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+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright 2019 Cesnet
+    Copyright 2019 Netcope Technologies
+
+NFB poll mode driver library
+=================================
+
+The NFB poll mode driver library implements support for the Netcope
+FPGA Boards (**NFB-40G2, NFB-100G2, NFB-200G2QL**) and Silicom **FB2CGG3** card,
+FPGA-based programmable NICs. The NFB PMD uses interface provided by the libnfb
+library to communicate with these cards over the nfb layer.
+
+More information about the
+`NFB cards <http://www.netcope.com/en/products/fpga-boards>`_
+and used technology
+(`Netcope Development Kit <http://www.netcope.com/en/products/fpga-development-kit>`_)
+can be found on the `Netcope Technologies website <http://www.netcope.com/>`_.
+
+.. note::
+
+   This driver has external dependencies.
+   Therefore it is disabled in default configuration files.
+   It can be enabled by setting ``CONFIG_RTE_LIBRTE_NFB_PMD=y``
+   and recompiling.
+
+.. note::
+
+   Currently the driver is supported only on x86_64 architectures.
+   Only x86_64 versions of the external libraries are provided.
+
+Prerequisites
+-------------
+
+This PMD requires kernel modules which are responsible for initialization and
+allocation of resources needed for nfb layer function.
+Communication between PMD and kernel modules is mediated by libnfb library.
+These kernel modules and library are not part of DPDK and must be installed
+separately:
+
+*  **libnfb library**
+
+   The library provides API for initialization of nfb transfers, receiving and
+   transmitting data segments.
+
+*  **Kernel modules**
+
+   * nfb
+
+   Kernel modules manage initialization of hardware, allocation and
+   sharing of resources for user space applications.
+
+Dependencies can be found here:
+`Netcope common <https://www.netcope.com/en/company/community-support/dpdk-libsze2#NFB>`_.
+
+Versions of the packages
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+The minimum version of the provided packages:
+
+* for DPDK from 19.05
+
+Configuration
+-------------
+
+These configuration options can be modified before compilation in the
+``.config`` file:
+
+*  ``CONFIG_RTE_LIBRTE_NFB_PMD`` default value: **n**
+
+   Value **y** enables compilation of nfb PMD.
+
+
+Timestamps
+
+The PMD supports hardware timestamps of frame receipt on physical network interface. In order to use
+the timestamps, the hardware timestamping unit must be enabled (follow the documentation of the NFB
+products) and the device argument `timestamp=1` must be used.
+
+.. code-block:: console
+
+    $RTE_TARGET/app/testpmd -w b3:00.0,timestamp=1 <other EAL params> -- <testpmd params>
+
+When the timestamps are enabled with the *devarg*, a timestamp validity flag is set in the MBUFs
+containing received frames and timestamp is inserted into the `rte_mbuf` struct.
+
+The timestamp is an `uint64_t` field. Its lower 32 bits represent *seconds* portion of the timestamp
+(number of seconds elapsed since 1.1.1970 00:00:00 UTC) and its higher 32 bits represent
+*nanosecond* portion of the timestamp (number of nanoseconds elapsed since the beginning of the
+second in the *seconds* portion.
+
+
+Using the NFB PMD
+----------------------
+
+Kernel modules have to be loaded before running the DPDK application.
+
+NFB card architecture
+---------------------
+
+The NFB cards are multi-port multi-queue cards, where (generally) data from any
+Ethernet port may be sent to any queue.
+They are represented in DPDK as a single port.
+
+NFB-200G2QL card employs an add-on cable which allows to connect it to two
+physical PCI-E slots at the same time (see the diagram below).
+This is done to allow 200 Gbps of traffic to be transferred through the PCI-E
+bus (note that a single PCI-E 3.0 x16 slot provides only 125 Gbps theoretical
+throughput).
+
+Although each slot may be connected to a different CPU and therefore to a different
+NUMA node, the card is represented as a single port in DPDK. To work with data
+from the individual queues on the right NUMA node, connection of NUMA nodes on
+first and last queue (each NUMA node has half of the queues) need to be checked.
+
+.. figure:: img/szedata2_nfb200g_architecture.*
+    :align: center
+
+    NFB-200G2QL high-level diagram
+
+Limitations
+-----------
+
+Driver is usable only on Linux architecture, namely on CentOS.
+
+Since a card is always represented as a single port, but can be connected to two
+NUMA nodes, there is need for manual check where master/slave is connected.
+
+Example of usage
+----------------
+
+Read packets from 0. and 1. receive queue and write them to 0. and 1.
+transmit queue:
+
+.. code-block:: console
+
+   $RTE_TARGET/app/testpmd -l 0-3 -n 2 \
+   -- --port-topology=chained --rxq=2 --txq=2 --nb-cores=2 -i -a
+
+Example output:
+
+.. code-block:: console
+
+   [...]
+   EAL: PCI device 0000:06:00.0 on NUMA socket -1
+   EAL:   probe driver: 1b26:c1c1 net_nfb
+   PMD: Initializing NFB device (0000:06:00.0)
+   PMD: Available DMA queues RX: 8 TX: 8
+   PMD: NFB device (0000:06:00.0) successfully initialized
+   Interactive-mode selected
+   Auto-start selected
+   Configuring Port 0 (socket 0)
+   Port 0: 00:11:17:00:00:00
+   Checking link statuses...
+   Port 0 Link Up - speed 10000 Mbps - full-duplex
+   Done
+   Start automatic packet forwarding
+     io packet forwarding - CRC stripping disabled - packets/burst=32
+     nb forwarding cores=2 - nb forwarding ports=1
+     RX queues=2 - RX desc=128 - RX free threshold=0
+     RX threshold registers: pthresh=0 hthresh=0 wthresh=0
+     TX queues=2 - TX desc=512 - TX free threshold=0
+     TX threshold registers: pthresh=0 hthresh=0 wthresh=0
+     TX RS bit threshold=0 - TXQ flags=0x0
+   testpmd>