STM32 internal FLASH read and write interface function

Because the internal FLASH is used instead of the external EEPROM, the parameters are placed at 0x08000000+320K of the STM32, of which 20K is the bootloader and 300K is the application.

Principle: First move the contents of the entire FLASH page to RAM, then modify it in RAM, then erase the entire FLASH page, and then write the modified contents to the original Flash page. The following program is debugged and passed.

/*******************************************************************************

* Function Name  : I2C_EE_BufferRead

* Description    : Reads a block of data from the EEPROM.

* Input          :

*                  -RomAddr

*                  -NumByteToRead

* -pRomData

* Output         : None

* Return         : None

*******************************************************************************/

void I2C_EE_BufferRead(u16 RomAddr,u16 NumByteToRead,u8 *pRomData)

{ 

    u32 param_flashbase;

    u8* ptr;

    param_flashbase = 0x8000000+(300+20)*1024;

    ptr = (u8*)(param_flashbase + RomAddr);

    while( NumByteToRead-- >0)

    {

        *pRomData = *ptr; //Just assign value

         printf("0x%x ",*pRomData); 

         pRomData++;

         ptr++;

    }

    return;

} 

/*******************************************************************************

* Function Name  : I2C_EE_BufferWrite

* Description    : Write a block of data to the EEPROM.

* Input          :

*                  -RomAddr

*                  -NumByteToRead

* -pRomData

* Output         : None

* Return         : None

*******************************************************************************/

void I2C_EE_BufferWrite(u8 DeviceType,u8 SlaveAddr,u16 RomAddr,u16 NumByteToWrite,u8 *pRomData)

{

  uint32_t param_flashbase;

  uint32_t  tempaddress;

  uint32_t  startaddress;

  uint32_t FlashAddress;

  uint32_t datasource;

  u8 buf1[PAGE_SIZE];

  u8 buf2[PAGE_SIZE];

  u32 pagenumber = 0x0;

  u32 EraseCounter = 0x0;

  u32 i = 0;

  FLASH_Status FLASHStatus = FLASH_COMPLETE;

  param_flashbase = 0x8000000+(300+20)*1024;

  startaddress=tempaddress = param_flashbase+RomAddr;

 /*********************The start pointer is not at the beginning of the Flash page*********************/

 if( (tempaddress%PAGE_SIZE) != 0)

 {   printf("startptr  not in Page head \r\n");

  if( ((startaddress%PAGE_SIZE)+NumByteToWrite) > PAGE_SIZE ) /*Out of one page range

  {

      I2C_EE_BufferRead(0,0,(tempaddress-(tempaddress % PAGE_SIZE)),PAGE_SIZE,buf1); /*Read the contents of the page where the start address is located into memory buf1

      memcpy(buf1+(tempaddress % PAGE_SIZE),pRomData,PAGE_SIZE-(tempaddress % PAGE_SIZE)); /*Overwrite the data to be written into buf1

      while(  FLASHStatus == FLASH_ErasePage(tempaddress)   )       /*buf1写入到Flash

     {

         i=PAGE_SIZE/4;

         datasource = (uint32_t)buf1;

         FlashAddress = tempaddress-(tempaddress % PAGE_SIZE);

         while(i-- >0)

         {

             FLASH_ProgramWord(FlashAddress,*(uint32_t*)datasource);

             if (*(uint32_t*)FlashAddress != *(uint32_t*)datasource)           

         {

          printf("I2C_EE_BufferWrite error!\r\n");

          return ;

          }

          datasource += 4;

          FlashAddress += 4;    

    }

    break;

   }

   NumByteToWrite -= PAGE_SIZE-(startaddress % PAGE_SIZE); The number of bytes to be written minus the number of bytes of data to be overwritten

   tempaddress += PAGE_SIZE-(tempaddress % PAGE_SIZE); /*Set the ptr pointer to the start of the next page

   if((NumByteToWrite % PAGE_SIZE) != 0) /*The end pointer is not at the beginning of the Flash page

   {

       //Read 1 PAGE of data into memory, modify, and then write it in

       I2C_EE_BufferRead(0,0,tempaddress,PAGE_SIZE,buf2);

       memcpy(buf2,pRomData+PAGE_SIZE-startaddress%PAGE_SIZE+NumByteToWrite-NumByteToWrite%PAGE_SIZE,(NumByteToWrite%PAGE_SIZE));

    while( FLASHStatus == FLASH_ErasePage( tempaddress+NumByteToWrite) ) /*Write buf2 to Flash*

    {

        i=PAGE_SIZE/4;

        datasource = (uint32_t)buf2;

        FlashAddress = (tempaddress+NumByteToWrite-(NumByteToWrite % PAGE_SIZE)); /*Head of the last address pointer

        while(i-- >0)

       {

           FLASH_ProgramWord(FlashAddress,*(uint32_t*)datasource);

           if (*(uint32_t*)FlashAddress != *(uint32_t*)datasource)            

           {

                printf("I2C_EE_BufferWrite error!\r\n");

                return ;

            }

            datasource += 4;

            FlashAddress += 4;          

      }

     break;

    }      

   }

   NumByteToWrite -= NumByteToWrite % PAGE_SIZE;

   // Erase Flash

    pagenumber = NumByteToWrite/PAGE_SIZE;

     for (EraseCounter = 0; (EraseCounter < pagenumber) && (FLASHStatus == FLASH_COMPLETE); EraseCounter++)

   {

         FLASHStatus = FLASH_ErasePage( tempaddress + PAGE_SIZE*EraseCounter );

   }

   //Write Flash

   datasource = *(uint32_t *)(pRomData+ PAGE_SIZE-(startaddress % PAGE_SIZE)  );

   FlashAddress = tempaddress;

   while( pagenumber-- > 0 )

   {

    i=PAGE_SIZE/4;

    while(i -- >0)

    {

            FLASH_ProgramWord(FlashAddress,*(uint32_t*)datasource);

            if (*(uint32_t*)FlashAddress != *(uint32_t*)datasource)

           {

               printf("I2C_EE_BufferWrite error!\r\n");

               return ;

           }

           datasource += 4;

           FlashAddress += 4;

    }

   }

  }

  else /*The content written does not exceed the scope of one page

  {

   printf("FlashWrire --in one page \r\n");

   I2C_EE_BufferRead(0,0,(startaddress-(startaddress % PAGE_SIZE)),PAGE_SIZE,buf1); /*Read the contents of the page where the start address is located into memory buf1   

   memcpy( (buf1+(tempaddress % PAGE_SIZE)),pRomData, NumByteToWrite ); /*Overwrite the data to be written into buf1

   while(  FLASHStatus == FLASH_ErasePage(tempaddress)   )

   {

      i=PAGE_SIZE/4;

      datasource = (uint32_t)buf1;

      FlashAddress = tempaddress-(tempaddress % PAGE_SIZE);

      while(i-- >0)

      {

        FLASH_ProgramWord(FlashAddress,*(uint32_t*)datasource);

        if (*(uint32_t *)FlashAddress != *(uint32_t *)datasource) /*Read the data in the Flash to see if it is written correctly

        {

               printf("I2C_EE_BufferWrite error!\r\n");

               return ;

        }

        datasource += 4;

        FlashAddress += 4;    

    }

    break;

   }

  }

 }

/*******************The starting pointer is at the beginning of the Flash page****************************/

 else

 { printf("startptr  in Page head \r\n");

  if((NumByteToWrite % PAGE_SIZE) != 0)

  {

    //Read 1 PAGE of data into memory, modify, and then write it in

   I2C_EE_BufferRead(0,0,(u16)(tempaddress+NumByteToWrite-(NumByteToWrite % PAGE_SIZE)),PAGE_SIZE,buf1);

   printf("already copy to bug1 \r\n");

   memcpy(buf1,pRomData+NumByteToWrite-(NumByteToWrite % PAGE_SIZE),(NumByteToWrite % PAGE_SIZE));

//end of debug

  }

  // Erase Flash

  if( (NumByteToWrite%PAGE_SIZE) == 0 )

  {

       pagenumber = NumByteToWrite/PAGE_SIZE;

  }

  else

  {

       pagenumber = NumByteToWrite/PAGE_SIZE + 1;

  }

   for (EraseCounter = 0; (EraseCounter < pagenumber) && (FLASHStatus == FLASH_COMPLETE); EraseCounter++)

  {

        FLASHStatus = FLASH_ErasePage(startaddress + (PAGE_SIZE * EraseCounter));

  }

  //Write Flash

  if( pagenumber == 1) /* Only one page

  {   

   i=PAGE_SIZE/4;

   datasource = (uint32_t)buf1;

   FlashAddress = startaddress;

   while(i-- >0)

   {

        FLASH_ProgramWord(FlashAddress,*(uint32_t *)datasource);

        if (*(uint32_t *)FlashAddress != *(uint32_t *)datasource)

        {

            printf("I2C_EE_BufferWrite error!\r\n");

            return ;

        }

        datasource +=4;

        FlashAddress +=4;

   }  

  }

  else /*When there are many pages, write the previous page first and buf1 last

  {

   while( pagenumber-- > 1 )

   {

    datasource = (u32)pRomData;

    FlashAddress = startaddress;

    i=PAGE_SIZE/4;

    while(i -- >0)

    {

            FLASH_ProgramWord( FlashAddress, *(uint32_t *)datasource );

            if (*(uint32_t *)FlashAddress != *(uint32_t *)datasource)

            {

                  printf("I2C_EE_BufferWrite error!\r\n");

                  return ;

            }

            datasource += 4;

            FlashAddress += 4;

    } 

   }

   //Write the following pages

   datasource = (uint32_t)buf1;

   FlashAddress = startaddress+(pagenumber-1)*PAGE_SIZE;

   i=PAGE_SIZE/4;

   while(i -- >0)

   {

       FLASH_ProgramWord( FlashAddress, *(uint32_t *)datasource );

       if (*(uint32_t *)FlashAddress != *(uint32_t *)datasource)

       {

             printf("I2C_EE_BufferWrite error!\r\n");

             return ;

       }

       datasource += 4;

       FlashAddress += 4;

   } 

  }    

 } 

}