acpi_wmi dependency on acpi_ec

Michael Gmelin freebsdusb at
Wed Sep 2 00:20:51 UTC 2009

Andriy Gapon wrote:
> on 31/08/2009 21:57 Nate Lawson said the following:
>> Andriy Gapon wrote:
>>> Does acpi_wmi have to depend on acpi_ec so strongly as it does now?
>>> The reason I am asking is that I have a desktop system that seems to
>>> provide "something WMI", but doesn't have an EC:
>> WMI is two things:
>> 1. proprietary API to some data already available in ACPI
>> 2. standard for organizing system information not yet listed in the ACPI
>> spec
> Nate,
> thank you - I am getting some knowledge on WMI (WMI+ACPI specifically), but it is
> quite a big subject.
>>> I am not sure how to proceed next and if I can actually get anything
>>> useful with WMI on this system.
>>> For now I extracted binary MOF file stored in WQBA and used wmimofck
>>> utility (from Windows Driver Kit) on it. The following is the resulting
>>> header file:
>>> Any advice on what I could try next?
>> What you can do with it is totally dependent on the system. Sometimes it
>> offers a lot of info, sometimes not. With laptops, I think most
>> manufacturers ignored WMI and ACPI and wrote their own hotkey drivers.
> In this case I determined that ASL provides WMI interface for AMD OverDrive.
> In ASL I see code that accesses clock generator via i2c and similar.
> I think that with enough time and motivation I could figure out how to use that
> interface (from looking at the header file and ASL code for WMI methods).
> But right now I am lacking both.

Hi Andriy,

the reason I wrote the acpi_wmi driver in the first place was to make
acpi_hp possible, which seems to be the only way to access certain
functionalities (especially BIOS and wireless [wlan/wwan/bluetooth]) on
HP notebooks. Unfortunately I cannot tell what your notebook could offer
through that (as Nate pointed out - pretty horrible) interface,
depending on your modell the manufacturer might provide some information
(like HP does, see links in acpi_hp.c). Without any documentation the
wq.h file is more or less useless (what manufacturer/model are we
talking about?)

To answer your original question: Afaik, to make it work with HP
notebooks the dependency to acpi_ec cannot be avoided, but there might
be a better way to figure out if it is necessary or not?!? Certain
notebooks (like Acer models) seem to work similar to HP machines, but
without actually getting my hands on the hardware there is very little I
can provide.

I would also be interested in any documentation that provides more
details about ACPI-WMI in general, I put links to anything I could find
online into the drivers, but I still feel like this information is


More information about the freebsd-acpi mailing list