How to make pureos support more resolutions?

The best resolution for my computer is 1366x768, but I have no that selection, the largest that I can choose is 1024x768.
When I’m trying to add a resolution selection, it outputs error:
xrandr: Failed to get size of gamma for output default
How to make pureos support more resolution?
Meanwhile, I can’t reboot because I use it as a live CD. And it’s better for me to avoid installing non-free software.

What video card you use? It probably generic problem, not PureOS specific.

AMD Radeon HD 6370M
I wonder why Ututo supports many resolutions including 1366x768 for my computer, as an entirely free system too.

It have open-source driver. I don’t know, why it doesn’t work. Do you use wayland or Xorg?

I don’t know what wayland and Xorg are…
Oh…More problems…I gave up to install driver.:persevere:
I do believe there’s some way to change the resolution without installing driver. Because PureOS can display 1920x1080 on some computer without installing anything.

PureOS doesn’t include the proprietary firmware needed for AMD or NVIDIA GPUs. You’re probably running VESA, a generic GPU driver, rather than AMDGPU/radeonsi drivers.

Edit: Sorry, because you’re not running AMD drivers, that’s the reason for the lack of resolutions listed.

This videocard has open-source driver.

but also binary blob:
[root@dei ~]# ls -la /lib/firmware/radeon/ | wc
250 2243 15099

Maybe better to change linux distrubution to something, that allow to install binary blobs? You must be lucky to have system, that can work perfectly without proprietary blobs.

AMDGPU/radeonsi are free drivers that live in the kernel. But you need their proprietary firmware in order to use the GPU.

Thank you all, I understood.:sweat_smile:
Sorry for disturbing.

yes intel/AMD iGPUs/dGPUs are enabled through the MESA-linux-driver-stack but AMD ALSO offers a proprietary driver (for workstation GPUs) that MOST of the time works best with an LTS-linux-kernel.