changeset 76:f1c9a51e368a

Add EEPROM emulation from AN2594. Fix emulated EEPROM size on large parts.
author Daniel O'Connor <darius@dons.net.au>
date Mon, 22 Apr 2013 23:17:40 +0930
parents 85f16813c730
children 7dd28b96a716
files BSDmakefile STM32F10x_128k_20k_flash.ld STM32F10x_512k_64k_flash.ld eeprom.c eeprom.h main.c
diffstat 6 files changed, 753 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/BSDmakefile	Thu Apr 18 22:44:52 2013 +0930
+++ b/BSDmakefile	Mon Apr 22 23:17:40 2013 +0930
@@ -4,6 +4,7 @@
 		comm.c \
 		core_cm3.c \
 		delay.c \
+		eeprom.c \
 		fatfs_sd.c \
 		ff.c \
 		flash.c \
@@ -23,7 +24,7 @@
 
 #SRCS+=		ccsbcs.c
 
-STM32LIBS=	usart gpio rcc rtc pwr bkp fsmc spi tim i2c crc sdio dma
+STM32LIBS=	usart gpio rcc rtc pwr bkp fsmc spi tim i2c crc sdio dma flash
 
 .for f in ${STM32LIBS}
 SRCS+=		stm32f10x_${f}.c
--- a/STM32F10x_128k_20k_flash.ld	Thu Apr 18 22:44:52 2013 +0930
+++ b/STM32F10x_128k_20k_flash.ld	Mon Apr 22 23:17:40 2013 +0930
@@ -15,6 +15,7 @@
 {
 	RAM      (RWX) : ORIGIN = 0x20000000+0, LENGTH = 20K-0
 	EXTSRAM  (RWX) : ORIGIN = 0x68000000, LENGTH = 0
+	/* Page size is 1k for this device and we have 2 pages of emulated EEPROM */
 	FLASH    (RX)  : ORIGIN = 0x08000000+0, LENGTH = 128K-2K-0
 	EEMUL    (RWX) : ORIGIN = 0x08000000+128k-2k, LENGTH = 2k
 	FLASHB1  (RX)  : ORIGIN = 0x00000000, LENGTH = 0
--- a/STM32F10x_512k_64k_flash.ld	Thu Apr 18 22:44:52 2013 +0930
+++ b/STM32F10x_512k_64k_flash.ld	Mon Apr 22 23:17:40 2013 +0930
@@ -15,8 +15,9 @@
 {
 	RAM      (RWX) : ORIGIN = 0x20000000+0, LENGTH = 64K-0
 	EXTSRAM  (RWX) : ORIGIN = 0x68000000, LENGTH = 0
-	FLASH    (RX)  : ORIGIN = 0x08000000+0, LENGTH = 512K-2K-0
-	EEMUL    (RWX) : ORIGIN = 0x08000000+512k-2k, LENGTH = 2k
+	/* Page size is 2k for this device and we have 2 pages of emulated EEPROM */
+	FLASH    (RX)  : ORIGIN = 0x08000000+0, LENGTH = 512K-4K-0
+	EEMUL    (RWX) : ORIGIN = 0x08000000+512k-4k, LENGTH = 4k
 	FLASHB1  (RX)  : ORIGIN = 0x00000000, LENGTH = 0
 	EXTMEMB0 (RX)  : ORIGIN = 0x00000000, LENGTH = 0
 	EXTMEMB1 (RX)  : ORIGIN = 0x00000000, LENGTH = 0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/eeprom.c	Mon Apr 22 23:17:40 2013 +0930
@@ -0,0 +1,663 @@
+/**
+  ******************************************************************************
+  * @file    EEPROM_Emulation/src/eeprom.c
+  * @author  MCD Application Team
+  * @version V3.1.0
+  * @date    07/27/2009
+  * @brief   This file provides all the EEPROM emulation firmware functions.
+  ******************************************************************************
+  * @copy
+  *
+  * 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 2009 STMicroelectronics</center></h2>
+  */
+/** @addtogroup EEPROM_Emulation
+  * @{
+  */
+
+/* Includes ------------------------------------------------------------------*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "eeprom.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 */
+const uint16_t VirtAddVarTab[NumbOfVar] = { 1000, 1001, 1002 };
+
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+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);
+
+/**
+  * @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 = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
+        /* 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 = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
+        /* 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 < NumbOfVar; 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 = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
+        /* 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 = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
+        /* 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 = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
+        /* 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 < NumbOfVar; 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 = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
+        /* 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 = 0x08010000, PageStartAddress = 0x08010000;
+
+  /* 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 PAGE0 and PAGE1 and writes VALID_PAGE header to PAGE0
+  * @param  None
+  * @retval Status of the last operation (Flash write or erase) done during
+  *         EEPROM formating
+  */
+
+FLASH_Status EE_Format(void)
+{
+  FLASH_Status FlashStatus = FLASH_COMPLETE;
+
+  /* Erase Page0 */
+  FlashStatus = FLASH_ErasePage(PAGE0_BASE_ADDRESS);
+
+  /* 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 = FLASH_ErasePage(PAGE1_BASE_ADDRESS);
+
+  /* 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 (PAGE0 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 = 0x08010000, PageEndAddress = 0x080107FF;
+
+  /* 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 = 0x080103FF, OldPageAddress = 0x08010000;
+  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 address where variable will be taken from */
+    OldPageAddress = PAGE1_BASE_ADDRESS;
+  }
+  else if (ValidPage == PAGE0)  /* Page0 valid */
+  {
+    /* New page address where variable will be moved to */
+    NewPageAddress = PAGE1_BASE_ADDRESS;
+
+    /* Old page address where variable will be taken from */
+    OldPageAddress = PAGE0_BASE_ADDRESS;
+  }
+  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 < NumbOfVar; 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 = FLASH_ErasePage(OldPageAddress);
+  /* 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;
+}
+
+void
+FLASH_UnlockClear(void) {
+    FLASH_Unlock();
+    FLASH_ClearFlag(FLASH_FLAG_BSY | FLASH_FLAG_EOP | FLASH_FLAG_PGERR | FLASH_FLAG_WRPRTERR);
+}
+
+void
+EE_Cmd(int argc, char **argv) {
+    uint16_t	adr, val, err;
+    
+    if (argc == 0) {
+	fputs("No command specified\n", stdout);
+	return;
+    }
+
+    if (!strcmp(argv[0], "in")) {
+	FLASH_UnlockClear();
+	printf("Init returned %d\n", EE_Init());
+	FLASH_Lock();
+    } else if (!strcmp(argv[0], "fm")) {
+	FLASH_UnlockClear();
+	printf("Format returned %d\n", EE_Format());
+	FLASH_Lock();
+    } else if (!strcmp(argv[0], "rd")) {
+	if (argc != 2) {
+	    fputs("Incorrect number of arguments\n", stdout);
+	    return;
+	}
+	adr = atoi(argv[1]);
+	err = EE_ReadVariable(adr, &val);
+	printf("Read 0x%04x => 0x%04x (status %d)\n", adr, val, err);
+    } else if (!strcmp(argv[0], "wr")) {
+	if (argc != 3) {
+	    fputs("Incorrect number of arguments\n", stdout);
+	    return;
+	}
+	adr = atoi(argv[1]);
+	val = atoi(argv[2]);
+	FLASH_UnlockClear();
+	err = EE_WriteVariable(adr, val);
+	FLASH_Lock();
+	printf("Write 0x%04x <= 0x%04x (status %d)\n", adr, val, err);
+    } else {
+	fputs("Unknown command\n", stdout);
+    }
+}
+
+/**
+  * @}
+  */
+
+/******************* (C) COPYRIGHT 2009 STMicroelectronics *****END OF FILE****/
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/eeprom.h	Mon Apr 22 23:17:40 2013 +0930
@@ -0,0 +1,81 @@
+/**
+  ******************************************************************************
+  * @file    EEPROM_Emulation/inc/eeprom.h
+  * @author  MCD Application Team
+  * @version V3.1.0
+  * @date    07/27/2009
+  * @brief   This file contains all the functions prototypes for the EEPROM
+  *          emulation firmware library.
+  ******************************************************************************
+  * @copy
+  *
+  * 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 2009 STMicroelectronics</center></h2>
+  */
+
+/* Define to prevent recursive inclusion -------------------------------------*/
+#ifndef __EEPROM_H
+#define __EEPROM_H
+
+/* Includes ------------------------------------------------------------------*/
+#include "stm32f10x.h"
+
+/* Exported constants --------------------------------------------------------*/
+/* Define the STM32F10Xxx Flash page size depending on the used STM32 device */
+#if defined (STM32F10X_LD) || defined (STM32F10X_MD)
+  #define PAGE_SIZE  (uint16_t)0x400  /* Page size = 1KByte */
+#elif defined (STM32F10X_HD) || defined (STM32F10X_CL)
+  #define PAGE_SIZE  (uint16_t)0x800  /* Page size = 2KByte */
+#endif
+
+/* EEPROM start address in Flash */
+extern uint32_t _seemul;
+#define EEPROM_START_ADDRESS  ((uint32_t)&_seemul) /* start of emulated EEPROM def'd in linker-script */
+
+/* Pages 0 and 1 base and end addresses */
+#define PAGE0_BASE_ADDRESS      ((uint32_t)(EEPROM_START_ADDRESS + 0x000))
+#define PAGE0_END_ADDRESS       ((uint32_t)(EEPROM_START_ADDRESS + (PAGE_SIZE - 1)))
+
+#define PAGE1_BASE_ADDRESS      ((uint32_t)(EEPROM_START_ADDRESS + PAGE_SIZE))
+#define PAGE1_END_ADDRESS       ((uint32_t)(EEPROM_START_ADDRESS + (2 * PAGE_SIZE - 1)))
+
+/* Used Flash pages for EEPROM emulation */
+#define PAGE0                   ((uint16_t)0x0000)
+#define PAGE1                   ((uint16_t)0x0001)
+
+/* No valid page define */
+#define NO_VALID_PAGE           ((uint16_t)0x00AB)
+
+/* Page status definitions */
+#define ERASED                  ((uint16_t)0xFFFF)     /* PAGE is empty */
+#define RECEIVE_DATA            ((uint16_t)0xEEEE)     /* PAGE is marked to receive data */
+#define VALID_PAGE              ((uint16_t)0x0000)     /* PAGE containing valid data */
+
+/* Valid pages in read and write defines */
+#define READ_FROM_VALID_PAGE    ((uint8_t)0x00)
+#define WRITE_IN_VALID_PAGE     ((uint8_t)0x01)
+
+/* Page full define */
+#define PAGE_FULL               ((uint8_t)0x80)
+
+/* Variables' number */
+#define NumbOfVar               ((uint8_t)0x03)
+
+/* Exported types ------------------------------------------------------------*/
+/* Exported macro ------------------------------------------------------------*/
+/* Exported functions ------------------------------------------------------- */
+uint16_t EE_Init(void);
+uint16_t EE_ReadVariable(uint16_t VirtAddress, uint16_t* Data);
+uint16_t EE_WriteVariable(uint16_t VirtAddress, uint16_t Data);
+FLASH_Status EE_Format(void);
+void	EE_Cmd(int argc, char **argv);
+
+#endif /* __EEPROM_H */
+
+/******************* (C) COPYRIGHT 2009 STMicroelectronics *****END OF FILE****/
--- a/main.c	Thu Apr 18 22:44:52 2013 +0930
+++ b/main.c	Mon Apr 22 23:17:40 2013 +0930
@@ -14,6 +14,7 @@
 #include "1wire.h"
 #include "comm.h"
 #include "delay.h"
+#include "eeprom.h"
 #include "flash.h"
 #include "hw.h"
 #include "lcd.h"
@@ -360,6 +361,8 @@
 	    assert(0 == 1);
 	} else if (!strcmp("sd", argv[0])) {
 	    sd_cmd(argc - 1, argv + 1);
+	} else if (!strcmp("ee", argv[0])) {
+	    EE_Cmd(argc - 1, argv + 1);
 	} else if (!strcmp("zz", argv[0])) {
 	    NVIC_SystemReset();
 	} else {