2004-03-12 09:19:00

by Ph. Marek

Subject: Can't access ACPI memory through /dev/mem

Hello everybody!

My machine gives me for
$ cat /proc/iomem
00000000-0009fbff : System RAM
0009fc00-0009ffff : reserved
000a0000-000bffff : Video RAM area
000c0000-000c7fff : Video ROM
000d0000-000d9fff : Extension ROM
000f0000-000fffff : System ROM
00100000-0f7dffff : System RAM
00100000-0022ca51 : Kernel code
0022ca52-0029d8e3 : Kernel data
0f7e0000-0f7e7fff : ACPI Tables
0f7e8000-0f7fffff : ACPI Non-volatile Storage
80100000-801fffff : PCI Bus #01
80100000-8011ffff : Silicon Integrated Systems [SiS] SiS630 GUI
and so on.

Now I can access the whole area below the ACPI tables (I tried RAM, video and
system ROM, and kernel code/data).
But on reaching the ACPI tables and above (PCI space and so on) I get no data
(that is, vche blanks the screen).

I'd expect that for the PCI space - as this is really IO-memory and shouldn't
be messed with.

But I'd like to access the ACPI tables; especially the NVRAM, as some machines
store DMI data there.

This is on
Linux version 2.4.24-1-686 (herbert@gondolin) (gcc version 3.3.2 (Debian))
and an old 2.4.19 kernel.


Any tips? Help for accessing this memory space?


Regards,

Phil

2004-03-12 15:55:25

by Brown, Len

Subject: Re: Can't access ACPI memory through /dev/mem

does dmidecode find what you're looking for?

http://www.nongnu.org/dmidecode/

-Len

On Fri, 2004-03-12 at 04:18, Ph. Marek wrote:
> Hello everybody!
>
> My machine gives me for
> $ cat /proc/iomem
> 00000000-0009fbff : System RAM
> 0009fc00-0009ffff : reserved
> 000a0000-000bffff : Video RAM area
> 000c0000-000c7fff : Video ROM
> 000d0000-000d9fff : Extension ROM
> 000f0000-000fffff : System ROM
> 00100000-0f7dffff : System RAM
> 00100000-0022ca51 : Kernel code
> 0022ca52-0029d8e3 : Kernel data
> 0f7e0000-0f7e7fff : ACPI Tables
> 0f7e8000-0f7fffff : ACPI Non-volatile Storage
> 80100000-801fffff : PCI Bus #01
> 80100000-8011ffff : Silicon Integrated Systems [SiS] SiS630
> GUI
> and so on.
>
> Now I can access the whole area below the ACPI tables (I tried RAM,
> video and
> system ROM, and kernel code/data).
> But on reaching the ACPI tables and above (PCI space and so on) I get
> no data
> (that is, vche blanks the screen).
>
> I'd expect that for the PCI space - as this is really IO-memory and
> shouldn't
> be messed with.
>
> But I'd like to access the ACPI tables; especially the NVRAM, as some
> machines
> store DMI data there.
>
> This is on
> Linux version 2.4.24-1-686 (herbert@gondolin) (gcc version
> 3.3.2 (Debian))
> and an old 2.4.19 kernel.
>
>
> Any tips? Help for accessing this memory space?
>
>
> Regards,
>
> Phil
> -
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>

2004-03-15 12:59:27

by Ph. Marek

Subject: Re: Can't access ACPI memory through /dev/mem

> does dmidecode find what you're looking for?
>
> http://www.nongnu.org/dmidecode/
That may solve parts of my problem - ie., the reading of dmi data.

But my question remains ... why can't I read this adresses??


Regards,

Phil