On 09/12/2021 14:31, Alex Deucher wrote: > [...] > Once the driver takes over, none of the pre-driver state is retained. > You'll need to load the driver in the new kernel to initialize the > displays. Note the efifb doesn't actually have the ability to program > any hardware, it just takes over the memory region that was used for > the pre-OS framebuffer and whatever display timing was set up by the > GOP driver prior to the OS loading. Once that OS driver has loaded > the area is gone and the display configuration may have changed. > Hi Christian and Alex, thanks for the clarifications! Is there any way to save/retain this state before amdgpu takes over? Would simpledrm be able to program the device again, to a working state? Finally, do you have any example of such a GOP driver (open source) so I can take a look? I tried to find something like that in Tianocore project, but didn't find anything that seemed useful for my issue. Thanks again!