VR(4) | Device Drivers Manual | VR(4) |
vr
— VIA Rhine
I/II/III 10/100 Ethernet device
vr* at pci?
amphy* at mii?
icsphy* at mii?
sqphy* at mii?
The vr
driver provides support for PCI
Ethernet adapters and embedded controllers based on the VIA Technologies
VT3043 Rhine I, VT86C100A Rhine II, VT6102 Rhine II, and VT6105/VT6105M
Rhine III Fast Ethernet controller chips, including the following:
The VIA Rhine chips use bus master DMA and have a software interface designed to resemble that of the DEC 21x4x "tulip" chips. The major differences are that the receive filter in the Rhine chips is much simpler and is programmed through registers rather than by downloading a special setup frame through the transmit DMA engine, and that on older chips transmit and receive DMA buffers must be longword aligned. The Rhine chips are meant to be interfaced with external physical layer devices via an MII bus. They support both 10 and 100Mbps speeds in either full or half duplex.
The vr
driver for the VT6105M controller
supports IPv4 IP/TCP/UDP transmit/receive checksum offload and VLAN tag
insertion and stripping. The vr
driver additionally
supports Wake on LAN (WoL). See
arp(8) and
ifconfig(8) for more
details.
The vr
driver supports the following media
types:
The vr
driver supports the following media
options:
Note that the 100baseTX media type is only available if supported by the adapter.
For more information on configuring this device, see ifconfig(8).
amphy(4), arp(4), icsphy(4), ifmedia(4), intro(4), netintro(4), pci(4), sqphy(4), hostname.if(5), ifconfig(8)
The VIA Technologies VT86C100A data sheet, http://www.via.com.tw.
The vr
device driver first appeared in
FreeBSD 3.0. OpenBSD support
first appeared in OpenBSD 2.5.
The vr
driver was written by
Bill Paul
<wpaul@ctr.columbia.edu>.
The vr
driver copies transmit mbuf chains
into longword-aligned buffers prior to transmission in order to pacify the
VT3043 and VT86C100A chips. If buffers are not aligned correctly, the chip
will round the supplied buffer address and begin DMAing from the wrong
location. This buffer copying impairs transmit performance on slower systems
but can't be avoided. On faster machines (e.g., a Pentium II), the
performance impact is much less noticeable.
March 15, 2014 | OpenBSD-6.4 |