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):
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, 82573, and 82574 Ethernet
controller chips. The driver supports Transmit/Receive checksum offload and
Jumbo Frames on all but 82542-based adapters. Furthermore it supports TCP
segmentation offload (TSO) on all adapters but those based on the 82543, 82544
and 82547 controller chips. The identification LEDs of the adapters supported
by the
em driver can be controlled via the
led(4) API for localization purposes. For further hardware
information, see the
README included with the driver.
For questions related to hardware requirements, refer to the documentation
supplied with your Intel PRO/1000 adapter. All hardware requirements 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
configures 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, 82573, and 82574 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 PF Dual Port
Server Adapter (82571)
- Intel PRO/1000 PF Quad Port
Server Adapter (82571)
- Intel PRO/1000 PF Server
Adapter (82572)
- Intel PRO/1000 PT Desktop
Adapter (82572)
- Intel PRO/1000 PT Dual Port
Server Adapter (82571)
- Intel PRO/1000 PT Quad Port
Server Adapter (82571)
- Intel PRO/1000 PT Server
Adapter (82572)
- 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)
LOADER TUNABLES¶
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 maximum 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 maximum 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⟩.
FILES¶
- /dev/led/em*
- identification LED device nodes
EXAMPLES¶
Make the identification LED of em0 blink:
echo f2 > /dev/led/em0
Turn the identification LED of em0 off again:
echo 0 > /dev/led/em0
SEE ALSO¶
altq(4),
arp(4),
igb(4),
led(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).