#ifdef USE_STM32100B_EVAL //如果是定义了USE_STM32100B_EVAL
#include "stm32100b_eval/stm32100b_eval.c"//就执行这句
#elif defined USE_STM3210B_EVAL//否则如果是定义了USE_STM3210B_EVAL
#include "stm3210b_eval/stm3210b_eval.c" //就执行这句
#elif defined USE_STM3210E_EVAL//否则如果是定义了USE_STM3210E_EVAL
#include "stm3210e_eval/stm3210e_eval.c"//就执行这句
#elif defined USE_STM3210C_EVAL //同上
#include "stm3210c_eval/stm3210c_eval.c" //同上
#else //以上全部不是 执行下面 #error "Please select first the STM32 EVAL board to be used (in stm32_eval.h)"