1.\" Copyright (c) 1986, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)enp.4 8.1 (Berkeley) 06/05/93 7.\" 8.Dd 9.Dt ENP 4 tahoe 10.Os BSD 4.3t 11.Sh NAME 12.Nm enp 13.Nd 14.Tn CMC 1510 Mb/s Ethernet interface 16.Sh SYNOPSIS 17.Cd "device enp0 at vba? csr 0xfff40000 vector enpintr" 18.Sh DESCRIPTION 19The 20.Nm enp 21interface provides access to a 10 Mb/s Ethernet network through 22a 23.Tn CMC ENP-20 24controller. 25.Pp 26The hardware has 128 kilobytes of dual-ported memory on the 27.Tn VERSAbus . 28This memory 29is used for internal buffering by the board, and the interface code reads 30the buffer contents directly through the 31.Tn VERSAbus . 32The address of this memory is derived from the address specified 33in the configuration file. 34.Pp 35Each of the host's network addresses 36is specified at boot time with an 37.Dv SIOCSIFADDR 38.Xr ioctl 2 . 39The 40.Nm enp 41interface employs the address resolution protocol described in 42.Xr arp 4 43to dynamically map between Internet and Ethernet addresses on the local 44network. 45.Pp 46The interface normally tries to use a 47.Dq trailer 48encapsulation 49to minimize copying data on input and output. 50The use of trailers is negotiated with 51.Tn ARP . 52This negotiation may be disabled, on a per-interface basis, 53by setting the 54.Dv IFF_NOTRAILERS 55flag with an 56.Dv SIOCSIFFLAGS 57.Xr ioctl . 58.Pp 59Associated with each interface is a character device which 60is used to dowload, start, and reset the firmware in the controller. 61Reading or writing the 62.Dq ram device 63reads or writes the writable 64control store in the controller. Two 65.Xr ioctl 2 66calls, 67.Dv ENPIOGO 68and 69.Dv ENPIORESET , 70are used to start and reset the 71firmware. 72.Sh DIAGNOSTICS 73.Bl -diag 74.It enp%d: can't handle af%d. 75The interface was handed 76a message with addresses formatted in an unsuitable address 77family; the packet was dropped. 78.El 79.Sh SEE ALSO 80.Xr intro 4 , 81.Xr inet 4 , 82.Xr arp 4 , 83.Xr enpload 8 84.Sh HISTORY 85The 86.Nm 87driver appeared in 88.Bx 4.3 tahoe . 89.Sh BUGS 90The hardware is not capable of talking to itself. The software 91implements local sending and broadcast by sending such packets to the 92loop interface. This is a kludge. 93.Pp 94The link level firmware does not support setting the board's 95Ethernet address. 96