xref: /csrg-svn/share/man/man4/man4.tahoe/enp.4 (revision 61588)
1*61588Sbostic.\" Copyright (c) 1986, 1991, 1993
2*61588Sbostic.\"	The Regents of the University of California.  All rights reserved.
333029Sbostic.\"
443580Strent.\" %sccs.include.redist.man%
533029Sbostic.\"
6*61588Sbostic.\"     @(#)enp.4	8.1 (Berkeley) 06/05/93
736754Sbostic.\"
847673Scael.Dd
947673Scael.Dt ENP 4 tahoe
1047673Scael.Os BSD 4.3t
1147673Scael.Sh NAME
1247673Scael.Nm enp
1347673Scael.Nd
1447673Scael.Tn CMC
1547673Scael10 Mb/s Ethernet interface
1647673Scael.Sh SYNOPSIS
1747673Scael.Cd "device enp0 at vba? csr 0xfff40000 vector enpintr"
1847673Scael.Sh DESCRIPTION
1933029SbosticThe
2047673Scael.Nm enp
2133029Sbosticinterface provides access to a 10 Mb/s Ethernet network through
2247673Scaela
2347673Scael.Tn CMC ENP-20
2447673Scaelcontroller.
2547673Scael.Pp
2647673ScaelThe hardware has 128 kilobytes of dual-ported memory on the
2747673Scael.Tn VERSAbus .
2833029SbosticThis memory
2933029Sbosticis used for internal buffering by the board, and the interface code reads
3047673Scaelthe buffer contents directly through the
3147673Scael.Tn VERSAbus .
3233029SbosticThe address of this memory is derived from the address specified
3333029Sbosticin the configuration file.
3447673Scael.Pp
3533029SbosticEach of the host's network addresses
3647673Scaelis specified at boot time with an
3747673Scael.Dv SIOCSIFADDR
3847673Scael.Xr ioctl 2 .
3947673ScaelThe
4047673Scael.Nm enp
4133029Sbosticinterface employs the address resolution protocol described in
4247673Scael.Xr arp 4
4333029Sbosticto dynamically map between Internet and Ethernet addresses on the local
4433029Sbosticnetwork.
4547673Scael.Pp
4647673ScaelThe interface normally tries to use a
4747673Scael.Dq trailer
4847673Scaelencapsulation
4933029Sbosticto minimize copying data on input and output.
5047673ScaelThe use of trailers is negotiated with
5147673Scael.Tn ARP .
5233029SbosticThis negotiation may be disabled, on a per-interface basis,
5347673Scaelby setting the
5447673Scael.Dv IFF_NOTRAILERS
5547673Scaelflag with an
5647673Scael.Dv SIOCSIFFLAGS
5747673Scael.Xr ioctl .
5847673Scael.Pp
5933029SbosticAssociated with each interface is a character device which
6033029Sbosticis used to dowload, start, and reset the firmware in the controller.
6147673ScaelReading or writing the
6247673Scael.Dq ram device
6347673Scaelreads or writes the writable
6433029Sbosticcontrol store in the controller.  Two
6547673Scael.Xr ioctl 2
6647673Scaelcalls,
6747673Scael.Dv ENPIOGO
6847673Scaeland
6947673Scael.Dv ENPIORESET ,
7047673Scaelare used to start and reset the
7133029Sbosticfirmware.
7247673Scael.Sh DIAGNOSTICS
7347673Scael.Bl -diag
7447673Scael.It enp%d: can't handle af%d.
7533029SbosticThe interface was handed
7633029Sbostica message with addresses formatted in an unsuitable address
7733029Sbosticfamily; the packet was dropped.
7847673Scael.El
7947673Scael.Sh SEE ALSO
8047673Scael.Xr intro 4 ,
8147673Scael.Xr inet 4 ,
8247673Scael.Xr arp 4 ,
8347673Scael.Xr enpload 8
8447673Scael.Sh HISTORY
8547673ScaelThe
8647673Scael.Nm
8747673Scaeldriver appeared in
8847673Scael.Bx 4.3 tahoe .
8947673Scael.Sh BUGS
9033029SbosticThe hardware is not capable of talking to itself.  The software
9133029Sbosticimplements local sending and broadcast by sending such packets to the
9233029Sbosticloop interface.  This is a kludge.
9347673Scael.Pp
9433029SbosticThe link level firmware does not support setting the board's
9533029SbosticEthernet address.
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