A P P E N D I X  B

Application Programming Interface

The cloning character special device /dev/dmfe can be used to access all Davicom DM9102A devices installed in the system. Specific instances can be accessed via the device /dev/dmfe PPA (where PPA stands for Physical Point of Attachment and is effectively the device instance number).

The dmfe driver depends on /kernel/misc/gld , a loadable kernel module that provides the dmfe driver with the DLPI and STREAMS functionality required of a LAN driver. See gld(7D) for more details on the primitives supported by the driver.

Where you open the clone device /dev/dmfe , you must use 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 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 DL_INFO_REQ are shown below.

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

• The minimum SDU is 0.

• The DLSAP address length is 8.

• The MAC type is DL_ETHER.

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

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

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