HME(4D) Devices HME(4D)

NAME

hme - SUNW,hme Fast-Ethernet device driver

SYNOPSIS

/dev/hme

DESCRIPTION

The SUNW,hme Fast-Ethernet driver is a multi-threaded, loadable,
clonable, STREAMS hardware driver supporting the connectionless Data
Link Provider Interface, dlpi(4P), over a SUNW,hme Fast-Ethernet
controller. The motherboard and add-in SBus SUNW,hme controllers of
several varieties are supported. Multiple SUNW,hme controllers
installed within the system are supported by the driver.


The hme driver provides basic support for the SUNW,hme hardware. It
is used to handle the SUNW,hme device. Functions include chip
initialization, frame transit and receive, multicast and promiscuous
support, and error recovery and reporting. SUNW,hme The SUNW,hme
device provides 100Base-TX networking interfaces using SUN's FEPS
ASIC and an Internal Transceiver. The FEPS ASIC provides the Sbus
interface and MAC functions and the Physical layer functions are
provided by the Internal Transceiver which connects to a RJ-45
connector. In addition to the RJ-45 connector, an MII (Media
Independent Interface) connector is also provided on all SUNW,hme
devices except the SunSwith SBus adapter board. The MII interface is
used to connect to an External Transceiver which may use any physical
media (copper or fiber) specified in the 100Base-TX standard. When an
External Transceiver is connected to the MII, the driver selects the
External Transceiver and disables the Internal Transceiver.


The 100Base-TX standard specifies an "auto-negotiation" protocol to
automatically select the mode and speed of operation. The Internal
transceiver is capable of doing "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. It also supports forced-mode of
operation where the driver can select the mode of operation.

APPLICATION PROGRAMMING INTERFACE

The cloning character-special device /dev/hme is used to access all
SUNW,hme controllers installed within the system.

hme and DLPI
The hme driver is a "style 2" Data Link Service provider. All
M_PROTO and M_PCPROTO type messages are interpreted as DLPI
primitives. Valid DLPI primitives are defined in <sys/dlpi.h>. Refer
to dlpi(4P) for more information. An explicit DL_ATTACH_REQ message
by the user is required to associate the opened stream with a
particular device (ppa). The ppa ID is interpreted as an unsigned
long data type and indicates the corresponding device instance (unit)
number. An error (DL_ERROR_ACK) is returned by the driver if the ppa
field value does not correspond to a valid device instance number for
this 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 the DL_INFO_REQ from the user are as follows:

o The maximum SDU is 1500 (ETHERMTU - defined in
<sys/ethernet.h> ).

o The minimum SDU is 0.

o The dlsap address length is 8.

o The MAC type is DL_ETHER.

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

o The service mode is DL_CLDLS.

o No optional quality of service (QOS) support is included
at present so the QOS fields are 0.

o The provider style is DL_STYLE2.

o The version is DL_VERSION_2.

o The broadcast address value is Ethernet/IEEE broadcast
address (0xFFFFFF).


Once in the DL_ATTACHED state, the user must send a DL_BIND_REQ to
associate a particular SAP (Service Access Pointer) with the stream.
The hme driver interprets the sap field within the DL_BIND_REQ as an
Ethernet "type" therefore valid values for the sap field are in the
[0-0xFFFF] range. Only one Ethernet type can be bound to the stream
at any time.


If the user selects a sap with a value of 0, the receiver will be in
"802.3 mode". All frames received from the media having a "type"
field in the range [0-1500] are assumed to be 802.3 frames and are
routed up all open Streams which are bound to sap value 0. If more
than one Stream is in "802.3 mode" then the frame will be duplicated
and routed up multiple Streams as DL_UNITDATA_IND messages.


In transmission, the driver checks the sap field of the DL_BIND_REQ
if the sap value is 0, and if the destination type field is in the
range [0-1500]. If either is true, the driver computes the length of
the message, not including initial M_PROTO mblk (message block), of
all subsequent DL_UNITDATA_REQ messages and transmits 802.3 frames
that have this value in the MAC frame header length field.


The hme driver DLSAP address format consists of the 6 byte physical
(Ethernet) address component followed immediately by the 2 byte sap
(type) component producing an 8 byte DLSAP address. Applications
should not hardcode to this particular implementation-specific DLSAP
address format but use information returned in the DL_INFO_ACK
primitive to compose and decompose DLSAP addresses. The sap length,
full DLSAP length, and sap/physical ordering are included within the
DL_INFO_ACK. The physical address length can be computed by
subtracting the sap length from the full DLSAP address length or by
issuing the DL_PHYS_ADDR_REQ to obtain the current physical address
associated with the stream.


Once in the DL_BOUND state, the user may transmit frames on the
Ethernet by sending DL_UNITDATA_REQ messages to the hme driver. The
hme driver will route received Ethernet frames up all those open and
bound streams having a sap which matches the Ethernet type as
DL_UNITDATA_IND messages. Received Ethernet frames are duplicated
and routed up multiple open streams if necessary. The DLSAP address
contained within the DL_UNITDATA_REQ and DL_UNITDATA_IND messages
consists of both the sap (type) and physical (Ethernet) components.


In addition to the mandatory connectionless DLPI message set the
driver additionally supports the following primitives.

hme Primitives
The DL_ENABMULTI_REQ and DL_DISABMULTI_REQ primitives enable/disable
reception of individual multicast group addresses. A set of multicast
addresses may be iteratively created and modified on a per-stream
basis using these primitives. These primitives are accepted by the
driver in any state following DL_ATTACHED.


The DL_PROMISCON_REQ and DL_PROMISCOFF_REQ primitives with the
DL_PROMISC_PHYS flag set in the dl_level field enables/disables
reception of all ("promiscuous mode") frames on the media including
frames generated by the local host. When used with the DL_PROMISC_SAP
flag set this enables/disables reception of all sap (Ethernet type)
values. When used with the DL_PROMISC_MULTI flag set this
enables/disables reception of all multicast group addresses. The
effect of each is always on a per-stream basis and independent of the
other sap and physical level configurations on this stream or other
streams.


The DL_PHYS_ADDR_REQ primitive returns the 6 octet Ethernet address
currently associated (attached) to the stream in the DL_PHYS_ADDR_ACK
primitive. This primitive is valid only in states following a
successful DL_ATTACH_REQ.


The DL_SET_PHYS_ADDR_REQ primitive changes the 6 octet Ethernet
address currently associated (attached) to this stream. The
credentials of the process which originally opened this stream must
be superuser. Otherwise EPERM is returned in the DL_ERROR_ACK. This
primitive is destructive in that it affects all other current and
future streams attached to this device. An M_ERROR is sent up all
other streams attached to this device when this primitive is
successful on this stream. Once changed, all streams subsequently
opened and attached to this device will obtain this new physical
address. Once changed, the physical address will remain until this
primitive is used to change the physical address again or the system
is rebooted, whichever comes first.

hme DRIVER
By default, the hme driver performs "auto-negotiation" to select the
mode and speed of the link, when the Internal Transceiver is used.


When an External Transceiver is connected to the MII interface, the
driver selects the External Transceiver for networking operations.
If the External Transceiver supports "auto-negotiation", the driver
uses the auto-negotiation procedure to select the link speed and
mode. If the External Transceiver does not support auto-negotiation,
it will select the highest priority mode supported by the
transceiver.

o 100 Mbps, full-duplex

o 100 Mbps, half-duplex

o 10 Mbps, full-duplex

o 10 Mbps, half-duplex


The link can be in one of the 4 following modes:


These speeds and modes are described in the 100Base-TX standard.


The auto-negotiation protocol automatically selects:

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

o Speed (100 Mbps or 10 Mbps)


The auto-negotiation protocol does the following:

o Gets all the modes of operation supported by the Link
Partner

o Advertises its capabilities to the Link Partner

o Selects the highest common denominator mode of operation
based on the priorities


The internal transceiver is capable of all of the operating speeds
and modes listed above. When the internal transceiver is used, by
default, auto-negotiation is used to select the speed and the mode of
the link and the common mode of operation with the Link Partner.


When an external transceiver is connected to the MII interface, the
driver selects the external transceiver for networking operations. If
the external transceiver supports auto-negotiation:

o The driver uses the auto-negotiation procedure to select
the link speed and mode.


If the external transceiver does not support auto-negotiation

o The driver selects the highest priority mode supported by
the transceiver.


Sometimes, the user may want to select the speed and mode of the
link. The SUNW,hme device supports programmable "IPG" (Inter-Packet
Gap) parameters ipg1 and ipg2. By default, the driver sets ipg1 to 8
byte-times and ipg2 to 4 byte-times (which are the standard values).
Sometimes, the user may want to alter these values depending on
whether the driver supports 10 Mbps or 100 Mbps and accordingly, IPG
will be set to 9.6 or 0.96 microseconds.

hme Parameter List
The hme driver provides for setting and getting various parameters
for the SUNW,hme device. The parameter list includes:
current transceiver status
current link status
inter-packet gap
local transceiver capabilities
link partner capabilities


The local transceiver has two set of capabilities: one set reflects
the capabilities of the hardware, which are read-only (RO)
parameters and the second set reflects the values chosen by the user
and is used in speed selection. There are read/write (RW)
capabilities. At boot time, these two sets of capabilities will be
the same. The Link Partner capabilities are also read only
parameters because the current default value of these parameters can
only be read and cannot be modified.

FILES

/dev/hme
hme special character device


/kernel/drv/hme.conf
System-wide default device driver properties

SEE ALSO

dlpi(4P), driver.conf(5), ndd(8), netstat(8)

September 5, 1995 HME(4D)