http://www.eeworld.com.cn/mcu/article_2018042338836.html
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);
}