stm32 IAP+USART 实现firmware update记录

平台stm32l072

基于ST官网的例程修改 AN4657

1、示例代码中的Ymodem协议 win7的超级终端支持，手册里提到的Tera Term 新版本的Ymodem不支持

2、示例代码中Ymodem接收部分的RxTimeout给的是1S，UR设置过小波特率，会有接收数据不完整的问题，可改为2S。

3、flash的参数地址修改

/* Define the address from where user application will be loaded.
   Note: this area is reserved for the IAP code                  */
#define FLASH_PAGE_STEP         FLASH_PAGE_SIZE           /* Size of page : 2 Kbytes */
#define APPLICATION_ADDRESS     (uint32_t)0x08008000      /* Start user code address: ADDR_FLASH_PAGE_8 */

/* Notable Flash addresses */
#define FLASH_START_BANK1             FLASH_BASE
#define WORDS_IN_HALF_PAGE            ((uint32_t)16)
#define FLASH_HALF_PAGE_SIZE          ((uint32_t)WORDS_IN_HALF_PAGE*4)
#define FLASH_LAST_SECTOR_BANK1       ((uint32_t)0x08017000)
#define FLASH_LAST_PAGE_BANK1         ((uint32_t)0x08017F80)
#define FLASH_END_BANK1               FLASH_BANK1_END
#define FLASH_START_BANK2             FLASH_BANK2_BASE
#define USER_FLASH_END_ADDRESS        ((uint32_t)0x08030000)
#define FLASH_BANK1_MASK              ((uint32_t)0xF0FFFFFF)

/* Define the user application size */
#define USER_FLASH_SIZE               ((uint32_t)0x000030000) /* Small default template application */

4、flash写入建议使用HAL_FLASH_Program() ，示例代码中的HAL_FLASHEx_HalfPageProgram()在写入时，会有FLASH_FLAG_FWWERR的错误。原因未知。代码修改如下：

if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, destination, *p_actual) == HAL_OK)
{
      /* Check if flash content matches memBuffer */
      if ((*(uint32_t*)(destination)) != *p_actual)
      {
        /* flash content doesn't match memBuffer */
        status = FLASHIF_WRITINGCTRL_ERROR;
        break;
      }
		
      /* Increment the memory pointers */
      destination += 4;
      p_actual += 1;
}
else
{
    status = FLASHIF_WRITING_ERROR;
}

5、示例代码中Ymodem上传时会用到APP文件大小，文件大小记录在eeprom为好。

6、Int2Str (astring, length); 注意astring使用前置0.