Re: Intel Core2Duo mobile - how does the VID get set?

[Brian Morrison <bdm@fenrir.org.uk>]

Pallipadi, Venkatesh wrote:

>> After a fair bit of Googling and reading around, I'm none the wiser 
>> about exactly how Linux 2.6.x sets the processor VID (or for 
>> that matter 
>> how it decides the FID settings) when using the ondemand governor and 
>> cpufreq stuff.
>>
>> Can anyone tell me a) whether this is obtained from the BIOS, 
>> something 
>> in the MSR of the processor or elsewhere and
> 
> Yes. The freq and voltage supported comes from the platform BIOS. BIOS
> exports this in an ACPI table which is handled by acpi-cpufreq driver in
> Linux kernel.
> 

OK, thanks for that.

>  
>> b) whether there is an 
>> interface in /proc or /sys where one can find out what is set 
>> and modify it?
> 
> There is no way of modifying and using new VIDs etc in Linux kernel
> (other than exporting your own DSDT and hacking the related code).

Is there a way of viewing the ACPI table contents relating to the VIDs
and FIDs?

-- 

Brian Morrison

bdm@fenrir.org.uk