let's see if someone answers this before RCN 
... at robert's
wiki page here:
https://eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-Bootloader:U-Boot
robert describes using u-boot's "am335x_evm_defconfig" as the basis
for building u-boot for the BBB, even though u-boot has an apparently
more specific "am335x_boneblack_defconfig" file.
  anyone know why the evm-flavoured file is used as opposed to the
"boneblack" one? i know it works, i'm just curious as to the choice.
rday