using WMI to read SMBIOS in Kernel Mode

read SMBIOS data from kermel.txt

copy from http://www.databaseforum.info/15/18/760a1fec0efb9bc0.html

Drivers >> Attn: Eliyas Yakub [MSFT] Re: SMBIOS info from kernel mode

Eliyas,

Thanks for your previous post on the subject. I was able
to successfully read the Raw SMBIOS data with minor
modifications. This data matches the data returned by
wbemtest for RawSMBiosTable instance as seen in the MOF
editor for the instance.

However, I have run into difficulties on two fronts and I
hope you can give me some pointers.

1) The data is embedded in the WNODE_ALL_DATA structure.
However, the data offset returned
(PWNODE_ALL_DATA) dataBuffer->DataBlockOffset does not
seem to match the real data offset when compared to the
wbemdata. Any pointers on how to interpret the
WNODE_ALL_DATA correctly.

2) Also, I am trying to interpret the data returned to
extract manufacturer/model information. However, the raw
data does not seem to have the signatures I need to
find "_SM_", "_DMI_" and the like. Is this data structure
exactly identical to that stored in the SMBIOS according
to the standard or does WMI restructres the way it is
stored. Do you have any pointers on how to interpret the
data in either case.

Would appreciate a reply from you or anyone else who has
any ideas.

Thanks
Dibyendu Nandy


------Original Posting follows------

Subject: Re: SMBIOS info from kernel mode
From: "Eliyas Yakub [MSFT]"

AM




You can use IoWMI APIs to get SMBIOS info in kernel-mode.
It's not very
hard. Here is a small code snippet that shows how to get a
WMI data block in
kernel-mode. It is much easier than mucking with COM in
usermode.



NTSTATUS status;
GUID smbiosGUID = SMBIOS_DATA_GUID; //
defined in wmiguid.h
PVOID wmiObject = NULL;
PWNODE_ALL_DATA dataBuffer;

//
// Get a WMI block handle to the SMBIOS_DATA_GUID
//
status = IoWMIOpenBlock( (GUID *) &smbiosGUID,
WMIGUID_QUERY,
&wmiObject );
if (!NT_SUCCESS(status)) {

return status;

}

//
// Determine how much space is required for the data
//
status = IoWMIQueryAllData( wmiObject, &bufferSize,
NULL );
if (status != STATUS_BUFFER_TOO_SMALL) {

ObDereferenceObject( wmiObject );
return status;

}

//
// Allocate the necessary storage. This space must
come out of NP-pool
//
dataBuffer = ExAllocatePoolWithTag(
NonPagedPool,
bufferSize,
TAG_SMBIOS
);
if (dataBuffer == NULL) {

ObDereferenceObject( wmiObject );
return STATUS_INSUFFICIENT_RESOURCES;

}

-- 
-Eliyas
This posting is provided "AS IS" with no warranties, and
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