[U-Boot] How to specify new file size and CRC32 checksum for modified Linux Kernel Image?

[A.W.C.]

U-boot 2009.03

How to specify in U-boot file the new file size and CRC32 checksum for modified Linux Kernel Image?
So that avoid Error message "Verifying Checksum ... Bad Data CRC"  when u-boot load linux kernel.

Regards,
Alex