[U-Boot] what/where is image_entry()

[Haleigh Novak]

Hello All, 

Please forgive the uber-beginner question but I can not find anything related online,
I have been digging around in the uboot source and I stumbled on the image_entry()
function; sometimes it has parameters and sometimes it does not. I am unable to 
locate the source(s) of the function, so I can not see how it works. Could someone
explain what image_entry() actually does or at least point me to where it is defined?

Thank you for your time.

HN