[U-Boot-Users] How to find out u-boot version

Hi I have old u-boot sources and I am comparing them against the latest u-boot sources. How can I find out the version of the old u-boot sources when I dont know how long and from where they have been downloaded? I have checked the README file but the version is never mentioned there. I know it sounds like a dumb question, please enlighten.

-pharaoh.