USB Audio 2.0 Drivers - Windows drivers
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Network Interface Card Support – Windows drivers

This matter describes the forms of Community Interface Playing cards (NICs) that an NDIS miniport driver can handle, in addition to how the totally different sorts of NICs have an effect on the best way a driver transfers community information.

Reporting a NIC’s medium kind to NDIS

To report a medium kind for a NIC, a miniport driver passes a pointer to an NDIS_MINIPORT_ADAPTER_GENERAL_ATTRIBUTES construction within the MiniportAttributes parameter of the NdisMSetMiniportAttributes perform. A miniport driver calls NdisMSetMiniportAttributes from its MiniportInitializeEx perform throughout initialization. Miniport drivers ought to set the MiniportAttributes attributes after setting the registration attributes within the NDIS_MINIPORT_ADAPTER_REGISTRATION_ATTRIBUTES construction and earlier than setting another attributes. Setting the MiniportAttributes attributes is obligatory. The driving force units the MediaType member of the NDIS_MINIPORT_ADAPTER_GENERAL_ATTRIBUTES construction to the suitable media kind when setting the MiniportAttributes attributes.

When an overlying NDIS protocol driver calls NdisOpenAdapterEx to bind to a specified miniport adapter, it gives a listing of medium sorts on which it may function. NDIS makes use of the data from the miniport driver and from the protocol driver to arrange a binding. This binding gives the trail for transferring community information up and down the motive force stack.

Bodily NICs

The steps {that a} miniport driver completes to initialize a miniport adapter and to ship and obtain community information can depend upon the options of a bodily system, as follows.

  • NDIS-WDM NICs

    With NDIS-WDM NICs, comparable to USB-based NICs, the best way the miniport driver manages reminiscence with DMA doesn’t matter to NDIS and isn’t seen to it.

  • Bus-master DMA NICs

    These NICs can instantly entry host reminiscence by an on-board DMA controller that manages the switch of information between the community and host reminiscence with out utilizing the host CPU.

    To ship, the miniport driver units up the NIC to map the outgoing buffers. The miniport driver then causes the system to begin its switch from this reminiscence. The NIC DMA controller transfers the info from shared system reminiscence onto the community and interrupts the CPU when the ship is full. To obtain, the DMA controller transfers incoming information to host reminiscence earlier than notifying the host with an interrupt.

    A bus-master DMA NIC sometimes has an onboard ring buffer that the miniport driver maps to a set of buffers in system reminiscence. Sometimes, the NIC might be programmed to effectively deal with a number of packets. A miniport driver that manages such a NIC sometimes helps multipacket sends and receives as a result of the NIC can effectively deal with a number of packets and thereby enhance its I/O throughput.

  • Nonbusmaster DMA NICs

    Presently, nonbusmaster DMA NICs embrace the next:

Digital NICs and miniports

In a digital machine, NDIS miniport drivers can handle both software-only assets as a digital miniport, or they will handle a digital NIC that represents {hardware} assets. The next desk explains the variations between a digital miniport and a digital NIC.

Attribute Digital miniport Digital NIC
Definition An NDIS miniport driver that maps to a software-enumerated PnP system. A NIC managed by the host OS hypervisor. The hypervisor makes the digital machine assume that it has some {hardware}, however no such {hardware} really exists within the bodily world.
Has interrupts No Sure
Can use DMA No Sure
Is created or destroyed by… The visitor OS The host OS
Can attain exterior of a visitor VM No Sure

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