2440没有从SD卡启动的功能，但通过在SD卡里建立文件系统，可以实现2440从SD卡启动，附件是我对2440SD卡启动的理解。-2440 does not boot from the SD card functionality, but through the establishment of the SD card file system, can boot from the SD card 2440, annex I to the 2440SD card start understandi