zydwh 发表于 2015-8-17 12:35
修改的地方之一：stm32f4xx.h里面的HSE_VALUE，系统默认采用外部8M晶振，所以 #define HSE_VALUE ...

请问

/**
* @brief In the following line adjust the value of External High Speed oscillator (HSE)
   used in your application
   
   Tip: To avoid modifying this file each time you need to use different HSE, you
        can define the HSE value in your toolchain compiler preprocessor.
  */           

#if !defined  (HSE_VALUE)
  #define HSE_VALUE    ((uint32_t)8000000) /*!< Value of the External oscillator in Hz */
  
#endif /* HSE_VALUE */

他这里的tips，说如果要避免每次改时钟都修改，就在编译链里解决，请问具体怎么做呢，谢谢。