I'm trying to access a function supported by ACPI BIOS that uses ACPI
method calls to retrieve data. I have not found any good sample code in the
Microsoft DDK libraries to show how is done.
The ACPISIM example in the DDK library has a ALS code with PnP ID that
has to be compiled an put into the ACPI BIOS firmware. This PnP ID would
then cause a support device driver to be loaded and control the operation region
of the device. The loaded driver can send ACPI method calls to the
acpi.sys driver. The loaded driver receives a Pdo (Physical device Object) address
from acpi driver when it is loaded. This Pdo is required for method calls to acpi.sys.
In my case I want to use a method (_LID) call which is supported on my XP Test
notebook. This method call returns the lid status of the notebook. There isn't a
device driver supporting the operation region. The region is supported by the OS
I have found no way to attach a driver to acpi stack without having PnP ID in the
ACPI BIOS in order to acquire a acpi.sys Pdo address. or a means
to acquire the needed acpi.sys Pdo in order to send method calls as outlined in
Microsoft documentation on ACPIDriver Vista.http://www.microsoft.com/whdc/system/pnppwr/powermgmt/ACPIDriver_Vista.mspx
Is there any sample code around or good documentation on how to acquire a
Pdo when the ACPI BIOS device is supported directly by acpi.sys driver.