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.Dd April 18, 2023
.Dt GEM 4
.Os
.Sh NAME
.Nm gem
.Nd GEM/GMAC Ethernet device driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device miibus"
.Cd "device gem"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_gem_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for the GMAC Ethernet hardware found mostly in
the last Apple PowerBooks G3s and most G4-based Apple hardware.
.Pp
All controllers supported by the
.Nm
driver have TCP checksum offload capability for both receive and transmit,
support for the reception and transmission of extended frames for
.Xr vlan 4
and a 512-bit multicast hash filter.
.Sh HARDWARE
Chips supported by the
.Nm
driver include:
.Pp
.Bl -bullet -compact
.It
Apple GMAC
.It
Sun GEM Gigabit Ethernet
.El
.Pp
The
following add-on cards are known to work with the
.Nm
driver at this time:
.Pp
.Bl -bullet -compact
.It
Sun Gigabit Ethernet PCI 2.0/3.0 (GBE/P)
(part no.\& 501-4373)
.El
.Sh SEE ALSO
.Xr altq 4 ,
.Xr miibus 4 ,
.Xr netintro 4 ,
.Xr vlan 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
device driver appeared in
.Nx 1.6 .
The first
.Fx
version to include it was
.Fx 5.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written for
.Nx
by
.An Eduardo Horvath Aq Mt eeh@NetBSD.org .
It was ported to
.Fx
by
.An Thomas Moestl Aq Mt tmm@FreeBSD.org
and later on improved by
.An Marius Strobl Aq Mt marius@FreeBSD.org .
The man page was written by
.An Thomas Klausner Aq Mt wiz@NetBSD.org .