STM32F4(Flash读保护)

1，目的

        在实际的产品发布中，如果不对储存在单片机Flash中的程序做一些保护的话，就有可能被一些不法公司，通过仿真器（J-Link，ST-Link等）把Flash中的程序读取回来，得到bin文件或hex文件，然后去山寨产品。所以我们需要对程序进行保护，一种比较简单可靠的方法就是把Flash设置成读保护。

2，开发环境

        1，适用芯片：STM32F4全部芯片

        2，固件库：STM32F4xx_DSP_StdPeriph_Lib_V1.8.0

        3，IDE：MDK517

3，程序源码

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

 * Function:    Flash_EnableReadProtection 

 * Description: Enable the read protection of user flash area. 

 * Input: 

 * Output: 

 * Return:      1: Read Protection successfully enable 

 *              2: Error: Flash read unprotection failed 

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

uint32_t Flash_EnableReadProtection(void)  

{  

  /* Returns the FLASH Read Protection level. */  

  if( FLASH_OB_GetRDP() == RESET )  

  {  

    /* Unlock the Option Bytes */  

    FLASH_OB_Unlock();  

    /* Sets the read protection level. */  

    FLASH_OB_RDPConfig(OB_RDP_Level_1);  

    /* Start the Option Bytes programming process. */    

    if (FLASH_OB_Launch() != FLASH_COMPLETE)  

    {  

      /* Disable the Flash option control register access (recommended to protect  

         the option Bytes against possible unwanted operations) */  

      FLASH_OB_Lock();  

      /* Error: Flash read unprotection failed */  

      return (2);  

    }  

    /* Disable the Flash option control register access (recommended to protect  

       the option Bytes against possible unwanted operations) */  

    FLASH_OB_Lock();  

    /* Read Protection successfully enable */  

    return (1);  

  }  

  /* Read Protection successfully enable */  

  return (1);  

}  

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

 * Function:    Flash_DisableReadProtection 

 * Description: Disable the read protection of user flash area. 

 * Input: 

 * Output: 

 * Return:      1: Read Protection successfully disable 

 *              2: Error: Flash read unprotection failed 

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

uint32_t Flash_DisableReadProtection(void)  

{  

  /* Returns the FLASH Read Protection level. */  

  if( FLASH_OB_GetRDP() != RESET )  

  {  

    /* Unlock the Option Bytes */  

    FLASH_OB_Unlock();  

    /* Sets the read protection level. */  

    FLASH_OB_RDPConfig(OB_RDP_Level_0);  

    /* Start the Option Bytes programming process. */    

    if (FLASH_OB_Launch() != FLASH_COMPLETE)  

    {  

      /* Disable the Flash option control register access (recommended to protect  

         the option Bytes against possible unwanted operations) */  

      FLASH_OB_Lock();  

      /* Error: Flash read unprotection failed */  

      return (2);  

    }  

    /* Disable the Flash option control register access (recommended to protect  

       the option Bytes against possible unwanted operations) */  

    FLASH_OB_Lock();  

    /* Read Protection successfully disable */  

    return (1);  

  }  

  /* Read Protection successfully disable */  

  return (1);  

}