Hello!

I hope you all can help me with understanding.

Some (all?) PowerPC implementations have a bit in the MSR to tell the core to 
run in either 32 bit or 64 bit mode. At least my core "in front of me" has 
this. It is a 64 bit implementation and I need to be able to boot both 32/64 
bit OSes (with same U-Boot).

My initial hope was that 32 bit programs would run in 64 bit mode. This to ease 
up my U-Boot implementation. And as far as I know you do not change the 
bootloader when you switch between a 32 bit OS and a 64 bit OS on your PC?! But 
of course that bit in the MSR is there for a reason :)

So, my guess how to solve this is that bootloaders are usually 32 bit to be 
backward compatible and let the OS decide to step up to 64-bit or not. Is this 
true and the general rule? 

But I feel there are occassions when a 64 bit bootloader is nice, to access 
more memory at once for instance. 
Do you have any recommendations for me?

Thanks
BR
Robert

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