Re: kernel goes dark on boot

[mlelstv%serpens.de@localhost (Michael van Elst)]

manu%netbsd.org@localhost (Emmanuel Dreyfus) writes:

>I suspect a mode problem. In the boot prompt, gop displays:
>*0: 1920x1080 BGRR pitch 1920 bpp 32
> 1: 640x480 BGRR pitch 640 bpp 32
> 2: 800x600 BGRR pitch 800 bpp 32
> 3: 1024x768 BGRR pitch 1024 bpp 32
> 4: 1280x1024 BGRR pitch 1280 bpp 32

>Trying gop [1-3] causes the screen to go dark. But the machine is not
>crashed, I can still type blindly gop 0 and get the display back.

That's not part of the kernel. The bootloader is an EFI application
and just talks to the firmware.

The list presented usually matches the VESA BIOS modes. In my experience
the manufacturers often do not care about this list as modern OSes just
take over the display. So you may find modes that do not work or you
miss modes that match the native display resolution.

When the NetBSD kernel boots and the display driver (usually DRM nowadays)
supports your graphics device, it will also take over the display. This
happens in about the middle of the autoconfig process.

Without DRM you are usually stuck with the configuration left from UEFI.