Registering MiniportXXX Functions (Windows Embedded CE 6.0)

Article
01/05/2012

1/6/2010

Each address member of the NDIS_MINIPORT_CHARACTERISTICS structure must be initialized. To initialize, the address members must be set to the address of a miniport-supplied function or to NULL. The miniport must supply entry points for all mandatory MiniportXXX functions; otherwise, NDIS will unload the driver. The MiniportXXX functions are defined in the Ndis.h file.

Because the miniport supplies the addresses, and not the names, of its MiniportXXX functions, driver developers are free to name these functions whatever they want. A reasonable miniport-development strategy is to give these functions names that make debugging easier. For instance, the miniport NIC driver Mp.sys could name the entry points MpISR, MpSend, and so on.

Some MiniportXXX functions are optional. For instance, if a NIC does not generate interrupts, the miniport must poll its NIC. Such a miniport must have a MiniportTimer function but does not need a MiniportISR function, a MiniportEnableInterrupt function, or a MiniportDisableInterrupt function.

A typical miniport driver uses a small number of functions to communicate through NDIS with the upper layers and hardware. NDIS calls MiniportXXX functions to communicate with a miniport on its own behalf or on the behalf of a protocol driver.

NDIS NIC miniports and upper-layer drivers use the NDIS library, called Ndis.sys, to communicate with each other through calls to NdisXXX functions.

The following table shows the NDIS Driver Upper-Edge Functions, or miniport driver functions, that a miniport can export.

Function	Description	Asynchronous operation
DriverEntry	Called by the operating system to activate and initialize the miniport driver.	Not applicable
MiniportCheckForHang	Checks the internal state of the NIC.	No
MiniportDisableInterrupt	Disables the NIC from generating interrupts.	No
MiniportEnableInterrupt	Enables the NIC to generate interrupts.	No
MiniportHalt	Deallocates and deregisters resources for the NIC and halts the NIC so that it is no longer functioning.	No
MiniportHandleInterrupt	Deferred processing function called to complete interrupt-driven I/O processing.	No
MiniportInitialize	Initializes the NIC.	No
MiniportISR	Runs at a high priority as the interrupt service routine for the NIC.	No
MiniportQueryInformation	Queries the capabilities and status of the miniport driver.	Yes
MiniportReconfigure	Currently, the NDIS library never calls this function, but a MiniportInitialize function can call a MiniportReconfigure function as an internal driver function.	Not Applicable
MiniportReset	Issues a hardware reset to the NIC.	Yes
MiniportReturnPacket	Receives a packet from an upper layer that was previously passed by a call to NdisMIndicateReceivePacket.	No
MiniportSend	Transmits a packet through the NIC onto the network. Required if the driver has no MiniportSendPackets or MiniportWanSend function.	Yes
MiniportSendPackets	Transmits an array of packets through the NIC onto the network.	Yes
MiniportSetInformation	Changes information about the miniport driver or its NIC.	Yes
MiniportShutdown	Restores a NIC to its initial state when the system is shut down.	No
MiniportSynchronizeISR	Synchronizes access to resources shared with MiniportISR or MiniportDisableInterrupt.	No
MiniportTransferData	Copies the contents of a packet received by the NIC into a given packet buffer.	Yes
MiniportWanSend	Transmits a packet through the NIC onto the network. Required if the driver controls a WAN NIC.	No

Many miniport functions can operate either synchronously or asynchronously. The asynchronous functions have functions that must be called when an operation is finished, as shown in the following table. For example, if a protocol driver calls the NdisReset function to reset a NIC, the miniport's MiniportReset function can change the reset operation by returning NDIS_STATUS_PENDING. Eventually, the MiniportReset function must call the NdisMResetComplete function to indicate the final status of the reset request.

The following table shows the NDIS completion function that corresponds to each possibly asynchronous upper-edge miniport driver function.

Function	Completion function
MiniportSend,MiniportSendPackets	NdisMSendComplete
MiniportQueryInformation	NdisMQueryInformationComplete
MiniportReset	NdisMResetComplete
MiniportSetInformation	NdisMSetInformationComplete
MiniportTransferData	NdisMTransferDataComplete

Registering MiniportXXX Functions (Windows Embedded CE 6.0)

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