// wdm.h
NTSYSAPI NTSTATUS RtlIoEncodeMemIoResource(
[in] PIO_RESOURCE_DESCRIPTOR Descriptor,
[in] UCHAR Type,
[in] ULONGLONG Length,
[in] ULONGLONG Alignment,
[in] ULONGLONG MinimumAddress,
[in] ULONGLONG MaximumAddress
);
View the official Windows Driver Kit DDI referenceNo description available.
The RtlIoEncodeMemIoResource routine updates an IO_RESOURCE_DESCRIPTOR structure to describe a range of memory or I/O port addresses.
Descriptor [in]A pointer to the IO_RESOURCE_DESCRIPTOR structure to update.
Type [in]The resource type of the address range. This parameter can be CmResourceTypeMemory, CmResourceTypeMemoryLarge, or CmResourceTypePort.
Length [in]The length, in bytes, of the range of assignable addresses.
Alignment [in]The alignment, in bytes, of the starting address of address range.
MinimumAddress [in]The minimum address that can be assigned to the device.
MaximumAddress [in]The maximum address that can be assigned to the device.
RtlIoEncodeMemIoResource returns an NTSTATUS value. This routine might return one of the following values:
| Return code | Description |
|---|---|
| STATUS_SUCCESS | The IO_RESOURCE_DESCRIPTOR structure was updated. |
| STATUS_UNSUCCESSFUL | The specified value for Length or Alignment could not be encoded in an IO_RESOURCE_DESCRIPTOR structure. |
| STATUS_INVALID_PARAMETER | One or more of the specified parameters were invalid. |
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. |