Questions about resources

NTDEV
1

Hi all,

I am using boards with atom/poulsbo with wes (xpe) and I am searching a counter not influenced by speedstep and thermal trips.

I found it in the poulsbo hpet: it is disabled but I need some clarifications (I am new to driver development).

I can see a “high precision event timer” in device manager, it has no driver loaded but the correct memory range assigned. Who is using hpet?.

With DeviceTree I see a pdo without a fdo: can I install my fdo and use hpet resources?

I have seen the same situation with “Motherboard resources”: resources assigned + no driver loaded + pdo only, but devids.txt tells that those resources are reserved (by bios, I believe); what about hpet? Is it the same situation of motherboard res.?

Poulsbo has some registers to generate an irq for each of his three hpet timers, why “high precision event timer” has none of this interrupts?

Can I:

  1. get a free vector and irq from the o.s.
  2. use kmdf to install an isr
  3. program pulsbo to generate the assigned irq

Thank you

2

> I can see a “high precision event timer” in device manager, it has no driver loaded but the correct

memory range assigned. Who is using hpet?.

HAL itself uses it to implement things like KeStallExecutionProcessor.

–
Maxim S. Shatskih
Windows DDK MVP
xxxxx@storagecraft.com
http://www.storagecraft.com

3

“Maxim S. Shatskih” wrote in message
news:xxxxx@ntdev…
>> I can see a “high precision event timer” in device manager, it has no
>> driver loaded but the correct
>>memory range assigned. Who is using hpet?.
>
> HAL itself uses it to implement things like KeStallExecutionProcessor.

But not in XP, right? otherwise the power state of the hpet won’t be D3?

– pa

4

>> HAL itself uses it to implement things like KeStallExecutionProcessor.

But not in XP, right? otherwise the power state of the hpet won’t be D3?

On 2008.

–
Maxim S. Shatskih
Windows DDK MVP
xxxxx@storagecraft.com
http://www.storagecraft.com

5

Thank you for your answers, but what is the general rule?

As an example, usually I don’t install audio drivers, so I find the same situation, that is, a pdo without an fdo. How can I distinguish these two different cases? Can I find something like devids.txt to get some explanation?

Moreover, I have another board with atom/poulsbo in which the hpet is not present. I think that in this board the hal will use other resources, so, what about my other questions on interrupts?