LWN: Comments on "Writing a WMI driver - an introduction"

Writing a WMI driver - an introduction

gluth — Tue, 24 Jan 2012 12:34:47 +0000

Right I'm not subscribed to LWN, and do not have unread comments notification, and I thought that it is a little bit lame to paste your own blog link in comment.

I hope it was helpful for you.

Writing a WMI driver - an introduction

iksaif — Sat, 21 Jan 2012 11:23:35 +0000

Answer to myself:
- http://glucik.blogspot.com/2011/12/mof-decompilation.html
- http://msdn.microsoft.com/en-us/library/windows/hardware/...(v=vs.85).aspx

Writing a WMI driver - an introduction

iksaif — Fri, 20 Jan 2012 17:04:44 +0000

How did you generate this file exactly ? I'd like to know more about it.

Writing a WMI driver - an introduction

gluth — Sat, 17 Dec 2011 23:58:19 +0000

Thanks for a very good article! I have decompiled MOF object from this article DSDT and it is available to download here:

http://dl.dropbox.com/u/4268973/asus.h

It is fun to compare it with article author findings. It gives also a peek how informative this field of DSDT is.

Writing a WMI driver - an introduction

cathectic — Thu, 10 Jun 2010 21:46:36 +0000

Basically, yes. Unless you can get your hands on the relevant MOF, which is a good step in the right direction in at least spelling out what the methods are for, even if it doesn't tell you the right arguments to pass (for newer Acer laptops, it was dug out of the Windows binaries using 'string').

One way I've used in the past was to use the Windows Kernel Debugger to trace ACPI and replicate the function calls.

In some cases, you can also guess based on the naming conventions used in the DSDT, and/ or seeing how arguments are handled when the are passed in.

Writing a WMI driver - an introduction

iksaif — Thu, 10 Jun 2010 12:25:07 +0000

Yep, it is if you don't have any kind of documentation.
But the flags can help you (ACPI_WMI_METHOD, ACPI_WMI_EVENT).

A debug option was added to wmi.ko last month, the module will dump wmi informations on load, and it uses wmidump output format. So you don't have to search _WDG in your DSDT.

But even when you have found the correct UUID, you'll need to find/guess events code and methods id ...

Writing a WMI driver - an introduction

hadess — Thu, 10 Jun 2010 10:25:35 +0000

How does one tie the UUIDs of the different objects in the DSDT to what they're supposed to do? Is it a load of guesswork?

Writing a WMI driver - an introduction

evgeny — Thu, 10 Jun 2010 07:48:04 +0000

> On Linux, it can be found in /sys/firmware/acpi/DSDT

Here (2.6.30), it's in /sys/firmware/acpi/tables/DSDT