BWI(4)                    OpenBSD Programmer's Manual                   BWI(4)

NAME
     bwi - Broadcom AirForce IEEE 802.11b/g wireless network device

SYNOPSIS
     bwi* at cardbus?
     bwi* at pci?

DESCRIPTION
     The bwi driver provides support for Broadcom AirForce based PCI/Cardbus
     network adapters.

     These are the modes the bwi driver can operate in:

     BSS mode       Also known as infrastructure mode, this is used when asso-
                    ciating with an access point, through which all traffic
                    passes.  This mode is the default.

     monitor mode   In this mode the driver is able to receive packets without
                    associating with an access point.  This disables the in-
                    ternal receive filter and enables the card to capture
                    packets from networks which it wouldn't normally have ac-
                    cess to, or to scan for access points.

     The bwi driver can be configured to use Wired Equivalent Privacy (WEP) or
     Wi-Fi Protected Access (WPA-PSK and WPA2-PSK).  WPA is the de facto en-
     cryption standard for wireless networks.  It is strongly recommended that
     WEP not be used as the sole mechanism to secure wireless communication,
     due to serious weaknesses in it.  The bwi driver relies on the software
     802.11 stack for both encryption and decryption of data frames.

     The transmit speed is user-selectable or can be adapted automatically by
     the driver depending on the received signal strength and on the number of
     hardware transmission retries.

     The bwi driver can be configured at runtime with ifconfig(8) or on boot
     with hostname.if(5).

FILES
     The driver needs a firmware file which is loaded when an interface is
     brought up:

           /etc/firmware/bwi-airforce

     A prepackaged version of the firmware, designed to be used with
     pkg_add(1), can be found at:

           http://www.nazgul.ch/bwi/bwi-firmware-1.4.tgz

HARDWARE
     The following cards are among those supported by the bwi driver:

           Card                     Chip       Bus        Standard
           Apple Airport Extreme    BCM4306    PCI        b/g
           Apple Airport Extreme    BCM4318    PCI        b/g
           ASUS WL-138g             BCM4318    PCI        b/g
           Buffalo WLI-CB-G54       BCM4306    CardBus    b/g
           Compaq R4035 onboard     BCM4306    PCI        b/g
           HP nx6125                BCM4319    PCI        b/g
           Linksys WPC54G Ver 3     BCM4318    CardBus    b/g
           Linksys WPC54GS Ver 2    BCM4318    CardBus    b/g
           TRENDnet TEW-401PCplus   BCM4306    CardBus    b/g
           US Robotics 5411         BCM4318    CardBus    b/g

EXAMPLES
     The following hostname.if(5) example configures bwi0 to join whatever
     network is available on boot, using WEP key ``0x1deadbeef1'', channel 11,
     obtaining an IP address using DHCP:

           dhcp NONE NONE NONE nwkey 0x1deadbeef1 chan 11

     Configure bwi0 to join network ``my_net'' using WPA-PSK with passphrase
     ``my_passphrase'':

           # ifconfig bwi0 nwid my_net wpa wpapsk \
                   `wpa-psk my_net my_passphrase`

     Return bwi0 to its default settings:

           # ifconfig bwi0 -bssid -chan media autoselect \
                   nwid "" -nwkey -wpa -wpapsk

     Join an existing BSS network, ``my_net'':

           # ifconfig bwi0 192.168.1.1 netmask 0xffffff00 nwid my_net

SEE ALSO
     arp(4), cardbus(4), ifmedia(4), intro(4), netintro(4), pci(4),
     hostname.if(5), ifconfig(8), wpa-psk(8)

HISTORY
     The bwi driver first appeared in OpenBSD 4.3.

AUTHORS
     The bwi driver was written for DragonFlyBSD by Sepherosa Ziehau and port-
     ed to OpenBSD by Jonathan Gray and Marcus Glocker.

CAVEATS
     Some chips are incorrectly calibrated due to the lack of documentation,
     which can slow the amount of traffic to the point of being unusable.
     Furthermore this driver only supports firmware version 3.

OpenBSD 4.7                     January 3, 2010                              2
