Framebuffer

The framebuffer's original function is as a video RAM cache to allow more flexibility to (older) video cards. Many newer cards come with framebuffers on board, which are often already compatible with many operating systems. Enabling framebuffer support in the Linux kernel will often cause graphical artifacts or black screen displays. For most newer cards, this option should not be selected when using the LiveDVD.

Checking the Console Driver
On the boot media fb0 - is the primary display. The console will appear here. frame buffer device tells that is indeed a framebuffer console. fb0: amdgpudrmfb tells that the driver in use is the kernels amdgpu drm fb framebuffer driver. That's included with the kernel amdgpu driver. No other framebuffer drivers are strictly required but see early console drivers below.

Other video cards will show something similar.

nVidia users may find that the above grep returns nouveaufb. It is not possible to use the kernel nouveau driver and nvidia-drivers concurrently. Only the early framebuffer drivers may be selected.

The Kernel Selection
Most of the the kernel framebuffer options are for use with hardware over 20 years old. These options almost always interfere with modern Direct Render Manager (DRM) provided framebuffers as both will attempt to configure the hardware and neither will work.

DRM Framebuffer Drivers
For everyone except nvidia-drivers users

On the Graphics support menu choose <*> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) ---> [*]  Enable legacy fbdev support for your modesetting driver (100)  Overallocation of the fbdev buffer

Back on the Graphics support menu, choose your DRM driver. Xorg will use this later.

The author uses AMDGPU  AMD GPU [ ]  Enable amdgpu support for SI parts [ ]  Enable amdgpu support for CIK parts [*]  Always enable userptr write support ACP (Audio CoProcessor) Configuration ---> Display Engine Configuration ---> [ ]  HSA kernel driver for AMD GPU devices < > Nouveau (NVIDIA) cards < > Intel 8xx/9xx/G3x/G4x/HD Graphics < > Virtual GEM provider < > Virtual KMS (EXPERIMENTAL)│ < > DRM driver for VMware Virtual GPU < > Intel GMA500/600/3600/3650 KMS Framebuffer There are very few uses for the Virtual drivers.

will install the required firmware.

Early Framebuffer Drivers
Early because the DRM Framebuffer drivers typically require firmware to be loaded which implies that they are often build an loadable modules. They therefore start sometime later than built in drivers. This mean that the early console messages are lost as the console is blank until the DRM driver is initalised.

Only four Early Framebuffer Drivers are safe for modern hardware < >  VGA 16-color graphics support [ ]  VESA VGA graphics support [ ]  EFI-based Framebuffer Support < >  Simple framebuffer support Its safe to choose them all as none of then try to control the hardware. The kernel will pick and choose at boot time.

External resources

 * https://forums.gentoo.org/viewtopic-p-8111658.html#8111658