Broadcom 43xx

This article details the configuration of Broadcom 43xx series devices by three different methods:  Using the open source driver provided in the Linux kernel Using NDISwrapper Using the binary/proprietary Broadcom 802.11 Linux STA driver 

It is important to know whether or not your specific Broadcom device is supported. This info and other worthwhile reading is available below...

Models supported by the open-source "b43" driver (available in any modern kernel) Models supported by the open-source "brcm80211" driver (available only in kernel 2.6.37 and above) Models supported by the proprietary binary broadcom-sta driver (available in the Portage tree)

There may be other Broadcom drivers coming to the Linux kernel for the 3.2 release (more info). Note that this article only covers the specifics required for these devices. For generic installation instructions please see the Gentoo Handbook.

= Open Source Kernel Driver =

Note: Most recent kernels offer the standard open source "b43" driver, the main subject of this article. In Linux Kernel 2.6.37 the new Broadcom open source driver is available for BCM4313, BCM43224, and BCM43225 (explained further here and here and here).

First, enable the following options in the kernel, then build and install as normal. The deselected options are possible extras or alternatives, depending on your device. (The instructions below are for the traditional "b43" kernel driver. The kernel configuration for the new Broadcom "brcm80211" driver can be seen here)

(*) Broadcom 43xx-legacy data transfer mode (DMA + PIO) kernel option reports that "not all devices of the b43legacy series support PIO. You should use PIO only if DMA does not work for you."

The following options may enable support for laptop LEDs.

Firmware
In addition to the kernel driver, you will need the firmware for your card.

Kernel >=2.6.32
You can install the firmware from portage tree without fwcutter:

Older Kernels
For manual installation you will need a firmware cutter (which extracts the firmware and places it in )

Install the firmware cutter with:

Download the appropriate firmware file from the documentation site.

Now extract the firmware file (replacing the example used below with the version of firmware recommended by the b43 documentation):

then

If does not exist, create it:

Cut the firmware with:

brcm80211
The firmware is available in

Loading the Module
If you opted to compile the driver as a module, it will be named either b43 or b43legacy depending on which you chose.

or

For most users, installation should now be complete. Reboot and configure your wireless.

Optional: Monitor mode
If you want monitor mode, you will need to patch the kernel driver. If you don't know what Monitor Mode means, you probably don't need it.

Generally, monitor mode is only needed for networking research and packet injection by aircrack-ng and similar tools.

You can find documentation on these patches on the aircrack-ng website. The patches themselves can be downloaded from http://patches.aircrack-ng.org/

It is best to use the wireless testing kernel to patch against:

Kernel 2.6.25
= Ndiswrapper - Wrapping Windows Drivers = If the process above doesn't work, you can try to use the ndiswrapper drivers which are the drivers that came with your laptop or wireless card. If those fail, check for the latest version from the manufacturers website.

If you own a macbook (4th or 5th generation) try using the bootcamp winxp driver. It's located on the 1st install DVD and named "broadcomxpinstaller.exe", just unrar it.

Then just follow Ndiswrapper.

= Broadcom 802.11 Linux STA driver = Broadcom has released its own kernel driver. It's closed source but works and seems to release "often" (at least 3 times between the summer of 2008 and the February 2009). However, there has been no new releases since December, 2010.

There is now an ebuild for this binary Broadcom-provided kernel module. The ebuild also contains patches so that it will work on the latest kernel. Just accept the license (by adding "Broadcom" to ACCEPT_LICENSE in /etc/make.conf), and emerge as usual.

Optional: Monitor mode
Since 5.100.82.111 broadcom-sta driver supports monitor mode. To enable it run

and to disable:

When monitor mode is enabled, prism0 network interface appears. This interface can be used by wireshark, airodump-ng, etc to scan wireless network traffic.

= Troubleshooting =

General Advice
Your first port of call when problems arise is the output of dmesg, which displays the kernel log. It is also helpful to make sure that only one of the 3 possible modules is loading. The best way to do this is blacklist the modules you don't want. Add the relevant entries from below.

WEP encryption is not enabled for your device
If you get an error message saying "WEP encryption is not enabled for your device" or similar it may be necessary to compile the following into the kernel to ensure that the required cryptographic options are enabled. If you compile the cryptographic options as modules, they may not be loaded automatically by the driver.

iwconfig reports txpower off
On some laptops the driver does not initialise the device in powered on mode. This can be resolved by adding the following to your network configuration (assuming wlan0 is the device name).

WPA authentication doesn't work with broadcom-sta
If authentication fails with broadcom-sta, you probably need to enable Host AP (CONFIG_HOSTAP).

= (Old) Device Support List for 43xx Open Source Driver =

This table is *incomplete*, and probably out of date. If your card is unlisted, that doesn't mean that it isn't supported.

For an up-to-date list for the in-kernel (open source) 43XX driver, read http://wireless.kernel.org/en/users/Drivers/b43/devices

(*) N-series Broadcom chips are not supported by any of the 43xx drivers in Linux at this time (August 2008) - https://lists.berlios.de/pipermail/bcm43xx-dev/2008-May/007517.html

Related Links

 * bcm43xx project
 * bcm43xx documentation
 * b43 and b43-legacy documentation
 * Gentoo Handbook: Networking
 * Broadcom devices in the pciid database
 * Broadcom's driver site

B43