As i marked above if you wish to play with pureos
- Super Grub2 Disk ← download super grub disk, burn it to separate drive
- use pureos live (not installer media) on second drive
- boot super-grub2-disk
- put pureos live media to usb, and select detect grub.cfg
- boot pureos
- you will get commandline as pureos will not able to start wayland/Xorg
- nano /etc/apt/sources.list , add line:
deb Index of /debian/ bullseye non-free - apt update
- apt install firmware-amd-graphics
- service gdm restart
or just use Debian 11 installation media , PureOS is just a stripped debian 11 , and PureOS specific packages you can just add to debian 