Resolved! The function f_read of FATFS reads nothing when FreeRTOS is used.
My mcu is H743, the MDMA is enable for SD. The FATFS is used to operate file system. CubeMX is used to generate template code.Without the FreeRTOS, both of the FATFS functions f_write() and f_read () work correctly. But when the FreeRTOS is used, f_w...