I tried the installation the way @Miahi described.
First i burned the iso (asg-9.403-4.1.iso) to a dvd, after that i changed the serial console speed in the config file on the dvd (and burned it again).
I connected to the serial console with putty. Booted the apu with a keyboard and the external dvd drive attached.
Selected boot from the dvd drive and this happened:
After that the dvd drive stops spinning and nothing happens. No installation screen no nothing ...
The Keyboard inputs (Alt+F2 -> mount /dev/sdb1 /install -> Alt+F1) do noting. I selected the boot device with the connected keyboard so the keyboard should work.
Does anyone know a solution?