Error: no Image found at 0xbfc90000 , while doing u boot

hi, i was trying to upgrade image using u-boot through tftp client. but on upgrade it show error

Error: no Image found at 0xbfc90000

please help

You usually don't upgrade using tftp.

For whatever device, image, and version used.

actually i build image which doesn't contain mount package and sysupgrade is not working because of this. so i try to upgrade with tftp

Then I guess you're on your own, have fun with your black box.