BWFM(4) - Device Drivers Manual #

BWFM(4) - Device Drivers Manual

NAME #

bwfm - Broadcom and Cypress IEEE 802.11a/ac/ax/b/g/n wireless network device

SYNOPSIS #

bwfm* at pci? bwfm* at sdmmc? bwfm* at usb?

DESCRIPTION #

The bwfm driver provides support for Broadcom and Cypress FullMAC wireless network adapters.

The following table summarizes supported chipsets and their capabilities, as well as the bus attachments recognized by the bwfm driver:

*Chipset*  *Spectrum*  *Type* *MIMO* *Bus*  
BCM43143   2GHz        11n    1x1    SDMMC/USB  
BCM43236   2GHz/5GHz   11n    2x2    USB  
BCM4324    2GHz/5GHz   11n    2x2    SDMMC  
BCM43242   2GHz/5GHz   11n    2x2    USB  
BCM4329    2GHz/5GHz   11n    2x2    SDMMC  
BCM4330    2GHz/5GHz   11n    2x2    SDMMC  
BCM4334    2GHz/5GHz   11n    2x2    SDMMC  
BCM43340   2GHz/5GHz   11n    1x1    SDMMC  
BCM43341   2GHz/5GHz   11n    1x1    SDMMC  
BCM4335    2GHz/5GHz   11ac   1x1    SDMMC  
BCM43362   2GHz        11n    1x1    SDMMC  
BCM43364   2GHz        11n    1x1    SDMMC  
BCM4339    2GHz/5GHz   11ac   1x1    SDMMC  
BCM43430   2GHz        11n    1x1    SDMMC  
BCM43455   2GHz/5GHz   11ac   1x1    SDMMC  
BCM43456   2GHz/5GHz   11ac   2x2    SDMMC  
BCM4350    2GHz/5GHz   11ac   2x2    PCI  
BCM4354    2GHz/5GHz   11ac   2x2    SDMMC  
BCM4356    2GHz/5GHz   11ac   2x2    PCI/SDMMC  
BCM43569   2GHz/5GHz   11ac   2x2    USB  
BCM43602   2GHz/5GHz   11ac   3x3    PCI  
BCM4371    2GHz/5GHz   11ac   2x2    PCI  
BCM4378    2GHz/5GHz   11ax   2x2    PCI  
BCM4387    2GHz/5GHz   11ax   2x2    PCI

These are the modes the bwfm driver can operate in:

BSS mode

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

Host AP

In this mode the driver acts as an access point (base station) for other cards.

The bwfm driver can be configured to use Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA1 and WPA2). WPA2 is the current encryption standard for wireless networks. It is strongly recommended that neither WEP nor WPA1 are used as the sole mechanism to secure wireless communication, due to serious weaknesses. WPA1 is disabled by default and may be enabled using the option “wpaprotos wpa1,wpa2”. For standard WPA networks which use pre-shared keys (PSK), keys are configured using the “wpakey” option. WPA-Enterprise networks require use of the wpa_supplicant package. The bwfm driver relies on the software 802.11 stack for the WPA handshake. Both encryption and decryption of data frames are handled by the firmware.

The firmware automatically selects the transmit speed and the channel depending on the received signal strength.

The bwfm 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 the driver attaches. A prepackaged version of the firmware can be installed using fw_update(8).

EXAMPLES #

The following example scans for available networks:

# ifconfig bwfm0 scan

The following hostname.if(5) example configures bwfm0 to join network “mynwid”, using WPA key “mywpakey”, obtaining an IP address using DHCP:

nwid mynwid wpakey mywpakey
inet autoconf

The following hostname.if(5) example creates a host-based access point on boot:

mediaopt hostap
nwid mynwid wpakey mywpakey
inet 192.168.1.1 255.255.255.0

HISTORY #

The bwfm driver first appeared in OpenBSD 6.3.

AUTHORS #

The bwfm driver was written by Patrick Wildt <patrick@blueri.se>.

CAVEATS #

The firmware is outdated and contains known vulnerabilities.

This driver does not support powersave mode.

OpenBSD 7.5 - March 21, 2023