...

(1) why is 'efifb' used? it's supposed to be Mac-only

No. It's a generic fb used for EFI boot. ...

...

https://www.kernel.org/doc/Documentation/fb/efifb.txt

Too old documentation, scratch that.

Sigh. Thanks.

...

(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.

I conflated the two. I understand now that they're separate items.

...

(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.

Okay. Not a useful state.

...

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.

Point taken.

...

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.

The result here is insensitive to GRUB_GFXMODE, despite what I see wih 'videoinfo'. Then, consistent with 800x600 as a fallback. All clear, now. My boot-console's close enough to my goal now. And, I end up at login prompt in reasonable type size and full screen real-estate. Makes emergency mode more manageable. Add to that serial console, and I'm all set. Thanks. Next, Xen ... LT -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org

At Sat, 28 Mar 2015 07:57:01 +0300, Andrei Borzenkov wrote:

В Fri, 27 Mar 2015 21:49:21 +0100 Takashi Iwai пишет:

...

...

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.

I'd still expect it to select 1024x768 here; normally grub prefers the best possible resolution if told to autodetect. It may make sense to open bug report to investigate why it is stuck on 800x600.

This must be a fallback when the BIOS firmware doesn't give the preferred resolution. 800x600 is chosen because of safety reason. So, blame BIOS instead :) Takashi -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org

At Sat, 28 Mar 2015 12:25:04 +0300, Andrei Borzenkov wrote:

В Sat, 28 Mar 2015 08:42:47 +0100 Takashi Iwai пишет:

...

At Sat, 28 Mar 2015 07:57:01 +0300, Andrei Borzenkov wrote:

...

В Fri, 27 Mar 2015 21:49:21 +0100 Takashi Iwai пишет:

...

...

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.

I'd still expect it to select 1024x768 here; normally grub prefers the best possible resolution if told to autodetect. It may make sense to open bug report to investigate why it is stuck on 800x600.

This must be a fallback when the BIOS firmware doesn't give the preferred resolution. 800x600 is chosen because of safety reason.

Nope, grub does not fall back to 800x600 on its own. If requested resolution cannot be set, it would fail to load gfxterm.

This could happen if resolution is not explicitly requested and firmware returns EDID with preferred resolution 800x600 or does not return anything at all - then grub would use 800x600 indeed.

I meant this behavior of efi_gop as fallback. Takashi -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org