Can't access ACPI memory through /dev/mem

Can't access ACPI memory through /dev/mem

[Ph. Marek]

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

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

[Len Brown]

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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> 

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

[Ph. Marek]

> 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