SUME(4)                FreeBSD Kernel Interfaces Manual                SUME(4)

NAME
     sume - NetFPGA SUME 4x10Gb Ethernet driver

SYNOPSIS
     To compile this driver into the kernel, place the following lines in your
     kernel configuration file:

           device sume

     Alternatively, to load the driver as a module at boot time, place the
     following line in loader.conf(5):

           if_sume_load="YES"

DESCRIPTION
     The sume driver provides support for NetFPGA SUME Virtex-7 FPGA
     Development Board with the reference NIC bitstream loaded onto it.  The
     HDL design for the reference NIC project uses the RIFFA based DMA engine
     to communicate with the host machine over PCIe.  Every packet is
     transmitted to / from the board via a single DMA transaction, taking up
     to two or three interrupts per one transaction which yields low
     performance.

     There is no support for Jumbo frames as the hardware is capable of
     dealing only with frames with maximum size of 1514 bytes.  The hardware
     does not support multicast filtering, provides no checksums, and offers
     no other offloading.

SEE ALSO
     arp(4), netgraph(4), netintro(4), ng_ether(4), vlan(4), ifconfig(8)

AUTHORS
     The Linux sume driver was originally written by Bjoern A. Zeeb.  The
     FreeBSD version and this manual page were written by Denis Salopek as a
     GSoC project.  More information about the project can be found here:
     https://wiki.freebsd.org/SummerOfCode2020Projects/NetFPGA_SUME_Driver

BUGS
     The reference NIC hardware design provides no mechanism for quiescing
     inbound traffic from interfaces configured as DOWN.  All packets from
     administratively disabled interfaces are transferred to main memory,
     leaving the driver with the task of dropping such packets, thus consuming
     PCI bandwidth, interrupts and CPU cycles in vain.

     Pre-built FPGA bitstream from the NetFPGA project may not work correctly.
     At higher RX packet rates, the newly incoming packets can overwrite the
     ones in an internal FIFO so the packets would arrive in main memory
     corrupted, until a physical reset of the board.

     Occasionally, the driver can get stuck in a non-IDLE TX state due to a
     missed interrupt.  The driver includes a watchdog function which monitors
     for such a condition and resets the board automatically.  For more
     details, visit the NetFPGA SUME project site.

FreeBSD 13.1-RELEASE-p6         August 30, 2020        FreeBSD 13.1-RELEASE-p6