query regarding access of physical memory from user space

Akash kaul akashkaul13 at yahoo.com
Sat Feb 12 15:53:37 EST 2005


Some more doubts about the same thing.

As I am aware, the MPC8260 does not have a separate
I/O address space. 
> Yes,The MPC8260 I/O address space is mapped into 
> the Processors address space itself i,e the 256 Kb
> Internal memory which can be located anywhere in the
> 4 GB adress space using the IMMR register

with reference to my earlier mail, when do we need to
use ioremap() and when
do we need to use request_mem_region()? Or do we need
to use both in a
particular sequence?

> For the MPC8260 you can access the I/O region  
> directly without an need for mapping.U can access 
> it thru the IMMR base address value.And specific 
> registers can be accessed by adding the register 
> offset to this value

Also, if I just do an ioremap(), can I directly access
those remapped
addresses with inb()/outb() or writeb()/readb()? Or is
something more to be
done prior to accessing it?

> u dont have to do an ioremap


Vijay Padiyar


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