Making Wireless work on your laptop (or desktop)

Broadcom Corporation BCM4311, BCM4312, BCM4313, BCM4321 or BCM4322 Based Wireless NICs

These chipsets are not natively supported by CentOS.

This page is currently maintained by:

NOTE: Due to an excessively restrictive license accompanying this Broadcom driver, the ELRepo repository developers have refrained from supplying it via an rpm package - hence this manual was created with the purpose of providing a single comprehenssive driver installation manual.

NOTE: Only Broadcom BCM4311 and BCM4312 chips have been tested by the author so far.

Contents

In order to install Broadcom BCM4311, BCM4312,BCM4313, BCM4321 or BCM4322 based wireless network cards, the next steps should be followed:

Step 1: Determining WLAN chip and installing dependencies

First of all, make sure you are the "proud owner of Broadcom BCM43xx wireless card":

[user@host ~]$ /sbin/lspci | grep Broadcom
0b:00.0 Network controller: Broadcom Corporation BCM4312 802.11a/b/g (rev 01)

After the WLAN chip model was determined, make sure you have no missing packages needed at compile-time and install them if you do:

[root@host ~]# yum install kernel-headers kernel-devel gcc

Of course, if you're compiling the driver for Xen kernel (i.e. kernel-xen), you should install kernel-xen-devel instead of kernel-devel.

Step 2: Downloading and extracting Broadcom driver archive

Download the Broadcom BCM43xx linux driver archive from to your machine and extract it to /usr/local/src/hybrid-wl and feel free to change the ownership of the directory and it's contents to some unprivileged user

[root@host ~]# mkdir -p /usr/local/src/hybrid-wl
[root@host hybrid-wl]# cd /usr/local/src/hybrid-wl
[root@host hybrid-wl]# tar xvfz /path/to/the/tarball/hybrid-portsrc-x86_64-v5.10.91.9.3.tar.gz (name of the downloaded file)
[root@host hybrid-wl]# chown -R someuser.somegroup /usr/local/src/hybrid-wl

NOTE: Why not extract it to arbitrary location and leave the ownership it is? Well, this way the driver module sources remain on the system - where you left them - so you can build the driver module whenever you want (e.g. in case you upgrade the kernel - since driver modules are always compiled for a particular kernel), plus, you can do this as an unprivileged user!

Step 3: Compiling the Broadcom driver module

Driver module can be compiled as follows:

[user@host hybrid-wl]$ make -C /lib/modules/`uname -r`/build/ M=`pwd`

Mind the quotes (i.e. back quotes).

Now, it's very likely you'll get an error message instead of compiled driver module (in fact, different scenario other that this error message is unknown to the author). The message should look something like this:

make: Entering directory `/usr/src/kernels/2.6.18-164.el5-x86_64'
  LD      /tmp/hybrid/hybrid/hybrid/built-in.o
  CC [M]  /tmp/hybrid/hybrid/hybrid/src/wl/sys/wl_linux.o
In file included from /tmp/hybrid/hybrid/hybrid/src/wl/sys/wl_linux.c:20:
/tmp/hybrid/hybrid/hybrid/src/include/typedefs.h:70: error: conflicting types for ‘bool’
include/linux/types.h:36: error: previous declaration of ‘bool’ was here
make[1]: *** [/tmp/hybrid/hybrid/hybrid/src/wl/sys/wl_linux.o] Error 1
make: *** [_module_/tmp/hybrid/hybrid/hybrid] Error 2
make: Leaving directory `/usr/src/kernels/2.6.18-164.el5-x86_64'

As you can see, there is a problem with the typedefs.h file at the line 70. To overcome this, comment out block of code beginning at line 70, so it would look like this:

/*
#ifndef TYPEDEF_BOOL
typedef  unsigned char  bool;
#endif
*/

This may also be resolved by simply adding the line below at header (regardless the fact that one such line already exists):

#define TYPEDEF_BOOL

Now, try compiling the driver module again:

[user@host hybrid-wl]$ make -C /lib/modules/`uname -r`/build/ M=`pwd`

and the compile output should look something like this:

make: Entering directory `/usr/src/kernels/2.6.18-164.el5-x86_64'
  CC [M]  /tmp/hybrid/hybrid/hybrid/src/wl/sys/wl_linux.o
  CC [M]  /tmp/hybrid/hybrid/hybrid/src/wl/sys/wl_iw.o
  CC [M]  /tmp/hybrid/hybrid/hybrid/src/shared/linux_osl.o
  LD [M]  /tmp/hybrid/hybrid/hybrid/wl.o
  Building modules, stage 2.
  MODPOST
  CC      /tmp/hybrid/hybrid/hybrid/wl.mod.o
  LD [M]  /tmp/hybrid/hybrid/hybrid/wl.ko
make: Leaving directory `/usr/src/kernels/2.6.18-164.el5-x86_64'

The module, once built, can be stripped of unnecessary symbols:

[user@host hybrid-wl]$ strip --strip-debug wl.ko

What you will notice, is that driver module file size reduces significantly (from 2.2MB to 1.5MB). And yes, your driver module works

Step 4a: Loading the driver module into kernel

Having successfully compiled the driver module, you can now load it into kernel and set up automatic driver load on system boot (to do this, you'll have to assume root privileges). Of course, all this can only be done only after you remove the existing wireless driver modules from kernel (in case these are loaded):

[root@host ~]# rmmod bcm43xx
[root@host ~]# rmmod b43
[root@host ~]# rmmod b43legacy
[root@host ~]# rmmod ndiswrapper

and now load the driver module:

[root@host hybrid-wl]# insmod wl.ko

In case this fails (there have been quite a few reports, however, this kind of behavior has not yet been witnessed by the author), with an error message like:

insmod: error inserting 'wl.ko': -1 Unknown symbol in module

Try building the module dependencies first:

[root@host ~]# depmod `uname -r`

and then load the driver module:

[root@host hybrid-wl]# modprobe wl

The 'ndiswrapper' kernel module can be removed provided you didn't use it for anything else but wireless driver, but this is not necessary.

Step 4b: Loading the driver module into kernel on boot time

First of all, copy the driver module file to a location where kernel can find it:

[root@host hybrid-wl]# cp -vi /usr/local/src/hybrid-wl/wl.ko /lib/modules/`uname -r`/extra/

to be consistent with all other external modules that have been / may be installed from a kmod packages (e.g. fuse, ntfs-3g, etc.)

Next, run:

[root@host ~]# depmod $(uname -r)

in order to create a list of module dependencies.

Edit the /etc/modprobe.d/blacklist file adding the lines:

blacklist bcm43xx
blacklist ndiswrapper
blacklist b43
blacklist b43legacy

By doing so, you're preventing these modules from being loaded into kernel at boot time. Also, if there is a line in the /etc/modprobe.conf assigning the driver to your wireless interface, like:

alias eth1 bcm43xx
 or
alias eth1 b43
 or
alias eth1 b43legacy

have the line commented out:

#alias eth1 bcm43xx
 or
#alias eth1 b43
 or
#alias eth1 b43legacy

and add the new driver alias for your wireless card:

alias eth1 wl

All this assuming the device file for your wireless interface is 'eth1'.

Now, edit the /etc/modprobe.d/modprobe.conf.dist file and add the following lines to it (in some cases, the following may not be necessary):

alias ieee80211_crypt_tkip ieee80211_crypt_tkip
alias eth1 wl

Your driver should now load every time you reboot (except of course, when you install the new kernel, in which case the driver has to be re-compiled for it following these same steps).

ATTENTION: This driver module is NOT persistent across kernel upgrades (i.e. when you update the kernel, and boot the newly installed one, you'll have to do this over again). And again, this is why you placed the archive contents in /usr/local/src/hybrid-wl and changed the ownership of the directory and it's contents.