Installing Broadcom BCM4312 802.11b/g on centos

Download wireless package from Broadcom
Untar the file hybrid-portsrc-x86_32_5_10_27_6.tar.gz (hybrid-portsrc-x86_64_5_10_27_6.tar.gz if you’re running on a 64-bit kernel) in its own folder:

# tar -xvzf hybrid-portsrc-x86_32_5_10_27_6.tar.gz

You should now see this in your directory listing:

hybrid-portsrc-x86_32_5_10_27_6.tar.gz
lib
Makefile
src

Need to compile now
Wait..........
Before u compile...
Something missing in code:---
Without adding the following headers the compiling process exits with error
don't worry have solution here.
Add the following line to the file
Open file src/include/typedefs.h and add there the line below at header

# vim src/include/typedefs.h

#define TYPEDEF_BOOL

      Don't exclude the hash before define. It has to be typed as such mentioned here

Now build the Loadable Kernel Module (LKM) like so:

# make -C /lib/modules/`uname -r`/build M=`pwd`

Of course, you need to make sure you have all the required kernel headers before building it. Once that’s done, your directory listing should look like this:

built-in.o
hybrid-portsrc-x86_32_5_10_27_6.tar.gz
lib
Makefile
modules.order
Module.symvers
src
wl.ko
wl.mod.c
wl.mod.o
wl.o

The magic file we need is wl.ko. Make sure you don’t have b43, b43legacy or b43xx loaded by running this:

# rmmod bcm43xx; rmmod b43; rmmod b43legacy

And for good measure remove ndiswrapper modules:

# rmmod ndiswrapper

Now load the module ieee80211_crypt_tkip:

# modprobe ieee80211_crypt_tkip

And finally load the wl.ko module:

# insmod wl.ko

Now if you do an ifconfig, you should see wlan0 right after your eth0 and lo devices.

Else try iwconfig 

Yippee-kay-yay! Test it out by scanning and connecting to a network. If it works, then you might want your module to load upon boot, which is something the Broadcom readme doesn’t touch on. Let me school you how.

Copy the wl.ko file to /lib/modules/2.6.26-1-686/kernel/net/wireless/

# cp wl.ko /lib/modules/2.6.26-1-686/kernel/net/wireless/

Create the module dependencies:

# depmod -a