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     xl — 3Com Etherlink XL and Fast Etherlink XL Ethernet device driver


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

           device miibus
           device xl

     Alternatively, to load the driver as a module at boot time, place the following line in



     The xl driver provides support for PCI Ethernet adapters and embedded controllers based on
     the 3Com "boomerang," "cyclone," "hurricane" and "tornado" bus-master Etherlink XL chips.

     The Etherlink XL chips support built-in 10baseT, 10base2 and 10base5 transceivers as well as
     an MII bus for externally attached PHY transceivers.  The 3c905 series typically uses a
     National Semiconductor NS 83840A 10/100 PHY for 10/100 Mbps support in full or half-duplex.
     The 3c905B adapters have built-in autonegotiation logic mapped onto the MII for
     compatibility with previous drivers.  Fast Etherlink XL adapters such as the 3c905-TX and
     3c905B-TX are capable of 10 or 100Mbps data rates in either full or half duplex and can be
     manually configured for any supported mode or automatically negotiate the highest possible
     mode with a link partner.

     The xl driver supports the following media types:

     autoselect            Enable autoselection of the media type and options.  Note that this
                           option is only available with the 3c905 and 3c905B adapters with
                           external PHYs or built-in autonegotiation logic.  For 3c900 adapters,
                           the driver will choose the mode specified in the EEPROM.  The user can
                           change this by adding media options to the /etc/rc.conf file.

     10baseT/UTP           Set 10Mbps operation.  The mediaopt option can also be used to select
                           either full-duplex or half-duplex modes.

     100baseTX             Set 100Mbps (Fast Ethernet) operation.  The mediaopt option can also
                           be used to select either full-duplex or half-duplex modes.

     10base5/AUI           Enable AUI transceiver (available only on COMBO cards).

     10base2/BNC           Enable BNC coax transceiver (available only on COMBO cards).

     The xl driver supports the following media options:

     full-duplex           Force full duplex operation.

     half-duplex           Force half duplex operation.

     Note that the 100baseTX media type is only available if supported by the adapter.  For more
     information on configuring this device, see ifconfig(8).


     The xl driver supports the following hardware:

        3Com 3c900-TPO
        3Com 3c900-COMBO
        3Com 3c905-TX
        3Com 3c905-T4
        3Com 3c900B-TPO
        3Com 3c900B-TPC
        3Com 3c900B-FL
        3Com 3c900B-COMBO
        3Com 3c905B-T4
        3Com 3c905B-TX
        3Com 3c905B-FX
        3Com 3c905B-COMBO
        3Com 3c905C-TX
        3Com 3c980, 3c980B, and 3c980C server adapters
        3Com 3cSOHO100-TX OfficeConnect adapters
        3Com 3c450 HomeConnect adapters
        3Com 3c555, 3c556 and 3c556B mini-PCI adapters
        3Com 3C3SH573BT, 3C575TX, 3CCFE575BT, 3CXFE575BT, 3CCFE575CT, 3CXFE575CT, 3CCFEM656,
         3CCFEM656B, and 3CCFEM656C, 3CXFEM656, 3CXFEM656B, and 3CXFEM656C CardBus adapters
        3Com 3c905-TX, 3c905B-TX 3c905C-TX, 3c920B-EMB, and 3c920B-EMB-WNM embedded adapters

     Both the 3C656 family of CardBus cards and the 3C556 family of MiniPCI cards have a built-in
     proprietary modem.  Neither the xl driver nor any other FreeBSD driver supports this modem.


     xl%d: couldn't map memory  A fatal initialization error has occurred.

     xl%d: couldn't map interrupt  A fatal initialization error has occurred.

     xl%d: device timeout  The device has stopped responding to the network, or there is a
     problem with the network connection (cable).

     xl%d: no memory for rx list  The driver failed to allocate an mbuf for the receiver ring.

     xl%d: no memory for tx list  The driver failed to allocate an mbuf for the transmitter ring
     when allocating a pad buffer or collapsing an mbuf chain into a cluster.

     xl%d: command never completed!  Some commands issued to the 3c90x ASIC take time to
     complete: the driver is supposed to wait until the 'command in progress' bit in the status
     register clears before continuing.  In rare instances, this bit may not clear.  To avoid
     getting caught in an infinite wait loop, the driver only polls the bit for a finite number
     of times before giving up, at which point it issues this message.  This message may be
     printed during driver initialization on slower machines.  If you see this message but the
     driver continues to function normally, the message can probably be ignored.

     xl%d: chip is in D3 power state -- setting to D0  This message applies only to 3c905B
     adapters, which support power management.  Some operating systems place the 3c905B in low
     power mode when shutting down, and some PCI BIOSes fail to bring the chip out of this state
     before configuring it.  The 3c905B loses all of its PCI configuration in the D3 state, so if
     the BIOS does not set it back to full power mode in time, it will not be able to configure
     it correctly.  The driver tries to detect this condition and bring the adapter back to the
     D0 (full power) state, but this may not be enough to return the driver to a fully
     operational condition.  If you see this message at boot time and the driver fails to attach
     the device as a network interface, you will have to perform second warm boot to have the
     device properly configured.

     Note that this condition only occurs when warm booting from another operating system.  If
     you power down your system prior to booting FreeBSD, the card should be configured

     xl%d: WARNING: no media options bits set in the media options register!  This warning may
     appear when using the driver on some Dell Latitude docking stations with built-in 3c905-TX
     adapters.  For whatever the reason, the 'MII available' bit in the media options register on
     this particular equipment is not set, even though it should be (the 3c905-TX always uses an
     external PHY transceiver).  The driver will attempt to guess the proper media type based on
     the PCI device ID word.  The driver makes a lot of noise about this condition because the
     author considers it a manufacturing defect.

     xl%d: transmission error: %d
     xl%d: tx underrun, increasing tx start threshold to %d bytes  This message may appear while
     the adapter tunes its transmission buffers under various load amounts and are mostly
     harmless.  It is probably safe to ignore them.


     altq(4), arp(4), cardbus(4), miibus(4), netintro(4), ng_ether(4), pccard(4), polling(4),


     The xl device driver first appeared in FreeBSD 3.0.


     The xl driver was written by Bill Paul <>.