> Is there in relation to Big/Little endian mode any performance penalties =
> on a ARM920T core?
> I noticed that on some of the Intel XScale processors only Big endian =
> mode is allowed, so I figure the dual compatible endian mode processors =
> has to do some conversion internally in one of the modes not native to =
> the execution unit.

For the core there are no performance penalties.  However, ARM chips often 
appear as part of a larger ASIC and peripherals in that ASIC may be 
restricted to one Endian configuration.