After building my own kernel (version 3.2-rc7) i had some problems with installing the driver for my WiFi card. The card i have in my laptop is the following: Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01). I tried to install the driver using the Additional drivers menu but when installing i got a message that the installation wasn’t possible and to check the jockey.log. In the log file i noticed that the card is “blacklisted” and after removing it from the blacklist.conf it still wouldn’t install.
So after some searching on the internet i found a way to install the firmware. To download and install the needed files open a terminal window (press Ctrl+Alt+T) and copy+paste the following lines:
cd ~/Downloads/
wget http://mirror2.openwrt.org/sources/broadcom-wl-4.150.10.5.tar.bz2
wget http://downloads.openwrt.org/sources/wl_apsta-3.130.20.0.o
When download extract the broadcom-wl-4.150.10.5.tar.bz2 file using the following command:
tar xfvj broadcom-wl-4.150.10.5.tar.bz2
To install the firmware:
sudo b43-fwcutter -w /lib/firmware wl_apsta-3.130.20.0.o
sudo b43-fwcutter --unsupported -w /lib/firmware broadcom-wl-4.150.10.5/driver/wl_apsta_mimo.o
It may take some time before the wireless networks are detected and in the worst case you need to reboot your system.
Source.
It worked thanks for your info and sharing with everyone.