NdisMMapIoSpace function (ndis.h)

Article
04/18/2022

NdisMMapIoSpace maps a given bus-relative "physical" range of device RAM or registers onto a system-space virtual range.

Syntax

NDIS_STATUS NdisMMapIoSpace(
  [out] PVOID                 *VirtualAddress,
  [in]  NDIS_HANDLE           MiniportAdapterHandle,
  [in]  NDIS_PHYSICAL_ADDRESS PhysicalAddress,
  [in]  UINT                  Length
);

Parameters

[out] VirtualAddress

Pointer to a caller-supplied variable that is set to the converted virtual address if the call is successful.

[in] MiniportAdapterHandle

Specifies the handle input to MiniportInitializeEx.

[in] PhysicalAddress

Specifies the bus-relative base physical address of the device memory range to be mapped.

[in] Length

Specifies the number of bytes to be mapped.

Return value

NdisMMapIoSpace can return any of the following status values:

Return code	Description
NDIS_STATUS_SUCCESS	The device memory range was mapped successfully so the value at VirtualAddress is valid and the mapped range has been claimed in the registry for the NIC.
NDIS_STATUS_RESOURCE_CONFLICT	An attempt to claim the device memory range in the registry has failed, possibly because another driver has already claimed the range for its device. NdisMMapIoSpace logs an error if this occurs.
NDIS_STATUS_RESOURCES	The memory could not be mapped or sufficient virtual memory could not be allocated.
NDIS_STATUS_FAILURE	Either the bus type or bus number is out of range or the given PhysicalAddress and Length were invalid (possibly not within the I/O space of the current platform).

Remarks

This function is called by drivers of NICs that have on-board memory or a bank of device registers appearing in the I/O space of the host. For example, the driver of a NIC that uses PIO calls NdisMMapIoSpace.

A successful call to NdisMMapIoSpace claims hardware resources in the registry for the driver's NIC. Consequently, only MiniportInitializeEx functions call NdisMMapIoSpace.

NdisMMapIoSpace sets the variable at VirtualAddress to NULL if it does not return NDIS_STATUS_SUCCESS.

MiniportInitializeEx either gets the PhysicalAddress value from the driver's Parameters registry key or by calling a bus-type-specific NdisXxx configuration function. The given physical address range must fall within the I/O space of the current platform. It is a programming error to call NdisMMapIoSpace with a host physical memory address.

A miniport driver must call the reciprocal NdisMUnmapIoSpace to release its claim on system resources if MiniportInitializeEx subsequently fails to initialize a NIC, if a NIC is removed from the machine, and/or when the driver is unloading.

Requirements

Requirement	Value
Minimum supported client	Supported for NDIS 6.0 and NDIS 5.1 drivers (see NdisMMapIoSpace (NDIS 5.1)) in Windows Vista. Supported for NDIS 5.1 drivers (see NdisMMapIoSpace (NDIS 5.1)) in Windows XP.
Target Platform	Universal
Header	ndis.h (include Ndis.h)
Library	Ndis.lib
IRQL	PASSIVE_LEVEL
DDI compliance rules	Irql_Miniport_Driver_Function(ndis), NdisMMapIoSpace(ndis)