1.\" $NetBSD: gem.4,v 1.6 2008/02/01 11:04:06 jdc Exp $ 2.\" 3.\" Copyright (c) 2002 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the NetBSD 17.\" Foundation, Inc. and its contributors. 18.\" 4. Neither the name of The NetBSD Foundation nor the names of its 19.\" contributors may be used to endorse or promote products derived 20.\" from this software without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32.\" POSSIBILITY OF SUCH DAMAGE. 33.\" 34.Dd February 1, 2007 35.Dt GEM 4 36.Os 37.Sh NAME 38.Nm gem 39.Nd ERI/GEM/GMAC Ethernet device driver 40.Sh SYNOPSIS 41.Cd "gem* at pci? dev ? function ?" 42.Cd "gem* at sbus? slot ? offset ?" 43.Pp 44Configuration of PHYs may also be necessary. 45See 46.Xr mii 4 . 47.Sh DESCRIPTION 48The 49.Nm 50driver provides support for the GMac Ethernet hardware found mostly in 51the last Apple PowerBooks G3s and most G4-based Apple hardware, as 52well as many Sun UltraSPARCs. 53.Pp 54Cards supported by this driver include: 55.Bl -bullet -compact -offset indent 56.It 57Sun GEM gigabit ethernet (including SX fibre variants) 58.It 59Sun ERI 10/100 60.It 61Apple GMAC 62.El 63.Pp 64The GEM family supports hardware checksumming to assist in computing 65IPv4 TCP checksums. 66The 67.Nm 68driver supports this feature of the chip. 69See 70.Xr ifconfig 8 71for information on how to enable this feature. 72.Sh SEE ALSO 73.Xr bmtphy 4 , 74.Xr ifmedia 4 , 75.Xr intro 4 , 76.Xr mii 4 , 77.Xr ifconfig 8 78.Rs 79.%T "GEM Gigabit Ethernet ASIC Specification" 80.%A Sun Microsystems 81.%O http://www.sun.com/processors/manuals/ge.pdf 82.Re 83.Sh HISTORY 84The 85.Nm 86device driver appeared in 87.Nx 1.6 . 88.Sh AUTHORS 89.An -nosplit 90The 91.Nm 92driver was written by 93.An Eduardo Horvath 94.Aq eeh@NetBSD.org . 95The man page was written by 96.An Thomas Klausner 97.Aq wiz@NetBSD.org . 98.Sh BUGS 99The hardware checksumming support does not support IPv4 UDP, although this was 100allowed prior to 101.Nx 5 . 102Also, the hardware IPv4 TCP receive checksumming support has bugs, so this is 103disabled. 104.Pp 105On the SX fibre variants of the hardware, the link will stay down if there is 106a duplex mismatch. 107Also, packet transmission may fail when in 108.Cm half-duplex 109mode. 110