This method should work on any Linux distribution that supports this firmware.
This is an offline method; you will need a second computer to copy the zip archive specified and moved to the MacBook Pro 2012 or use Ethernet (with adapter) to download this archive.
The wireless chip is from Broadcom, and the firmware version is B43.
Download the zip archive by clicking this link.
Copy the file on a flash drive and move it into a folder on the MacBook Pro,
Now extract the archive.
Open Terminal and enter the commands specified below.
Let’s create the directory for the firmware.
sudo mkdir /lib/firmware/b43
Copy the firmware files into the folder, this command example assumes you copied and extracted the files on Desktop, if you choose any other location change the location after
cp to the correct path.
sudo cp Desktop/b43/* /lib/firmware/b43
After successfully copying the files it’s time to do some
Enter the two commands specified below.
sudo modprobe -rv b43
sudo modprobe -v b43
Now you should see the wireless applet detecting signal and the Wi-Fi option working in the network manager or gnome settings. If not, you might have to reboot.
Have a good day!