ZwPowerInformation function (ntddk.h)

Article
02/22/2024

The ZwPowerInformation routine sets or retrieves system power information.

Syntax

NTSYSAPI NTSTATUS ZwPowerInformation(
  [in]            POWER_INFORMATION_LEVEL InformationLevel,
  [in, optional]  PVOID                   InputBuffer,
  [in]            ULONG                   InputBufferLength,
  [out, optional] PVOID                   OutputBuffer,
  [in]            ULONG                   OutputBufferLength
);

Parameters

[in] InformationLevel

Specifies the requested information level, which indicates the specific power information to be set or retrieved. Currently, the only supported POWER_INFORMATION_LEVEL value is PlatformInformation.

Value	Meaning
PlatformInformation	Information represents the currently supported power capabilities of the system. Information may change as drivers are installed. For example, the installation of legacy device drivers that do not support power management might modify the capabilities of the system.

[in, optional] InputBuffer

Pointer to a caller-allocated input buffer. This parameter must be NULL, otherwise ERROR_INVALID_PARAMETER is returned.

[in] InputBufferLength

Size, in bytes, of the buffer at InputBuffer. The parameter must be set to zero.

[out, optional] OutputBuffer

A pointer to an output buffer. The data type of this buffer depends on the information level requested in the InformationLevel parameter. For the PlatformInformation level, the only currently supported value, the OutputBuffer parameter is required and should be of the POWER_PLATFORM_INFORMATION type.

[in] OutputBufferLength

Size, in bytes, of the output buffer. Depending on the information level requested, the buffer may be variably sized. PlatformInformation, the only currently supported value, requires a buffer that is the size of a POWER_PLATFORM_INFORMATION structure.

Return value

Returns STATUS_SUCCESS if the call is successful. If the call fails, possible error codes include the following:

Return code	Description
STATUS_BUFFER_TOO_SMALL	The output buffer is of insufficient size to contain the data being returned.
STATUS_INVALID_PARAMETER	The PlatformInformation information level, which is the only currently supported value, requires no input buffer and must contain an output buffer. The caller either supplied an input buffer or no output buffer.
STATUS_ACCESS_DENIED	The caller had insufficient access rights to perform the requested action.

Remarks

NtPowerInformation and ZwPowerInformation are two versions of the same Windows Native System Services routine.

For calls from kernel-mode drivers, the NtXxx and ZwXxx versions of a Windows Native System Services routine can behave differently in the way that they handle and interpret input parameters. For more information about the relationship between the NtXxx and ZwXxx versions of a routine, see Using Nt and Zw Versions of the Native System Services Routines.

Examples

This example illustrates a valid function call.

POWER_PLATFORM_INFORMATION PlatformInfo = {0};
NTSTATUS Result = NtPowerInformation(PlatformInformation, NULL, 0, &PlatformInfo, sizeof(PlatformInfo));

Requirements

Requirement	Value
Minimum supported client	Windows 8
Minimum supported server	Windows Server 2012
Target Platform	Universal
Header	ntddk.h (include Wdm.h, Ntddk.h, Ntpoapi.h)
Library	Ntoskrnl.lib
DLL	Ntoskrnl.lib
IRQL	PASSIVE_LEVEL
DDI compliance rules	HwStorPortProhibitedDDIs(storport), PowerIrpDDis(wdm)

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