[U-Boot-Users] Can MPC processors boot though the IMMR is at 0x0 (default configuration)?

[Peter Asemann <peter.asemann@web.de>]

I'm going to try booting u-boot on a custom MPC875 board.
It has flash at the boot memory bank (bank 0).
It has no circuit to pull up pin 7/8 of the MPC data bus at processor
start, so (the manual says) the IMMR/the internal memory is configured
to reside at 0x0.

I think this causes the internal memory to shadow the boot flash, which
should prevent the board from booting. At least the internal memory
shadows the boot memory bank in the debugger.
That's why I was planning to solder some circuit to the board to
configure the internal memory to be somewhere else at startup.

The board designer says he can't believe the MPC875 default
configuration is like that boards which use it can't boot.

So - does someone incidentally know something about MPC default
configurations and if MPCs can boot though the IMMR is at 0x0?
And if they can't, why the IMMR is at 0x0 by default?

Thanks for reading,

Peter Asemann