I've installed Kubuntu 18.04 in order to use my Radeon HD 7870 XT. I've used AMD Gpu Official driver, downloaded from AMD website.

The driver is amdgpu-pro-19.20-812932-ubuntu-18.04.

After using the command:

Code:
amdgpu-pro-install.sh --opencl=legacy
After installation I've got black screen with cursor. I can move it, but nothing else.


I've used nomodeset on GRUB startup command, but nothing.

On dmesg with the command:
Code:
dmesg | grep 'amd'
I obtain:

Code:
[    0.000000] Linux version 4.18.0-25-generic (buildd@lgw01-amd64-033) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #26~18.04.1-Ubuntu SMP Thu Jun 27 07:28:31 UTC 2019 (Ubuntu 4.18.0-25.26~18.04.1-generic 4.18.20)
[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.18.0-25-generic root=UUID=08eb4ae9-b64c-4c8e-aadd-1f4cb9028a91 ro radeon.si_support=0 radeon.cik_support=0 amdgpu.si_support=1 amdgpu.cik_support=1 amdgpu.dc=1 amdgpu.dpm=1 amdgpu.modeset=1 splash quiet nomodeset
 vt.handoff=1                                                                                                                                                                                                                                                                
[    0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.18.0-25-generic root=UUID=08eb4ae9-b64c-4c8e-aadd-1f4cb9028a91 ro radeon.si_support=0 radeon.cik_support=0 amdgpu.si_support=1 amdgpu.cik_support=1 amdgpu.dc=1 amdgpu.dpm=1 amdgpu.modeset=1 splash quiet no
modeset vt.handoff=1                                                                                                                                                                                                                                                         
[    1.596361] amdkcl: loading out-of-tree module taints kernel.
[    1.596390] amdkcl: module verification failed: signature and/or required key missing - tainting kernel
[    1.731327] amdgpu: unknown parameter 'modeset' ignored
[    1.731707] [drm:amdgpu_init [amdgpu]] *ERROR* VGACON disables amdgpu kernel modesetting.
[   31.363030] amdgpu: unknown parameter 'modeset' ignored
[   31.363456] [drm:amdgpu_init [amdgpu]] *ERROR* VGACON disables amdgpu kernel modesetting.
I've made a new installation (from 19.04 to 18.04) because many people says the AMD driver are compatible with 18.04, and not for 19.04. How can I use new driver and how can I use the kubuntu desktop?