At Fri, 27 Mar 2015 11:22:01 -0700, lyndat3@your-mail.com wrote:
I'll start here -- because it is opensuse and kernel-related -- but don't know if this is the ultimately right place to ask.
I'm working on setting console video resolution on an opensuse 13.2 server.
I want 'hi-res' (to the extent possible), text-only display from grub menu, through completion of linux boot.
My eventual questions are
(1) why is 'efifb' used? it's supposed to be Mac-only
No. It's a generic fb used for EFI boot.
(2) how do I change 'efifb' resolution?
Not easy, and unlikely working. Forget about it. efifb simply takes over the resolution from the EFI boot loader.
(3) can nouveaufb replace efifb completely?
Only when you disable efifb in the kernel build configuration. then you'll have a blank screen for certain time from the boot up until nouveau fb gets initialized.
In GRUB2 config I am able to set the video resolution (in my case, to 1920x1080) only AFTER the handoff to 'nouveaudb'
Given
grep . /sys/class/drm/card*-*/modes | head -n 3 /sys/class/drm/card0-HDMI-A-1/modes:1920x1080 /sys/class/drm/card0-HDMI-A-1/modes:1680x1050 /sys/class/drm/card0-HDMI-A-1/modes:1280x1024
setting
GRUB_CMDLINE_LINUX="... video=HDMI-A-1:1920x1080@60"
works as intended.
This is a boot option for kernel. It's no configuration of grub2 itself.
But, from grub menu display up until that point, i.e. prior to the fb handoff, the display resolution used by 'efifb' is currently limited to 800x600.
Available EFI video modes are
grub> videoinfo List of supported video modes: Legend: mask/position=red/green/blue/reserved ... Adapter 'EFI GOP Driver': * 0x000 800 x 600 x 32 (3200) Direct color, mask: 8/8/8/8/ pos: 16/8/0/24 0x001 1024 x 768 x 32 (4096) Direct color, mask: 8/8/8/8/ pos: 16/8/0/24
So, the problem is here. If the EFI firmware can't support your preferred resolution, efifb also can't use it, obviously. Check more whether the resolution is really available. If yes, you can specify it in /etc/default/grub, e.g. via GRUB_GFXMODE. As default, grub2 tries to pick up the native resolution, and use 800x600 as a fallback.
According to
https://www.kernel.org/doc/Documentation/fb/efifb.txt
"... efifb is only for EFI booted Intel Macs. ..."
This is not a Mac, so why is the 'efifb' being used? Since this is post-grub2-menu, it seems something in the opensuse install/setup is possibly misidentifying the hardware.
Too old documentation, scratch that. Takashi -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org