AMD Radeon 6490M

[LuKaRo <lists@lrose.de>]

Hi everyone,

I just installed Debian Buster with KDE Plasma on a notebook that has an AMD Radeon 6490M and an Intel HD Graphics 3000 installed. The installation (text-based) worked fine, however, after rebooting, I just get a tty, X won't start. When checking dmesg for any errors, I found:

[drm:radeon_pci_probe [radeon]] *ERROR* radeon kernel modesetting for R600 or later requires firmware installed
    Xorg furthermore listed errors like this:
[    14.666] (II) FBDEV(4): using default device
[    14.682] (II) modeset(G0): using drv /dev/dri/card0
[    14.682] (EE) Screen 0 deleted because of no matching config section.
[    14.682] (II) UnloadModule: "radeon"
[    14.682] (EE) Screen 0 deleted because of no matching config section.
[    14.682] (II) UnloadModule: "modesetting"
[    14.682] (EE) Screen 1 deleted because of no matching config section.
[    14.682] (II) UnloadModule: "fbdev"
[    14.682] (II) UnloadSubModule: "fbdevhw"
[    14.682] (EE) 
Fatal server error:
[    14.683] (EE) Cannot run in framebuffer mode. Please specify busIDs        for all framebuffer devices

So I searched the internet and found several sources that recommended installation of

firmware-amd-graphics

from non-free. I installed that package, but afterwards the system won't boot at all - it only displays "loading initial ramdisk" and then the screen goes black.

Any ideas on how to get graphics output on that machine? I don't even need the radeon graphics, the integrated Intel graphics would be okay for a start as well. My full Xorg.0.log and my dmesg are attached here and here.. Thanks a lot in advance for any ideas!

Kind regards,
LuKaRo