[U-Boot] at91sam source tree to use

Hello, I would like to customize an u-boot source tree to use in an at91sam9263 embedded CPU board. But I am in doubt if I should use the main u-boot source tree or the at91 fork tree (and now orphaned one) ? What are the main differences between the main and at91 forked source trees ? I saw that a lot of at91sam9263 related code exists in tha main tree...

thanks, Moises