[U-Boot] Adding a new board to the configuration

Hi all-

I'd like to add a new custom board configuration to the u-boot build.

Which files have to be created and/or patched to add a new board to build system?

Our design uses the MPC8568E CPU, so I suppose, I can use a lot of present code coming from parameters like "ppc" and "mpc85xx".

Of course I am taking a look at other configurations, but I'd like to know how to set it up from scratch, especially to getting to know the essentials.

So, what is needed for that later I can give it a "make MYCOOLBOARD_config" followed by "make all"?

Cheers Matthias