[coreboot] P state generator for powernow

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Mon Dec 29 02:02:42 CET 2008

On 28.12.2008 09:29, Rudolf Marek wrote:
> Carl-Daniel Hailfinger wrote:
>> Hi Rudolf,
>> On 25.12.2008 22:08, Rudolf Marek wrote:
>>> Hello,
>>> I just fixed the generator. Now It generates right P-state tables for
>>> revF of k8 CPUs. I just implemented correct TDP estimations.
>> The generator didn't compile until I added a cpuid() function.
> Yes the cpuid.c was included in March ;) Sorry I forgot to add that.

No problem.

>>> The program generates a ACPI ASL code which can be include in DSDT. It
>>> provides p-state info for powernow-k8 driver and windows driver.
>> I have attached the result of your code and what the proprietary BIOS
>> does and the fixed^Whacked-up genpowernow.c file.
>> The 1600 MHz step seems to be missing completely with the proprietary
>> BIOS. A few other differences exist as well. I'm not sure whether the
>> proprietary BIOS is right.
> The differences are in PLL lock times etc. Check the the BKDG for
> details of that field. I think I used recommended.
> Now we must investigate if the algorithm is correct. Please check the
> function and algorithm described in BKDG.
> But I'm quite happy with the result, the power estimation works ;) and
> we have
> same start/stop FID/VID ;)

The results definitely look correct. My factory BIOS seems to have
incorrect values there.

I was unable to test this, though, because the AMD DBM690T target
already has code to autogenerate the SSDT which conflicts with manual
insertion of the results of genpowernow.c.



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