Dear wang yongkang,
Have you finished the u-boot porting by now? If yes, you can build and compile an OS Firmware for MFG. In the attachment I give you a document about the porting u-boot, it is on android 4.2. You can refer to it.
Have a great day,
Dan
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------