Keystone II: can't boot kernel with device tree error

Hi,

We just received XTCIEVMK2X Evaluation Module, I used the images from mcsdk_linux_3_00_00_08,

however kernel can't boot successfully, pls see belows.

TCI6638 EVM # tftpboot 0x87000000 uImage-keystone-evm.bin;tftpboot 0x87000000 uImage-keystone-evm.dtb
Using TCI6614-EMAC device
TFTP from server 128.224.163.23; our IP address is 128.224.162.22
Filename 'uImage-keystone-evm.bin'.
Load address: 0x87000000
Loading: #################################################################
         #################################################################
         #################################################################
         ##########################
         665 KiB/s
done
Bytes transferred = 3231992 (3150f8 hex)
Using TCI6614-EMAC device
TFTP from server 128.224.163.23; our IP address is 128.224.162.22
Filename 'uImage-keystone-evm.dtb'.
Load address: 0x87000000
Loading: ###
         585 KiB/s
done
Bytes transferred = 29364 (72b4 hex)
TCI6638 EVM # bootm 0x88000000 - 0x8700000
## Booting kernel from Legacy Image at 88000000 ...
   Image Name:
   Created:      2013-03-31   2:54:51 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    3508256 Bytes = 3.3 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
ERROR: Did not find a cmdline Flattened Device Tree
Could not find a valid device tree

BTW: the uboot version is as follows.U-Boot 2013.01-g84de559 (Feb 07 2013 - 16:25:27)

TCI6638 EVM # version
U-Boot 2013.01-g84de559 (Feb 07 2013 - 16:25:27)
arm-linux-gnueabi-gcc (crosstool-NG linaro-1.13.1-2012.03-20120326 - Linaro GCC 2012.03) 4.6.3
GNU ld (crosstool-NG linaro-1.13.1-2012.03-20120326 - Linaro GCC 2012.03) 2.22

Does it a u-boot issue or something else? thanks!

Regards,

Guoqing