Disabling Wifi and Bluetooth in RPi 4

I started to use my raspberry pi 4 not long ago. As I use Debian the obvious choise was to flash the Raspberry Pi Debian image into the SD card.

Now, as I’m planning connect it with a ethernet cable, I decided to disable the radio antennas. I tried to ways to achieve that.

Disabling them using config.txt

To do that you only need to:

1. Create (or modify) /etc/default/raspi-firmware-custom with:

   # Disable bluetooth and wifi
   dtoverlay=disable-wifi
   dtoverlay=disable-bt
   

2. Run update-initramfs -u -k all

   This basically will update the /boot/firmware/config.txt with the above lines.

Remember that raspberry pi uses a config.txt file to modify the settings you would expect in the BIOS/UEFI in a normal PC.

Now, after I restarted it, I noticed it didn’t work. Checking /etc/default/raspi-firmware I read Maybe not all options are supported..

So, I proceed to disable the modules.

Disabling the wifi/bt modules

1. Create this file /etc/modprobe.d/raspi-blacklist.conf and add:

    # Disable wifi
    blacklist brcmfmac
    blacklist brcmutil
   
    # Disable bluetooth
    blacklist hci_uart
    blacklist btbcm
    blacklist btintel
    blacklist rfcom
    blacklist btqca
    blacklist btsdio
    blacklist bluetooth
   

2. Restart

This time it worked! \o/.