Tribblix: manual page: dmfe.4d

DMFE(4D) Devices DMFE(4D)

NAME

dmfe - Davicom Fast Ethernet driver for Davicom DM9102A

SYNOPSIS

/kernel/drv/sparcv9/dmfe

DESCRIPTION

The dmfe Ethernet device provides 100Base-TX networking interfaces
using the Davicom DM9102A chip, which incorporates its own internal
transceiver.

The dmfe driver functions include controller initialization, frame
transmit and receive, promiscuous and multicast support, and error
recovery and reporting. Multiple controllers installed within the
system are supported by the driver.

The 100Base-TX standard specifies an auto-negotiation protocol to
automatically select the mode and speed of operation. The internal
transceiver is capable of performing auto-negotiation with the
remote-end of the link (link partner) and receives the capabilities
of the remote end. It selects the highest common denominator mode of
operation based on the priorities. The internal transceiver also
supports a forced-mode of operation under which the driver selects
the operational mode.

APPLICATION PROGRAMMING INTERFACE

The /dev/dmfe cloning character-special device is used to access all
Davicom DM9102A devices installed in the system.

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. If the ppa field value
does not correspond to a valid device instance number for this
system, an error (DL_ERROR_ACK) is returned. 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 as follows:

o Maximum SDU is 1500 (ETHERMTU - defined in
sys/ethernet.h).

o Minimum SDU is 0.

o DLSAP address length is 8.

o MAC type is DL_ETHER.

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

o The broadcast address value is the Ethernet/IEEE
broadcast address (FF:FF:FF:FF:FF:FF).

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

CONFIGURATION

By default, the dmfe driver performs auto-negotiation to select the
speed and mode of the link. Link speed and mode can be 100 Mbps (full
or half-duplex) or 10 Mbps (full or half-duplex) as described in the
100Base-TX standard.

The auto-negotiation protocol automatically selects speed mode
(either 100 Mbps or 10 Mbps) and operation mode (either full-duplex
or half-duplex) as the highest common denominator supported by both
link partners. Because the dmfe device supports all modes, this
effectively selects the highest-throughput mode supported by the
other device.

Alternatively, you can explicitly specify the link parameters by
adding entries to the dmfe driver configuration file
(/kernel/drv/dmfe.conf). You can set the speed parameter to 10 or 100
to force dmfe devices to operate at the specified speed.
Additionally, you can set the full-duplex parameter to 0 or 1 to
disable or force full-duplex operation, respectively.

Note that specifying either "speed" or "full-duplex" explicitly
disables auto-negotiation. To enable the driver to determine the
appropriate setting for each parameter, you should always set both
parameters. If it is necessary to force either speed or duplex
setting (for example, because the dmfe device is connected to an
ancient device or hub that does not support auto-negotiation), both
parameters should be explicitly specified to match the requirements
of the external device.

FILES

/dev/dmfe
Character special device

/kernel/drv/dmfe
32-bit kernel module (x86)

/kernel/drv/sparcv9/dmfe
64-bit kernel module (SPARC)

/kernel/drv/amd64/dmfe
64-bit kernel module (x86)

/kernel/drv/dmfe.conf
dmfe configuration file

ATTRIBUTES