[U-Boot-Users] MMU and Linux kernel booting

llandre r&d2 at dave-tech.it
Tue Dec 7 15:59:10 CET 2004

Hi all,

I have a couple of questions regarding the MMU.
I'm working with a custom hardware based on Cirrus Logic EP9315 processor.
As the on-chip SDRAM controller is unable to map the memory in
contiguous regions, I have to use the MMU to do that.
On the other hand Linux requires that MMU is off when it boots
1) In my understanding the function cleanup_before_linux 
(cpu/arm920t/cpu.c) is supposed to
perform this opearation but it does not. Is this the right place to turn 
MMU off?
2) The second questions refers to memory tags. They should describe _physical_
mapping, right? If this is correct, the bd->bi_dram fields should be extended
in order to describe both physical and virtual regions. Does it make sense?

Thanks in advance,


DAVE Electronics System House - R&D Department
web:   http://www.dave-tech.it
email: r&d2 at dave-tech.it

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