was failed, a Flash error code is returned */
  	if (EepromStatus != FLASH_COMPLETE)
  	{
  		return EepromStatus;
  	}
  
  	/* Transfer process: transfer variables from old to the new active page */
  	for (VarIdx = 0; VarIdx < NB_OF_VAR; VarIdx++)
  	{
  		if (VirtAddVarTab[VarIdx] != VirtAddress)  /* Check each variable except the one passed as parameter */
  		{
  			/* Read the other last variable updates */
  			ReadStatus = EE_ReadVariable(VirtAddVarTab[VarIdx], &DataVar);
  			/* In case variable corresponding to the virtual address was found */
  			if (ReadStatus != 0x1)
  			{
  				/* Transfer the variable to the new active page */
  				EepromStatus = EE_VerifyPageFullWriteVariable(VirtAddVarTab[VarIdx], DataVar);
  				/* If program operation was failed, a Flash error code is returned */
  				if (EepromStatus != FLASH_COMPLETE)
  				{
  					return EepromStatus;
  				}
  			}
  		}
  	}
  
  	/* Erase the old Page: Set old Page status to ERASED status */
  	FlashStatus = EE_EraseSectorIfNotEmpty(OldPageId, VOLTAGE_RANGE);
  	/* If erase operation was failed, a Flash error code is returned */
  	if (FlashStatus != FLASH_COMPLETE)
  	{
  		return FlashStatus;
  	}
  
  	/* Set new Page status to VALID_PAGE status */
  	FlashStatus = FLASH_ProgramHalfWord(NewPageAddress, VALID_PAGE);
  	/* If program operation was failed, a Flash error code is returned */
  	if (FlashStatus != FLASH_COMPLETE)
  	{
  		return FlashStatus;
  	}
  
  	/* Return last operation flash status */
  	return FlashStatus;
  }
  
  // Copied from VESC/flash_helper.cc
  
  #define FLASH_SECTORS                   12
  
  // Base address of the Flash sectors
  #define ADDR_FLASH_SECTOR_0     ((uint32_t)0x08000000) // Base @ of Sector 0, 16 Kbytes
  #define ADDR_FLASH_SECTOR_1     ((uint32_t)0x08004000) // Base @ of Sector 1, 16 Kbytes
  #define ADDR_FLASH_SECTOR_2     ((uint32_t)0x08008000) // Base @ of Sector 2, 16 Kbytes
  #define ADDR_FLASH_SECTOR_3     ((uint32_t)0x0800C000) // Base @ of Sector 3, 16 Kbytes
  #define ADDR_FLASH_SECTOR_4     ((uint32_t)0x08010000) // Base @ of Sector 4, 64 Kbytes
  #define ADDR_FLASH_SECTOR_5     ((uint32_t)0x08020000) // Base @ of Sector 5, 128 Kbytes
  #define ADDR_FLASH_SECTOR_6     ((uint32_t)0x08040000) // Base @ of Sector 6, 128 Kbytes
  #define ADDR_FLASH_SECTOR_7     ((uint32_t)0x08060000) // Base @ of Sector 7, 128 Kbytes
  #define ADDR_FLASH_SECTOR_8     ((uint32_t)0x08080000) // Base @ of Sector 8, 128 Kbytes
  #define ADDR_FLASH_SECTOR_9     ((uint32_t)0x080A0000) // Base @ of Sector 9, 128 Kbytes
  #define ADDR_FLASH_SECTOR_10    ((uint32_t)0x080C0000) // Base @ of Sector 10, 128 Kbytes
  #define ADDR_FLASH_SECTOR_11    ((uint32_t)0x080E0000) // Base @ of Sector 11, 128 Kbytes
  
  // Private constants
  static const uint32_t flash_addr[FLASH_SECTORS] = {
                  ADDR_FLASH_SECTOR_0,
                  ADDR_FLASH_SECTOR_1,
                  ADDR_FLASH_SECTOR_2,
                  ADDR_FLASH_SECTOR_3,
                  ADDR_FLASH_SECTOR_4,
                  ADDR_FLASH_SECTOR_5,
                  ADDR_FLASH_SECTOR_6,
                  ADDR_FLASH_SECTOR_7,
                  ADDR_FLASH_SECTOR_8,
                  ADDR_FLASH_SECTOR_9,
                  ADDR_FLASH_SECTOR_10,
                  ADDR_FLASH_SECTOR_11
  };
  static const uint16_t flash_sector[12] = {
                  FLASH_Sector_0,
                  FLASH_Sector_1,
                  FLASH_Sector_2,
                  FLASH_Sector_3,
                  FLASH_Sector_4,
                  FLASH_Sector_5,
                  FLASH_Sector_6,
                  FLASH_Sector_7,
                  FLASH_Sector_8,
                  FLASH_Sector_9,
                  FLASH_Sector_10,
                  FLASH_Sector_11
  };
  
  uint8_t* flash_helper_get_sector_address(uint32_t fsector) {
          uint8_t *res = 0;
  
          for (int i = 0;i < FLASH_SECTORS;i++) {
                  if (flash_sector[i] == fsector) {
                          res = (uint8_t *)flash_addr[i];
                          break;
                  }
          }
  
          return res;
  }
  
  /*
   * Erase flash page if it is not already erased. This is to save write cycles and
   * prevent the memory from getting erased in case of unstable voltage at boot.
   */
  static uint16_t EE_EraseSectorIfNotEmpty(uint32_t FLASH_Sector, uint8_t VoltageRange) {
  	uint8_t *addr = flash_helper_get_sector_address(FLASH_Sector);
  
  	for (unsigned int i = 0;i < PAGE_SIZE;i++) {
  		if (addr[i] != 0xFF) {
  			return FLASH_EraseSector(FLASH_Sector, VoltageRange);
  		}
  	}
  
  	return FLASH_COMPLETE;
  }
  
  
  