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em - Intel(R) PRO/1000 Gigabit Ethernet adapter driver

 

NAME

      em - Intel(R) PRO/1000 Gigabit Ethernet adapter driver
 

SYNOPSIS

      To compile this driver into the kernel, place the following line in your
      kernel configuration file:
 
            device em
 
      Alternatively, to load the driver as a module at boot time, place the
      following line in loader.conf(5):
 
            if_em_load="YES"
 

DESCRIPTION

      The em driver provides support for PCI Gigabit Ethernet adapters based on
      the Intel 82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546,
      82546EB, 82546GB, 82547, 82571, 81572 and 82573 Ethernet controller
      chips.  The driver supports Transmit/Receive checksum offload and Jumbo
      Frames on all but 82542-based adapters.  Furthermore it supports TCP seg‐
      mentation offload (TSO) on all adapters but those based on the 82543,
      82544 and 82547 controller chips.  For further hardware information, see
      the README included with the driver.
 
      For questions related to hardware requirements, refer to the documenta‐
      tion supplied with your Intel PRO/1000 adapter.  All hardware require‐
      ments listed apply to use with FreeBSD.
 
      Support for Jumbo Frames is provided via the interface MTU setting.
      Selecting an MTU larger than 1500 bytes with the ifconfig(8) utility con‐
      figures the adapter to receive and transmit Jumbo Frames.  The maximum
      MTU size for Jumbo Frames is 16114.
 
      This driver version supports VLANs.  The em driver supports the following
      media types:
 
      autoselect   Enables auto-negotiation for speed and duplex.
 
      10baseT/UTP  Sets 10Mbps operation.  Use the mediaopt option to select
                   full-duplex mode.
 
      100baseTX    Sets 100Mbps operation.  Use the mediaopt option to select
                   full-duplex mode.
 
      1000baseSX   Sets 1000Mbps operation.  Only full-duplex mode is supported
                   at this speed.
 
      1000baseTX   Sets 1000Mbps operation.  Only full-duplex mode is supported
                   at this speed.
 
      The em driver supports the following media options:
 
      full-duplex  Forces full-duplex operation
 
      half-duplex  Forces half-duplex operation.
 
      Only use mediaopt to set the driver to full-duplex.  If mediaopt is not
      specified, the driver defaults to half-duplex.
 
      For more information on configuring this device, see ifconfig(8).
 

HARDWARE

      The em driver supports Gigabit Ethernet adapters based on the Intel
      82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546, 82546EB,
      82546GB, 82547, 82571, 82572 and 82573 controller chips:
 
            Intel PRO/1000 CT Network Connection (82547)
            Intel PRO/1000 F Server Adapter (82543)
            Intel PRO/1000 Gigabit Server Adapter (82542)
            Intel PRO/1000 GT Desktop Adapter (82541PI)
            Intel PRO/1000 MF Dual Port Server Adapter (82546)
            Intel PRO/1000 MF Server Adapter (82545)
            Intel PRO/1000 MF Server Adapter (LX) (82545)
            Intel PRO/1000 MT Desktop Adapter (82540)
            Intel PRO/1000 MT Desktop Adapter (82541)
            Intel PRO/1000 MT Dual Port Server Adapter (82546)
            Intel PRO/1000 MT Quad Port Server Adapter (82546EB)
            Intel PRO/1000 MT Server Adapter (82545)
            Intel PRO/1000 T Desktop Adapter (82544)
            Intel PRO/1000 T Server Adapter (82543)
            Intel PRO/1000 XF Server Adapter (82544)
            Intel PRO/1000 XT Server Adapter (82544)
      Tunables can be set at the loader(8) prompt before booting the kernel or
      stored in loader.conf(5).
 
      hw.em.rxd
              Number of receive descriptors allocated by the driver.  The
              default value is 256.  The 82542 and 82543-based adapters can
              handle up to 256 descriptors, while others can have up to 4096.
 
      hw.em.txd
              Number of transmit descriptors allocated by the driver.  The
              default value is 256.  The 82542 and 82543-based adapters can
              handle up to 256 descriptors, while others can have up to 4096.
 
      hw.em.rx_int_delay
              This value delays the generation of receive interrupts in units
              of 1.024 microseconds.  The default value is 0, since adapters
              may hang with this feature being enabled.
 
      hw.em.rx_abs_int_delay
              If hw.em.rx_int_delay is non-zero, this tunable limits the maxi‐
              mum delay in which a receive interrupt is generated.
 
      hw.em.tx_int_delay
              This value delays the generation of transmit interrupts in units
              of 1.024 microseconds.  The default value is 64.
 
      hw.em.tx_abs_int_delay
              If hw.em.tx_int_delay is non-zero, this tunable limits the maxi‐
              mum delay in which a transmit interrupt is generated.
 

DIAGNOSTICS

      em%d: Unable to allocate bus resource: memory  A fatal initialization
      error has occurred.
 
      em%d: Unable to allocate bus resource: interrupt  A fatal initialization
      error has occurred.
 
      em%d: watchdog timeout -- resetting  The device has stopped responding to
      the network, or there is a problem with the network connection (cable).
 

SUPPORT

      For general information and support, go to the Intel support website at:
      http://support.intel.com.
 
      If an issue is identified with the released source code on the supported
      kernel with a supported adapter, email the specific information related
      to the issue to 〈freebsdnic@mailbox.intel.com〉.
      altq(4), arp(4), netintro(4), ng_ether(4), polling(4), vlan(4),
      ifconfig(8)
 

HISTORY

      The em device driver first appeared in FreeBSD 4.4.
 

AUTHORS

      The em driver was written by Intel Corporation
      〈freebsdnic@mailbox.intel.com〉.
 

BUGS

      Hardware-assisted VLAN processing is disabled by default.  You can enable
      it on an em interface using ifconfig(8).
 

Sections

Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.