Setup Banana Pi M2 Zero

First install firmware-ap6212-bpi package, then run the following command:

# cp /usr/lib/firmware/brcm/brcmfmac43430-sdio.AP6212.txt /usr/lib/firmware/brcm/brcmfmac43430-sdio.txt

Then reboot.

Now, you should have a network interface named wlan0. You can check this by running the following command:

$ ip link

Or even through kernel debug messages:

$ dmesg