Edit

Share via

RtlCmEncodeMemIoResource function (wdm.h)

  • Article

The RtlCmEncodeMemIoResource routine updates a CM_PARTIAL_RESOURCE_DESCRIPTOR structure to describe a range of memory or I/O port addresses.

Syntax

NTSYSAPI NTSTATUS RtlCmEncodeMemIoResource(
  [in] PCM_PARTIAL_RESOURCE_DESCRIPTOR Descriptor,
  [in] UCHAR                           Type,
  [in] ULONGLONG                       Length,
  [in] ULONGLONG                       Start
);

Parameters

[in] Descriptor

A pointer to the CM_PARTIAL_RESOURCE_DESCRIPTOR structure to update.

[in] Type

The resource type of the memory. This parameter can be CmResourceTypeMemory, CmResourceTypeMemoryLarge, or CmResourceTypePort.

[in] Length

The length, in bytes, of the range of allocated addresses.

[in] Start

The starting address of the range of memory or I/O port addresses.

Return value

RtlCmEncodeMemIoResource returns an NTSTATUS value. This routine might return one of the following values:

Return code Description
STATUS_SUCCESS
 The CM_PARTIAL_RESOURCE_DESCRIPTOR structure has been updated.
STATUS_UNSUCCESSFUL
 The specified value for Length cannot be encoded in a CM_PARTIAL_RESOURCE_DESCRIPTOR structure.
STATUS_INVALID_PARAMETER
 One or more of the specified parameters are invalid.

Remarks

Addresses that are larger than 32 bits in length must satisfy certain alignment restrictions or else the routine returns STATUS_UNSUCCESSFUL.

Address length Alignment restriction
40 bits Lowest 8 bits must be zero.
48 bits Lowest 16 bits must be zero.
64 bits Lowest 32 bits must be zero.

Requirements

Requirement Value
Minimum supported client Available in Windows Vista and later versions of Windows.
Target Platform Universal
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL Any level

See also

CM_PARTIAL_RESOURCE_DESCRIPTOR

RtlCmDecodeMemIoResource