Equivalent of GetSystemFirmwareTable in kernel mode

NTDEV
1

Hi,

I am able to use EnumSystemFirmwareTables/GetSystemFirmwareTable to read the FW Tables from user-side.

However If I want to read the same information from the kernel mode driver, what is the equivalent DDI?

Thanks in advance

2

For what purpose?

d

debt from my phone

From: xxxxx@gmail.com
Sent: 3/15/2012 7:12 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Equivalent of GetSystemFirmwareTable in kernel mode

Hi,

I am able to use EnumSystemFirmwareTables/GetSystemFirmwareTable to read the FW Tables from user-side.

However If I want to read the same information from the kernel mode driver, what is the equivalent DDI?

Thanks in advance

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3

Hi Doron,

This is to allow the UEFI FW to pass custom information in a custom ACPI Table to be consumed by a kernel mode driver.

Regards,
Thiru

4

What data are you consuming in the driver?

d

debt from my phone

From: xxxxx@gmail.com
Sent: 3/15/2012 7:35 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Equivalent of GetSystemFirmwareTable in kernel mode

Hi Doron,

This is to allow the UEFI FW to pass custom information in a custom ACPI Table to be consumed by a kernel mode driver.

Regards,
Thiru

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5

The data is related to device calibration and configuration, which cannot be done through the DSDT.

I am looking for an equivalent mechanism of what is already available in the user-mode.

Regards,
Thiru

6

If it is exposed via acpi, can you expose it on your acpi enumerated device and send IOCTL_ACPI_XXX down the stack to retrieve the data?

d

debt from my phone

From: xxxxx@gmail.com
Sent: 3/15/2012 7:45 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Equivalent of GetSystemFirmwareTable in kernel mode

The data is related to device calibration and configuration, which cannot be done through the DSDT.

I am looking for an equivalent mechanism of what is already available in the user-mode.

Regards,
Thiru

NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer

7

Hi Doron,

Thanks for your reply.

Exposing the configuration and calibration data through ACPI Device namespace (i.e. through DSDT/SSDT) is not an option as the data is produced by the tool running in UEFI FW, where as DSDT/SSDT had to be compiled through ACPI Compiler offline.

I am able to expose this data through a custom ACPI Table and access it through the user-side APIs viz. EnumSystemFirmwareTables/GetSystemFirmwareTable.
The trouble is to find the kernel side equivalent APIs.

Regards,
Thiru

8

On 3/15/2012 10:13 PM, xxxxx@gmail.com wrote:

Hi,

I am able to use EnumSystemFirmwareTables/GetSystemFirmwareTable to read the FW Tables from user-side.

However If I want to read the same information from the kernel mode driver, what is the equivalent DDI?

Thanks in advance

See if this helps.

typedef enum _SYSTEM_INFORMATION_CLASS {
[…]
SystemFirmwareInformation = 0x4c, // W2k3SP1 and later
[…]
} SYSTEM_INFORMATION_CLASS;

// Used with SystemFirmwareInformation information class
// SystemInfoBufferSize = sizeof(SYSTEM_FIRMWARE_INFORMATION) - 1 +
FirmwareTableSize
// Table data is returned at the end of the SYSTEM_FIRMWARE_INFORMATION.
typedef struct _SYSTEM_FIRMWARE_INFORMATION {
ULONG FirmwareTableProviderSignature;
ULONG Unknown;
ULONG FirmwareTableID;
ULONG FirmwareTableSize;
UCHAR Data[1];
} SYSTEM_FIRMWARE_INFORMATION, *PSYSTEM_FIRMWARE_INFORMATION;

9

Hi George,

Thanks a lot for your reply.

It seems like I do not find SystemFirmwareInformation and SYSTEM_FIRMWARE_INFORMATION declarations in the WDK.

Since you provide these already, I could call the NtQuerySystemInformation and get back the result of what user side API EnumSystemFirmwareTables returns.

But I could not get the GetSystemFirmwareTable equivalent information. Any ideas?

Regards,
Thiru

10

On 3/16/2012 2:08 PM, xxxxx@gmail.com wrote:

Hi George,

Thanks a lot for your reply.

It seems like I do not find SystemFirmwareInformation and SYSTEM_FIRMWARE_INFORMATION declarations in the WDK.

Since you provide these already, I could call the NtQuerySystemInformation and get back the result of what user side API EnumSystemFirmwareTables returns.

But I could not get the GetSystemFirmwareTable equivalent information. Any ideas?

Regards,
Thiru

Thiru,

Why not set a couple of breakpoints and figure it out for yourself?

kd> x nt!*FirmwareTable*
fffff80002ad1b70 nt!ExpGetSystemFirmwareTableInformation = <no type>information&gt;<br>fffff8000283c9b0 nt!ExpFirmwareTableProviderListHead = information>
fffff80002ad6f40 nt!ExpRegisterFirmwareTableInformationHandler = <no>type information&gt;<br>fffff8000283c940 nt!ExpFirmwareTableResource =
fffff8000280d440 nt!WmipFirmwareTableArray = <no type information><br>fffff8000276d6e0 nt!WmipFirmwareTableHandler =

Set a breakpoint at nt!ExpGetSystemFirmwareTableInformation, then call
GetSystemFirmwareTable and look at the call stack when the breakpoint is
hit.

You may be able to access the same information using WMI.

> But I could not get the GetSystemFirmwareTable equivalent information. <

Why can’t you?

Regards,

gmg.