By default older Mac computer models have driver issues with the Broadcom Wi-Fi chip. Most instructions online (such as this one from the official Ubuntu docs @ https://help.ubuntu.com/community/Macmini5-1/Precise) suggest to use sudo apt-get and install these packages from the PPA.
BUT you don't have Internet so you can't use apt-get! Instead you can use a different computer to download the packages, then transfer them over.
In the instructions below, you will need to replace sid in the download URL's with the proper version of Debian your version of Ubuntu/Linux is using. To find which version you should use, you can view the chart at https://askubuntu.com/questions/445487/what-debian-version-are-the-different-ubuntu-versions-based-on#445496. If you're using jessie for example, then replace all sid with jessie in the links below.
- Download
b43-fwcutter@ https://packages.debian.org/sid/b43-fwcutter (replace "sid" in the URL as needed -- scroll down to "Download" section and choose based off your architecture, and then select a mirror/FTP link to download from on the next page that appears). - Download
firmware-b43-installer@ https://packages.debian.org/sid/firmware-b43-installer (repeat same note as above) - Download
webfs@ https://packages.debian.org/sid/webfs (repeat same note as above) - Download http://www.lwfinger.com/b43-firmware/broadcom-wl-5.100.138.tar.bz2 (e.g. using
wget http://www.lwfinger.com/b43-firmware/broadcom-wl-5.100.138.tar.bz2) - Save these downloaded files to flash storage and then insert flash storage into your Ubuntu/Linux machine.
- Copy the files from the flash storage to your Ubuntu/Linux machine's desktop.
- Open a terminal and run the command
echo '127.0.0.1 www.lwfinger.com' | sudo tee --append /etc/hosts - Run the command
sudo dpkg -i ~/Desktop/webfs.deb(replace webfs.deb with the webfs deb file name) - Run the command
sudo mkdir -p /var/www/b43-firmware - Run the command
sudo mv ~/Desktop/broadcom-wl-5.100.138.tar.bz2 /var/www/b43-firmware/ - Run the command
sudo sed -i -e 's/web_root="\/var\/www\/html"/web_root="\/var\/www"/' /etc/webfsd.conf - Run the command
sudo sed -i -e 's/web_port=""/web_port="80"/' /etc/webfsd.conf - Restart the web server
sudo /etc/init.d/webfs restart(you may need to usesudo systemctl restart webfsif your system usessystemd) - Run the command
sudo dpkg -i ~/Desktop/b43-fwcutter.deb(replace b43-fwcutter.deb with the b43-fwcutter deb file name) - Run the command
sudo dpkg -i ~/Desktop/firmware-b43-installer.deb(replace firmware-b43-installer.deb with the firmware-b43-installer deb file name) - Run the command
echo 'blacklist ndiswrapper' | sudo tee --append /etc/modprobe.d/blacklist.conf - Run the command
echo 'SUSPEND_MODULES="b43 bcma"' | sudo tee ---append /etc/pm/config.d/modules - Run
sudo rebootand then check if you can connect to Wi-Fi. - See https://help.ubuntu.com/community/MacBookPro8-2#Wireless for other instructions, such as enabling Sensors. Also see https://askubuntu.com/questions/334561/problems-with-broadcom-bcm4311-wireless-card-on-hp-pavillion-dv6000#667832 for reference.
- Remove
webfsand the temp dir by typingsudo apt-get remove -y webfsandsudo rm -rf /var/www/b43-firmware/on your Ubuntu/Linux machine afterwards.
No problem