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 1024 for adapters newer than 82547, and 256 for older ones. 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 1024 for adapters newer than 82547, and 256 for older ones. 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.
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
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 ⟨freebsd@intel.com⟩.
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
⟨freebsd@intel.com⟩.
BUGS¶
Hardware-assisted VLAN processing is disabled by default. You can enable it on
an
em
interface using
ifconfig(8).