AWI(4) | Device Drivers Manual | AWI(4) |
awi
— AMD
PCnetMobile IEEE 802.11 PCMCIA wireless network driver
awi* at pcmcia? function ?
The awi
driver supports various IEEE
802.11 wireless cards that run AMD PCnetMobile firmware based on the AMD
79c930 controller with the Intersil (formerly Harris) PRISM radio chipset.
It provides access to 32kb of memory shared between the controller and the
host. All host/device interaction is accomplished via this shared memory,
which can be accessed either via PCMCIA or I/O memory spaces. The
awi
driver encapsulates all IP and ARP traffic in
802.11 frames.
The driver works both in infrastructure mode and in ad-hoc (independent BSS) mode.
In infrastructure mode, it communicates with an Access Point, which serves as a link-layer bridge between an Ethernet segment and the wireless network. An access point also provides roaming capability, which allows a wireless node to move between access points.
In ad-hoc mode, the device communicates peer to peer. Although it is more efficient to communicate between wireless nodes, the coverage is limited spatially due to the lack of roaming capability.
In addition to these two modes in the IEEE 802.11 specification,
the awi
driver also supports a variant of ad-hoc
mode outside of the spec for DS radio cards. This makes it possible to
communicate with the WaveLAN ad-hoc mode of
wi(4) driver. The NWID has no
effect in this mode.
Another mode added to the awi
driver can
be used with old Melco access points with 2Mbps cards. This mode actually
uses the IEEE 802.11 ad-hoc mode with encapsulation of raw Ethernet packets
(including headers) in 802.11 frames.
For more information on configuring this device, see ifconfig(8) and ifmedia(4).
Cards supported by the awi
driver
include:
The original Xircom Netwave AirSurfer is supported by the cnw(4) driver, and the PRISM-II cards are supported by the wi(4) driver.
In addition to default Auto media type, the DS cards support DS1 and DS2 media types, while the FH cards support the FH1 media type. For each media type, the adhoc mediaopt can be used to indicate to the driver to operate in ad-hoc mode. The flag0 mediaopt should be used only with old access points, which operate in IBSS mode. For DS radio cards, the adhoc,flag0 mediaopt can be used for wi(4) compatible WaveLAN ad-hoc mode.
arp(4), cnw(4), ifmedia(4), netintro(4), pcmcia(4), wi(4), ifconfig(8), wiconfig(8)
Am79C930 PCnet Mobile Single-Chip Wireless LAN Media Access Controller, http://www.amd.com.
The awi
device driver first appeared in
NetBSD 1.5.
The initial version of the awi
driver was
written by Bill Sommerfeld
⟨sommerfeld@NetBSD.org⟩. It was then completely rewritten to
support cards with the DS phy and ad-hoc mode by
Atsushi Onoe ⟨onoe@NetBSD.org⟩.
January 2, 2006 | NetBSD 10.99 |