Android 7 for bpi-m2z

Hi. I have downloaded the Android 7 source code for bpi m2 +. I have successfully compiled and obtained the image for bpi M2Z however it does not boot. the console shows file system error and gets stuck on boot logo. am I missing some configuration? if i compile for M2 + it works fine. Any help please. i want to build image for bpi M2Z. Thank you very much in advance. Alleiny.