不能为beagle骨黑色(BB-black)启动openwrt

I am trying porting openwrt to BBB. And as shown in title, I cannot boot-up openwrt on BeagleBone Black. If someone have tried to do something on BeagleBone Black(BBB), you must know there are two partitions in its flash or SD card. The first partition is FAT32 as a boot partition, the second partition is Ext4 as linux root file system.I am trying porting openwrt to BBB. And as show