RE: Walking all the physical memory in an x86 system

[linux-os]

On Tue, 30 Nov 2004, Hanson, Jonathan M wrote:

> -----Original Message-----
> From: linux-kernel-owner@xxxxxxxxxxxxxxx
> [mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of Jan Engelhardt
> Sent: Tuesday, November 30, 2004 9:10 AM
> To: Hanson, Jonathan M
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Subject: RE: Walking all the physical memory in an x86 system
>
> > > dd_rescue /dev/mem copyofmem
> >
> > I'm not sure what dd_rescue is as I've never heard of
> > it. However, I don't think such an operation can be done from userspace
> > because I need the physical addresses of memory not the virtual ones.
>
> /dev/mem *is* physical.
>
> [Jon M. Hanson] I can read /dev/mem from a userspace application as root
> with no problems and print out what it sees. However, things are not so
> simple from a kernel module as I just can't call open() and read() on
> /dev/mem because no such functions are exported from the kernel. Is
> there a way to read the contents of /dev/mem from a kernel module?

You just read it directly (hint ioremap) ......


Cheers,
Dick Johnson
Penguin : Linux version 2.6.9 on an i686 machine (5537.79 BogoMips).
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