IWDFDevice3::UnmapIoSpace method (wudfddi.h)

Article
02/22/2024

[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]

The UnmapIoSpace method unmaps a specified range of physical addresses previously mapped by MapIoSpace method.

Syntax

void UnmapIoSpace(
  [in] void   *PseudoBaseAddress,
  [in] SIZE_T NumberOfBytes
);

Parameters

[in] PseudoBaseAddress

Pointer to the pseudo base address obtained from a previous call to MapIoSpace method to which the physical address range was mapped.

[in] NumberOfBytes

Specifies the number of bytes that were mapped.

Return value

None

Remarks

If a driver calls MapIoSpace in OnPrepareHardware callback. It calls UnmapIoSpace in its OnReleaseHardware callback.

For an example, see Finding and Mapping Hardware Resources in a UMDF Driver.

Examples

See example code in IWDFDevice3::MapIoSpace.

Requirements

Requirement	Value
End of support	Unavailable in UMDF 2.0 and later.
Target Platform	Desktop
Minimum UMDF version	1.11
Header	wudfddi.h
DLL	WUDFx.dll

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