bge - SUNW,bge Gigabit Ethernet driver for Broadcom BCM57xx




The bge Gigabit Ethernet driver is a multi-threaded, loadable, clonable,
GLD-based STREAMS driver supporting the Data Link Provider Interface,
dlpi(4P), on Broadcom BCM57xx
(BCM5700/5701/5703/5704/5705/5705M/5714/5721/5751/5751M/5782/5788 on x86)
Gigabit Ethernet controllers fitted to the system motherboard. With the
exception of BCM5700/BCM5701/BCM5704S, these devices incorporate both MAC
and PHY functions and provide three-speed (copper) Ethernet operation on
the RJ-45 connectors. (BCM5700/BCM5701/BCM5704S do not have a PHY
integrated into the MAC chipset.)

The bge driver functions include controller initialization, frame
transmit and receive, promiscuous and multicast support, and error
recovery and reporting.

The bge driver and hardware support auto-negotiation, a protocol
specified by the 1000 Base-T standard. Auto-negotiation allows each
device to advertise its capabilities and discover those of its peer (link
partner). The highest common denominator supported by both link partners
is automatically selected, yielding the greatest available throughput,
while requiring no manual configuration. The bge driver also allows you
to configure the advertised capabilities to less than the maximum (where
the full speed of the interface is not required), or to force a specific
mode of operation, irrespective of the link partner's advertised


The cloning character-special device, /dev/bge, is used to access all
BCM57xx devices ( (BCM5700/5701/5703/5704, 5705/5714/5721/5751/5751M/5782
on x86) fitted to the system motherboard.

The bge driver is managed by the dladm(8) command line utility, which
allows VLANs to be defined on top of bge instances and for bge instances
to be aggregated. See dladm(8) for more details.

You must send an explicit DL_ATTACH_REQ message to associate the opened
stream with a particular device (PPA). The PPA ID is interpreted as an
unsigned integer data type and indicates the corresponding device
instance (unit) number. The driver returns an error (DL_ERROR_ACK) if the
PPA field value does not correspond to a valid device instance number for
the system. The device is initialized on first attach and de-initialized
(stopped) at last detach.

The values returned by the driver in the DL_INFO_ACK primitive in
response to a DL_INFO_REQ are:

o Maximum SDU (default 1500).

o Minimum SDU (default 0).

o DLSAP address length is 8.

o MAC type is DL_ETHER.

o SAP length value is -2, meaning the physical address component
is followed immediately by a 2-byte SAP component within the
DLSAP address.

o Broadcast address value is the Ethernet/IEEE broadcast address

Once in the DL_ATTACHED state, you must send a DL_BIND_REQ to associate a
particular Service Access Point (SAP) with the stream.


By default, the bge driver performs auto-negotiation to select the link
speed and mode. Link speed and mode can be any one of the following, (as
described in the IEEE803.2 standard):

o 1000 Mbps, full-duplex

o 1000 Mbps, half-duplex

o 100 Mbps, full-duplex

o 100 Mbps, half-duplex

o 10 Mbps, full-duplex

o 10 Mbps, half-duplex

The auto-negotiation protocol automatically selects:

o Speed (1000 Mbps, 100 Mbps, or 10 Mbps)

o Operation mode (full-duplex or half-duplex)

as the highest common denominator supported by both link partners.
Because the bge device supports all modes, the effect is to select the
highest throughput mode supported by the other device.

Alternatively, you can set the capabilities advertised by the bge device
using dladm(8). The driver supports a number of parameters whose names
begin with en_ (see below). Each of these parameters contains a boolean
value that determines whether the device advertises that mode of
operation. If en_autoneg_cap is set to 0, the driver forces the mode of
operation selected by the first non-zero parameter in priority order as
listed below:

(highest priority/greatest throughput)
en_1000fdx_cap 1000Mbps full duplex
en_1000hdx_cap 1000Mbps half duplex
en_100fdx_cap 100Mbps full duplex
en_100hdx_cap 100Mbps half duplex
en_10fdx_cap 10Mbps full duplex
en_10hdx_cap 10Mbps half duplex
(lowest priority/least throughput)

For example, to prevent the device 'bge2' from advertising gigabit
capabilities, enter (as super-user):

# dladm set-linkprop -p enable_1000hdx_cap=0 bge2
# dladm set-linkprop -p enable_1000fdx_cap=0 bge2

All capabilities default to enabled. Note that changing any capability
parameter causes the link to go down while the link partners renegotiate
the link speed/duplex using the newly changed capabilities.

The current settings of the parameters may be found using dladm show-
ether. In addition, the driver exports the current state, speed, duplex
setting, and working mode of the link via kstat parameters (these are
read only and may not be changed). For example, to check link state of
device bge0:

# dladm show-ether -x bge0
bge0 current up yes 1G-f bi
-- capable -- yes 1G-fh,100M-fh,10M-fh bi
-- adv -- yes 1G-fh bi
-- peeradv -- yes 1G-f bi

The output above indicates that the link is up and running at 1Gbps full-
duplex with its rx/tx direction pause capability.

To extract link state information for the same link using kstat:

# kstat bge:0:mac:link_state
module: bge instance: 0
name: mac class: net

The default MTU is 1500. To enable Jumbo Frames support, you can
configure the bge driver by defining the default_mtu property via
dladm(8) or in driver.conf(5) to greater than 1500 bytes (for example:
default_mtu=9000). Note that the largest jumbo size supported by bge is
9000 bytes. Additionally, not all bge-derived devices currently support
Jumbo Frames. The following devices support Jumbo Frames up to 9KB:
BCM5700, 5701, 5702, 5703C, 5703S, 5704C, 5704S, 5714C, 5714S, 5715C and
5715S. Other devices currently do not support Jumbo Frames.


32-bit ELF kernel module. (x86)

64-bit ELF kernel module (x86).

64-bit ELF kernel module (SPARC).


See attributes(7) for a description of the following attributes:

|Architecture | SPARC, x86 |


streamio(4I), dlpi(4P), driver.conf(5), attributes(7), dladm(8)

Writing Device Drivers

STREAMS Programming Guide

Network Interfaces Programmer's Guide

April 9, 2008 BGE(4D)