u-boot memory setup

For a PPC7410 processor, I see where the BAT registers are setup in start.S before the MMU is turned on. I cannot fit all resources for my board in the four available DBAT's. I could not find any reference to PTE tables being setup anywhere. Does u-boot setup PTE tables at this point in the code or somewhere later, or does it expect everything to fit in the BAT registers?

Eric