[linuxkernelnewbies] b43 - Linux Wireless

Sat, 10 Jan 2009 16:25:57 -0800

http://wireless.kernel.org/en/users/Drivers/b43

b43 and b43legacy

The b43 drivers (bcm43xx in mainline kernels, b43 and b43legacy in wireless-2.6 and 2.6.24 and later) are drivers for the 802.11 B/G family of wireless chips Broadcom produces. The choice of which driver your card uses depends on the revision level of the 802.11 core. This number is read by driver ssb, and the correct choice for your device is made at that point. Note: If your card is a BCM4306 Rev 2, or only has 802.11b capability, it uses b43legacy. All other models use b43.

Contents

  1. b43 and b43legacy
  2. FAQ - Frequently asked questions
  3. caveats
  4. supported
  5. unsupported
  6. available devices
  7. features
  8. donations
  9. support
  10. device firmware
  11. firmware installation
  12. bug reporting
  13. bcm43xx, b43legacy, b43, softmac,... the full story
  14. related tools
  15. external links

FAQ - Frequently asked questions

Please read this whole document and the FAQ before asking any questions to the developers.

caveats

All Broadcom chips require firmware that is loaded onto the wireless chip before it can operate. See below.

If you have an USB device with Broadcom chip, please try the RNDIS driver. The b43/b43legacy driver will never support this device.

supported

  • bcm4303 (802.11b-only chips, uses b43legacy)
  • bcm4306 (Rev. 2 uses b43legacy, Rev. 3 uses b43)
  • bcm4309 (only the 2.4GHz part)
  • bcm4311 rev 1 / bcm4312
  • bcm4311 rev 2 / bcm4312 (needs patches for 2.6.24)
  • bcm4312 (only the 2.4GHz part)
  • bcm4318
  • Note: Broadcom has used some of the BCM43XX designations for more than one flavor of card. To tell for sure if your card is supported, use the command 'lspci -n' and find the line that has the string "14e4:XXXX'. If XXXX is 4301, 4307, 4311, 4312, 4318, 4319, 4320, 4321, 4324, or 4325, the card is supported. All others are NOT supported.

unsupported

  • The 802.11a part of the 4309 and 4312 is not supported.
  • BCM 4310 USB - This device has an LP PHY. We think that means low power. In any case, previous code does not work. The reverse engineers have translated a great deal of the code and are currently generating specs for the code writers. Note: This card uses the PCI buss, despite its name.
  • BCM 4322 802.11a/b/g/n (Has PCI-ID 0x432B) - This device has an N Phy. There is no support for any Draft 802.11n features. We are working on it.
  • BCM 4321 (Has PCI-IDs 0x4328 and 0x4329) - These devices have N Phys. There is no support for any Draft 802.11n features. We are working on it.

available devices

Please see the device list.

features

working

  • Station mode
  • Mesh networking mode
  • Access Point mode (not quite yet, blocked by proper support in mac80211 and hostapd)
  • Ad-Hoc (IBSS) mode
  • Monitor and Promisc mode.
  • "Monitor while operating" and multiple monitor interfaces.
  • In-Hardware traffic de/encryption (relieves your CPU).
  • LEDs to signal card state and traffic.
  • In-Hardware MAC address filter.
  • Packet injection (with radiotap; no FCS injection currently though hardware supports it - a radiotap flag is being discussed for this)
  • Probably something we forgot to add here.

not working yet

  • Interference mitigation.
  • Bluetooth coexistance (most code implemented, but untested)
  • Probably something else that's not listed under "Works".

donations

Many people have donated money, hardware or other services to make this driver possible. Thanks! Please see the donations page for details.

support

IRC channel
irc.freenode.net #bcm-users (English please)
Mailing list

http://lists.berlios.de/mailman/listinfo/bcm43xx-dev

device firmware

firmware installation

The Broadcom wireless chip needs software, called "firmware", that runs on the wireless chip itself during operation. This firmware is copyrighted by Broadcom and it must be extracted from Broadcom's proprietary drivers. To get such firmware on your system, you must download the driver from a legal distribution point, as noted below. Then you must extract the firmware from that Broadcom driver by using b43-fwcutter (or bcm43xx-fwcutter) and install it in the special directory for firmware - usually /lib/firmware. Please note that the firmware from the binary drivers is Copyrighted by Broadcom Corporation and must not be redistributed.

Some distributions have special methods for installing the firmware. In general these consist of a special command entered at a terminal. Because the propietary driver containing the firmware cannot be included in the distribution, you will need a working connection to the Internet. Please post details for distros that are missed at bcm43xx-...@lists.berlios.de.

  1. openSUSE 11.0 and 11.1 use the following command:

    • sudo /usr/sbin/install_bcm43xx_firmware

  2. Ubuntu (all flavors) and Debian use the following command:

    • sudo /usr/share/b43-fwcutter/install_bcm43xx_firmware.sh

  3. Gentoo systems supply a pre-compiled binary for b43-fwcutter. You need to "emerge b43-fwcutter", and then follow the instructions below to download the Broadcom driver. The line that invokes b43-fwcutter will need to be changed to execute the program emerged above.
  4. Mandriva's graphical network card configuration tool, drakconnect, will extract the firmware from the Broadcom driver, which must be downloaded before configuring the card. For versions through 2008 Spring, you will need the V3 driver described below. Beginning with 2009, you will need either the V3 or V4 driver depending on whether your device uses b43legacy or b43. Either the wget command below, or a browser download will get the appropriate file.

Note: If you cannot use your distribution's packages, you need to have a compiler and headers for libc installed. The reason for this requirement is that you will have to build fwcutter.

There are different versions of firmware and tools you may need:

Driver

Kernel

Firmware

Firmware extractor

Instructions

b43

Linux-2.6.24, including 2.6.24-rcX and 2.6.24.Y

4.80.53.0

b43-fwcutter v. 011

Go

b43

Linux-2.6.25 and newer, compat-wireless-2.6 package, current GIT trees

4.150.10.5

b43-fwcutter v. 011

Go

b43legacy

Any

3.130.20.0

b43-fwcutter v. 011

Go

bcm43xx (deprecated)

Any

3.130.20.0

bcm43xx-fwcutter v. 6

Go

To accomplish this task, do the following:

You are using the b43 driver from linux-2.6.24

If you are using the b43 driver from linux-2.6.24, follow these instructions.

Use version 011 of b43-fwcutter.
Download, extract the b43-fwcutter tarball and build it: 

wget http://bu3sch.de/b43/fwcutter/b43-fwcutter-011.tar.bz2
tar xjf b43-fwcutter-011.tar.bz2
cd b43-fwcutter-011
make
cd ..

Use version 4.80.53.0 of Broadcom's proprietary driver.
Download and extract the firmware from this driver tarball: 

export FIRMWARE_INSTALL_DIR="/lib/firmware"
wget http://downloads.openwrt.org/sources/broadcom-wl-4.80.53.0.tar.bz2
tar xjf broadcom-wl-4.80.53.0.tar.bz2
cd broadcom-wl-4.80.53.0/kmod
sudo ../../b43-fwcutter-011/b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" wl_apsta.o

Note that you must adjust the FIRMWARE_INSTALL_DIR path to your distribution. The standard place where firmware is installed to is /lib/firmware. However some distributions put firmware in a different place.

You are using the b43 driver from linux-2.6.25 or newer

Follow these instructions if you are using the b43 driver from linux-2.6.25 and newer or compat-wireless-2.6, or from any current GIT tree.

Use version 011 of b43-fwcutter.
Download, extract the b43-fwcutter tarball and build it: 

wget http://bu3sch.de/b43/fwcutter/b43-fwcutter-011.tar.bz2
tar xjf b43-fwcutter-011.tar.bz2
cd b43-fwcutter-011
make
cd ..

Use version 4.150.10.5 of Broadcom's proprietary driver.
Download and extract the firmware from this driver tarball: 

export FIRMWARE_INSTALL_DIR="/lib/firmware"
wget http://mirror2.openwrt.org/sources/broadcom-wl-4.150.10.5.tar.bz2
tar xjf broadcom-wl-4.150.10.5.tar.bz2
cd broadcom-wl-4.150.10.5/driver
sudo ../../b43-fwcutter-011/b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" wl_apsta_mimo.o

Note that you must adjust the FIRMWARE_INSTALL_DIR path to your distribution. The standard place where firmware is installed to is /lib/firmware. However some distributions put firmware in a different place.

You are using the b43-legacy driver

If you are using the b43legacy driver, follow these instructions.

Use version 011 of b43-fwcutter.
Download, extract the b43-fwcutter tarball and build it: 

wget http://bu3sch.de/b43/fwcutter/b43-fwcutter-011.tar.bz2
tar xjf b43-fwcutter-011.tar.bz2
cd b43-fwcutter-011
make
cd ..

Use version 3.130.20.0 of Broadcom's proprietary driver.
Download and extract the firmware from this driver: 

export FIRMWARE_INSTALL_DIR="/lib/firmware"
wget http://downloads.openwrt.org/sources/wl_apsta-3.130.20.0.o
sudo ./b43-fwcutter-011/b43-fwcutter -w "$FIRMWARE_INSTALL_DIR" wl_apsta-3.130.20.0.o

Note that you must adjust the FIRMWARE_INSTALL_DIR path to your distribution. The standard place where firmware is installed to is /lib/firmware. However some distributions put firmware in a different place.

You are using the deprecated bcm43xx driver

If you are using the old deprecated bcm43xx driver, follow these instructions.

Use version 006 of bcm43xx-fwcutter.
Download, extract the bcm43xx-fwcutter tarball and build it: 

wget http://bu3sch.de/b43/fwcutter/bcm43xx-fwcutter-006.tar.bz2
tar xjf bcm43xx-fwcutter-006.tar.bz2
cd bcm43xx-fwcutter-006
make
cd ..

Use version 3.130.20.0 of Broadcom's proprietary driver.
Download and extract the firmware from this driver: 

export FIRMWARE_INSTALL_DIR="/lib/firmware"
wget http://downloads.openwrt.org/sources/wl_apsta-3.130.20.0.o
sudo ./bcm43xx-fwcutter-006/bcm43xx-fwcutter -w "$FIRMWARE_INSTALL_DIR" wl_apsta-3.130.20.0.o

Note that you must adjust the FIRMWARE_INSTALL_DIR path to your distribution. The standard place where firmware is installed to is /lib/firmware. However some distributions put firmware in a different place.

bug reporting

You should send a message to the b43/b43legacy mailing list at bcm43xx-...@berlios.de containing ALL of the following:

  • A description of the problem at hand
  • When it happens
  • How to reproduce
  • The output of the following commands: 

uname -a

lspci -vvn|grep 43 -A7

dmesg
  • wlan configuration, authentication/encryption type

In addition the following may be of interest to developers:

  • If you have built the kernel from git, tell which tree, and the output of "git describe"
  • If the driver worked with earlier kernels, but has since stopped working, a bisection is of great value.

bcm43xx, b43legacy, b43, softmac,... the full story

The bcm43xx is the old deprecated driver. It is using the ieee80211 + softmac libraries of code shared with other drivers. This stack is deprecated and being replaced by the new mac80211 stack. A new stack implies brand new, re-written driver(s): here come b43 and b43legacy.

What's the difference between b43legacy and b43?

b43 offers a newer codebase and hardware crypto support. Broadcom did not release any version 4 firmware files for some older boards, possibly due to memory constraints on the cards themselves. Stuck with firmware version 3, these cards must use b43legacy which doesn't have hardware crypto support because that has not been reverse engineered completly for version 3 firmware.


bcm43xx

b43legacy

b43

needs firmware

version 3

version 4

extracted by

bcm43xx-fwcutter

b43-fwcutter

depends on

softmac

mac80211

b43legacy should be used on all 4301 and 4303 cards. 4306 and 4309 cards with a MAC core revision of 4 or less should also use b43legacy. b43 should be used on all other cards. You can safely have both versions built on the same system. The full MAC core version is printed in the kernel logs when "SSB debugging" is enabled in KConfig and the driver finds a board. Type "dmesg" to see it. If you are unsure and don't know what we are talking about here, always build both b43 and b43legacy (and get firmware for both too). The kernel autoloader will automatically do the right thing and load the correct driver for your device.

related tools

  • ssb-sprom
    • A tool for the modification of the Broadcom Sonics Silicon Backplane SPROM (e.g. you can permanently change the MAC address or the PCI IDs of your wireless card – useful on some (e.g. Compaq/HP) laptops where the BIOS checks these at boot. It's now part of b43-tools: 
      git clone http://git.bu3sch.de/git/b43-tools.git
    • To use the sprom tool, it is necessary to get a disk copy of your sprom from the /sys file system. The file path for the sprom contents depends on the bus layout of the specific computer being used and will be something like 
      /sys/devices/pci0000:00/0000:00:0d.0/0000:04:00.0/ssb_sprom
    • It is not recommended that you try to type the name. Instead, you should use the following commands to get the working copy: 
      SSB_SPROM=$(find /sys/devices -name ssb_sprom)
echo $SSB_SPROM
    • If the echo command only results in a single instance of "/sys/...", you may proceed. For systems with more than one SSB-based interface, there will be such a string for each, and the command that sets the SSB_SPROM symbol will have to be changed. In the name above, the sequence states that this device is attached to the 0'th PCI bus via bridge 0d.0 and is device 04:00.0 on that bridge. To find which of your SSB devices to select, use the 'lspci -v' command. On my system, the first line of such output for my interface is "04:00.0 Network controller: Broadcom Corporation BCM94311MCG wlan mini-PCI (rev 02)". For this device, one would use 
      SSB_SPROM=$(find /sys/devices -name ssb_sprom | grep 04:00.0)
echo $SSB_SPROM
    • Of course, the "04:00.0" needs to match your system, and check the output value to determine that there is now a single instance of "/sys..." and that the path matches the device whose SPROM is to be changed. If not, adjust the string after 'grep' accordingly.
    • Once the SSB_SPROM variable matches the path to ssb_sprom for your device, get a working copy of the sprom contents with 
      sudo cat $SSB_SPROM > ssb_sprom_copy
    • You may now look at the contents of your sprom with the command 
      ssb-sprom -i ssb_sprom_copy -P
    • As an example, let us suppose that you have purchased a Dell mini-pci card to use in an HP laptop. The HP BIOS refuses to use the card when the pcivendor is Dell (code 0x1028), not HP (code 0x103C). From the information provided by an "ssb-prom –help" command, we learn that the switch needed to change this vendor code is "–subv". To change that code, we use the command 
      ssb-sprom -i ssb_sprom_copy -o new_ssb_sprom_copy --subv 0x103C
    • to write the HP vendor ID to our working copy. I use different input and output files so as not to destroy the original. If further changes are needed, for example the PCI product ID, the command 
      ssb-sprom -i new_ssb_sprom_copy -o new_ssb_sprom_copy --subp 0x137C
    • would be used. Note that the input and output files may be the same.
    • Once you think you have updated correctly, use the following to check the contents: 
      ssb-sprom -i ssb_sprom_copy -P
    • Once the sprom contents are the way you want them, and presumably correct, you are ready to rewrite the file. First, use 
      echo $SSB_SPROM
    • to ensure that this symbol still contains the SPROM path. If not, then it will have to be reloaded as discussed above.
    • You are then ready to rewrite the sprom with 
      sudo cp new_ssb_sprom_copy $SSB_SPROM
    • Once again, you are urged to be absolutely certain of the contents of the working copy BEFORE taking this step. If your interface becomes unusable as a result of writing incorrect data into the sprom, the responsibility is YOURS. Once again, you have been warned.
  • A firmware assembler/disassembler can be found in the git repository at
  • There are more development and debugging tools available in the b43-tools git repository. Just clone it and read the shipped documentation files.
  • wpa_supplicant
    • A tool for enabling WPA and full IEEE 802.11i/RSN/WPA2 WPA-PSK and WPA2-PSK (pre-shared key) ("WPA-Personal") WPA with EAP.
    • wpa_supplicant may have a 'broadcom' driver that is used with the proprietary Broadcom driver. The bcm43xx, b43 and b43legacy drivers use the linux wireless extensions properly and so need the wext driver. This is set using the -D option like this: 
    • wpa_supplicant -iwlan0 -Dwext -c/etc/wpa_supplement.conf

    • Of course, you don't need this if you're using NetworkManager.

external links

Broadcom Wireless-LAN section

Reply via email to