SK(4) BSD Kernel Interfaces Manual SK(4)NAMEsk — SysKonnect SK-984x and SK-982x PCI Gigabit Ethernet adapter driver
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
The sk driver provides support for the SysKonnect SK-984x and SK-982x
series PCI Gigabit Ethernet adapters.
The SysKonnect adapters consist of two main components: the XaQti Corp.
XMAC II gigabit MAC and the SysKonnect GEnesis controller ASIC. The XMAC
provides the gigabit MAC and PHY support while the GEnesis provides an
interface to the PCI bus, DMA support, packet buffering and arbitration.
The GEnesis can control up to two XMACs simultaneously, allowing dual-
port NIC configurations.
The SK-982x 1000baseT adapters also include a Broadcom BCM5400 1000baseTX
PHY which is used in place of the XMAC's internal PHY. The Broadcom PHY
is connected to the XMAC via its GMII port.
The sk driver configures dual port SysKonnect adapters such that each
XMAC is treated as a separate logical network interface. Both ports can
operate independently of each other and can be connected to separate net‐
works. The SysKonnect driver software currently only uses the second
port on dual port adapters for failover purposes: if the link on the pri‐
mary port fails, the SysKonnect driver will automatically switch traffic
onto the second port.
Also supported is the Marvell Semiconductor 88E100* gigabit PHY.
The XaQti XMAC II supports full and half duplex operation with autonego‐
tiation. The XMAC also supports unlimited frame sizes. Support for
jumbo frames is provided via the interface MTU setting. Selecting an MTU
larger than 1500 bytes with the ifconfig(8) utility configures the
adapter to receive and transmit jumbo frames. Using jumbo frames can
greatly improve performance for certain tasks, such as file transfers and
The sk driver supports the following media types:
autoselect Enable autoselection of the media type and options.
The user can manually override the autoselected
mode by adding media options to the /etc/rc.conf
1000baseTX Set 1000baseTX operation over twisted pair. This
is only available for SK-982x series adapters with
1000baseT ports. Both full-duplex and half-duplex
modes are supported.
1000baseSX Set 1000Mbps (Gigabit Ethernet) operation. Both
full-duplex and half-duplex modes are supported.
The sk driver supports the following media options:
full-duplex Force full duplex operation
half-duplex Force half duplex operation.
For more information on configuring this device, see ifconfig(8).
Adapters supported by the sk driver include:
· 3Com 3C940 single port, 1000baseT adapter
· 3Com 3C2000-T single port, 1000baseT adapter
· Belkin F5D5005 single port, 1000baseT adapter
· D-Link DGE-530T single port, 1000baseT adapter
· Linksys (revision 2) single port, 1000baseT adapter
· SK-9521 SK-NET GE-T single port, 1000baseT adapter
· SK-9821 SK-NET GE-T single port, 1000baseT adapter
· SK-9822 SK-NET GE-T dual port, 1000baseT adapter
· SK-9841 SK-NET GE-LX single port, single mode fiber adapter
· SK-9842 SK-NET GE-LX dual port, single mode fiber adapter
· SK-9843 SK-NET GE-SX single port, multimode fiber adapter
· SK-9844 SK-NET GE-SX dual port, multimode fiber adapter
· SMC 9452TX single port, 1000baseT adapter
Tunables can be set at the loader(8) prompt before booting the kernel or
stored in loader.conf(5).
Disable jumbo frame support. Systems with less memory can set it
to a non-zero value to save memory. The default value is 0.
The following variable is available as both sysctl(8) variable and
This variable controls interrupt moderation. The accepted range
is 10 to 10000. The default value is 100 microseconds. The
interface has to be brought down and up again before a change
sk%d: couldn't map memory A fatal initialization error has occurred.
sk%d: couldn't map ports A fatal initialization error has occurred.
sk%d: couldn't map interrupt A fatal initialization error has occurred.
sk%d: no memory for softc struct! The driver failed to allocate memory
for per-device instance information during initialization.
sk%d: failed to enable memory mapping! The driver failed to initialize
PCI shared memory mapping. This might happen if the card is not in a
sk%d: no memory for jumbo buffers! The driver failed to allocate memory
for jumbo frames during initialization.
sk%d: watchdog timeout The device has stopped responding to the network,
or there is a problem with the network connection (cable).
SEE ALSOaltq(4), arp(4), miibus(4), netintro(4), ng_ether(4), vlan(4),
XaQti XMAC II datasheet, http://www.xaqti.com.
SysKonnect GEnesis programming manual, http://www.syskonnect.com.
The sk device driver first appeared in FreeBSD 3.0.
The sk driver was written by Bill Paul ⟨email@example.com⟩.
BSD November 23, 2010 BSD