Accessing physical memory

Accessing physical memory

[Antonio Di Bacco]

How can I access the physical memory? Can I MMAP for example /dev/mem? Is 
there a simpler way?

Bye,
Antonio. 

Re: Accessing physical memory

[Arnd Bergmann]

On Saturday 08 April 2006 23:52, Antonio Di Bacco wrote:
> How can I access the physical memory? Can I MMAP for example /dev/mem? Is 
> there a simpler way?

/dev/mem access is the most simple way. A cleaner solution is usually to
write your own simple character device driver for the stuff you want to
access in memory.

Depending on why you want to access memory, slram may be the right
driver, e.g. when you want to store a file system there.

	Arnd <><

Re: Accessing physical memory

[dwh]

Quoting Antonio Di Bacco <antonio.dibacco@aruba.it>:

> How can I access the physical memory? Can I MMAP for example /dev/mem? Is
> there a simpler way?
>

Hi Antonio,

What would you like to do? If you just want some arbitrary
page of memory, then look at the 'nopage' example in Rubini,
or ask me and I'll send you some code.

If you want a specific memory location, then you'll need
to claim and ioremap the memory, and again, I can give you
some code.

So, explain a little more and I can help.

Dave


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RE: Accessing physical memory

[Fillod Stephane]

Antonio Di Bacco wrote:
>How can I access the physical memory? Can I MMAP for example /dev/mem?
Is=20
>there a simpler way?

Your question is a linuxppc-embedded FAQ.
It is documented in Denx's FAQ[1], and accessible through shorter
URL[2].
For more information, please follow this thread[3] (not ppc specific
actually).

[1]
http://www.denx.de/twiki/bin/view/PPCEmbedded/DeviceDrivers#Section_Acce
ssingPeripheralsFromUserSpace
[2] http://tinyurl.com/6c7th
[3] http://lists.linuxppc.org/linuxppc-embedded/200403/msg00059.html

CIAO,
--=20
Stephane