就改过这个:
Modify "user_config.h" so the board uses interrupted serial device as
a standard I/O device. Following is example for TWRK60N512/TWRK60F120M:
#define BSPCFG_ENABLE_ITTYF 1
#define BSP_DEFAULT_IO_CHANNEL_DEFINED
#define BSP_DEFAULT_IO_CHANNEL "ittyf:"