[U-Boot] sequoia board can't run itself

[Jason.Sun]

myfrends,
 
I am porting a boot from sequoia.
I have use the BDI3000 to load the u-boot.bin and flash to norflash.
I can trace the codes by BDI3000 and receive the u-boot info from uart as following.
but when I try to power on and run the codes itself but not use BDI3000 to send "go".
there are  not any characters from the uart port.
 
I have no idea to find the bug. have any one can give some advice?

Best Regerd.
Jason