bugGNU GRUB - Bugs: bug #37707, Resolution change has no effect...


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bug #37707: Resolution change has no effect...

Submitted by:  Michael Heyns <beanaroo>
Submitted on:  Sat Nov 10 11:40:36 2012  
Category: BootingSeverity: Major
Priority: 5 - NormalItem Group: Software Error
Status: InvalidPrivacy: Public
Assigned to: NoneOriginator Name: 
Open/Closed: ClosedRelease: 
Release: otherReproducibility: Every Time
Planned Release: None

(Jump to the original submission Jump to the original submission)

Sun Nov 3 05:11:26 2013, comment #7:

Some computers have only very limited number of modes supported in EFI mode and hence you can't choose some of modes. The modes can be listed by "videoinfo" in GRUB shell. Closing as requests back at reporter stayed unanswered.

Vladimir Serbinenko <phcoder>
Project Administrator
Fri Jan 4 21:04:44 2013, comment #6:

@Andrei: your problem is very differnt from Michael's one. Please stop squatting his bug report. And your problem seems to be a purely documentation/comprehension one. It would be legitimate to have a separate bug report for documentation but in any case please don't continue discussing your problem in someone else's unrelated bugreport.

Vladimir Serbinenko <phcoder>
Project Administrator
Fri Jan 4 19:16:20 2013, comment #5:

Quote:"Which resolution do you mean? Looks like the original question was about resolution the GRUB is in. Is it so or do you mean the resolution in which Linux boots?"
The resolution of the initial grub screen is correctly controlled by gfxmode. I speak about the parameter which grub passes to the kernel and which determines the resolution during the boot process is not correctlt described in grub documentation. It should be video=...... parameter, not vga=.... or gfxmode=.... or vbemode=... That is what I target.
The post, which is linked below, makes a difference between 16 bit and 32 bit boot protocole. Resolution is passed to the kernel with different options and it seems that the documentation of grub is treating just the 16 bit protocole.
I guess that is why the problem is observed only on some CPU and is not present on others.
I wonder how to check if my boot protocole is 16 or 32 bit.

Andrei <andrewa>
Fri Jan 4 00:13:31 2013, comment #4:

Where did you get the line " Mode 0x037f: 1600x900 (+6400), 24 bits " from? It looks more like a BIOS video mode info. The modes available in EFI and BIOS may differ.

Vladimir Serbinenko <phcoder>
Project Administrator
Thu Jan 3 23:45:22 2013, comment #3:

This is only regarding the grub2 boot menu.

I have noticed the problem only exists on my one laptop (Lenovo G780) and only if EFI/GPT is in effect.

I have have tried multiple reformats with multiple distributions of Ubuntu and Fedora. Using the same configuration with non-EFI installs or on other computers has desired effect.

I wish I knew more about how to dysect the problem.

Michael Heyns <beanaroo>
Thu Jan 3 22:48:52 2013, comment #2:

Which resolution do you mean? Looks like the original question was about resolution the GRUB is in. Is it so or do you mean the resolution in which Linux boots?

Vladimir Serbinenko <phcoder>
Project Administrator
Wed Dec 26 18:57:03 2012, comment #1:

I had the same problem. It is described in detail in the following post http://www.fclose.com/b/linux/2218/configuration-of-linux-kernel-video-mode/?view_comment=true#comment-3499 where today this guy offered a working solution for 32-bit boot protocole.
In short: gfxmode commands in grub influence just the grub menu and the initial few seconds of the boot process. To complete the boot process with the desired screen resolution, it should be passed to the kernel with video=...... parameter, not with vga=.... parameter. gfxmode=.... and vbemode=... suggested in arch linux posts also have no effect).
I consider this a fault in the documentation rather than a bug.
A few glitches still remain:
- while switching users the display resolution changes to a different value than the one set with video=... parameter. In my case I set video=800x600-32 and switch user screen is shown with 1024*768.
- same discrepancy is observed immediately after the first boot completes just before autolog on user screen comes - the mouse pointer is shown for a few swconds with 1024*768 resolution.
I guess that during some phases the display resolution is controlled in a different way . . .

Andrei <andrewa>
Sat Nov 10 11:40:36 2012, original submission:

Not sure if this is somehow related to bug #37664

Mode 0x037f: 1600x900 (+6400), 24 bits

Using Grub-customizer and manually editing configuration files have absolutely no effect on resolution.

Background and colours can be changed.

Baffled by why this could be happening.

Ubuntu 12.10 x64 - 3.5.0-17-generic
Grub2 version: 2.00-7ubuntu11
Lenovo G780 - i7-3612QM - Nvidia GT630M (Optimus mode)

No idea what to look for in which log files or how to debug.

Michael Heyns <beanaroo>


Attached Files
file #26904:  grub added by beanaroo (1kB - application/octet-stream - Attached /etc/default/grub & /boot/grub/grub.cfg)
file #26905:  grub.cfg added by beanaroo (7kB - application/octet-stream - Attached /etc/default/grub & /boot/grub/grub.cfg)


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -unavailable- added by phcoder (Posted a comment)
  • -unavailable- added by andrewa (Posted a comment)
  • -unavailable- added by beanaroo (Submitted the item)
  • -unavailable- added by beanaroo

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    Follow 5 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Sun Nov 3 05:11:26 2013phcoderStatusNone=>Invalid
    Sat Nov 10 11:40:36 2012beanarooAttached File-=>Added grub, #26904
      Attached File-=>Added grub.cfg, #26905
      Carbon-Copy-=>Added beanaroo

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