NdisImmediateReadPortUchar

VOID
   NdisImmediateReadPortUchar(
       IN NDIS_HANDLE WrapperConfigurationContext,
       IN ULONG Port,
       OUT PUCHAR Data
       );

NdisImmediateReadPortUchar reads a byte from a given bus-relative I/O port.

Parameters

WrapperConfigurationContext

Specifies the handle input to MiniportInitialize.

Port

Specifies the bus-relative I/O port address.

Data

Points to a caller-supplied variable in which this function returns the value read from the I/O port.

Comments

NdisImmediateReadPortUchar determines how the host accesses the given I/O port, maps the bus-relative port address, and then reads a byte from the device.

A miniport driver can call NdisImmediateReadPortUchar during initialization to read data from a device I/O port when that driver has not yet called NdisMRegisterIoPortRange to obtain mapped device memory ranges. After its call to NdisMRegisterIoPortRange, the driver uses the faster NdisRawXxx functions to communicate with its NIC.

Callers of NdisImmediateReadPortUchar run at IRQL PASSIVE_LEVEL.

See Also

MiniportInitialize, NdisImmediateReadPortUlong, NdisImmediateReadPortUshort, NdisImmediateWritePortUchar, NdisMRegisterIoPortRange, NdisRawReadPortUchar