1. .Pc connection the device via Ethernet cable,and enter the device through the serial port.
2.  Restart the device, and at the same time hold down the ctrl+I 
3. On PC open the tftp server and set the directory to upgrade file.

Reset to factory default ?
Reset to factory default ?

4. Please input the following command:
Command 1:
fmcsetenv -p STARTUP "fmcifconfig eth0 -addr=10.1.1.24 -mask=255.255.255.0 -gw=10.1.1.1;fmce -h 0xba000008 0000;fmce -h 0xba000000 00b7;fmce -h 0xba00000a 2"
Command 2:exit
Command 3:fmcflash -noheader IPtftp:ghncfe2.0.bin flash0.boot
Command 4:fmcsetenv -p STARTUP "fmcload -raw -addr=0x80800000 -max=0x1400000 flash0.ramdisk:;fmcboot -z -elf flash0.os:"

Command 5: fmcsetfb 28b0cc110014032.000R3A0058116a8bf0e32
Command 6: exit

Upgrade complete