En bref :
<code bash>nano /etc/apt/sources.list
#Ajouter "non-free" à la fin des lignes
maj
agi firmware-linux-nonfree
maj</code>

The default installation of Debian doesn’t include proprietary packages or drivers. So after a fresh install, you may experience a lack of hardware functionality because non-free firmware isn’t installed. It can however be changed, here’s how :
\\
Editer la Debian repository list pour ajouter le mot « non-free » à la fin de chaque ligne
<code bash>sudo nano /etc/apt/sources.list</code>

{{:linux:installation:debrep-1024x300-1.png?direct&800|}}

Then update :
<code bash>sudo apt-get update</code>

Now, the installation of non-free drivers/blobs will be supported. To install such firmware blobs :
<code bash>sudo apt-get install firmware-linux-nonfree</code>

{{:linux:installation:debrep2.png?direct&400}}

Reboot to apply the changes.

All done.