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beanaroo
Asked: 2012-10-27 15:49:58 +0800 CST

Why isn't Grub2 using custom resolution?

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I hope somebody can help me with this... Running Ubuntu 12.10 GNOME Remix

I am trying to get Grub2 to use a resolution of 1600x900...

I have checked vbeinfo and hwinfo --framebuffer which both provide:

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

This resolution has worked on previous Ubuntu and Fedora installs.

Why is it not taking effect?? I have tried different resolutions... Backgrounds and font colours are changeable.

Thank you for your insight.

boot

4 Answers

  1. When you set the mode, try to also include the bit depth in /etc/default/grub, e.g.:

    GRUB_GFXMODE=1600x900x24

    Also add this line:

    GRUB_GFXPAYLOAD_LINUX=keep

    Run sudo update-grub, reboot and let us know if it worked.

    • 3

  2. I think GRUB_GFXMODE gets ignored (or at least it was at some point ago). You can always try the traditional way with vga code

    1. First you install hwinfo:

      sudo apt-get install hwinfo

    2. Then you get the vgacode with hwinfo (preferred resolution, 24 bits):

      sudo hwinfo --framebuffer

      02: None 00.0: 11001 VESA Framebuffer
      [Created at bios.464]
      Unique ID: rdCR.ku_DuSHewh1
      Hardware Class: framebuffer
      Model: "Intel(R)Sandybridge Mobile Graphics Controller"
      Vendor: "Intel Corporation"
      Device: "Intel(R)Sandybridge Mobile Graphics Controller"
      SubVendor: "Intel(R)Sandybridge Mobile Graphics Chipset Accelerated VGA BIOS"
      SubDevice:
      Revision: "Hardware Version 0.0"
      Memory Size: 63 MB + 960 kB
      Memory Range: 0xd0000000-0xd3feffff (rw)
      Mode 0x0360: 1366x768 (+1408), 8 bits
      Mode 0x0361: 1366x768 (+2752), 16 bits
      Mode 0x0362: 1366x768 (+5504), 24 bits
      Mode 0x0363: 1600x900 (+1600), 8 bits
      Mode 0x0364: 1600x900 (+3200), 16 bits
      Mode 0x0365: 1600x900 (+6400), 24 bits
      Mode 0x0366: 1920x1080 (+1920), 8 bits
      Mode 0x0367: 1920x1080 (+3840), 16 bits
      Mode 0x0368: 1920x1080 (+7680), 24 bits
      Mode 0x0307: 1280x1024 (+1280), 8 bits
      Mode 0x031a: 1280x1024 (+2560), 16 bits
      Mode 0x031b: 1280x1024 (+5120), 24 bits
      Mode 0x0305: 1024x768 (+1024), 8 bits
      Mode 0x0317: 1024x768 (+2048), 16 bits
      Mode 0x0318: 1024x768 (+4096), 24 bits
      Mode 0x0312: 640x480 (+2560), 24 bits
      Mode 0x0314: 800x600 (+1600), 16 bits
      Mode 0x0315: 800x600 (+3200), 24 bits
      Mode 0x0301: 640x480 (+640), 8 bits
      Mode 0x0303: 800x600 (+832), 8 bits
      Mode 0x0311: 640x480 (+1280), 16 bits
      Config Status: cfg=new, avail=yes, need=no, active=unknown

    3. You edit a line in your /etc/default/grub (or you just use grub-customizer) to include vga=0x0365 or vga=891 (0x365 is 869) :

      sudo gedit /etc/default/grub

      ...
      GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vga=891"
      ...

    4. You update the grub configuration:

      sudo update-grub

    5. Reboot and let us know what happened

    • 3

  3. Just resolved the same issue for me. Here what I've done:

    Disabled previous framebuffer (was vga16fb for me) and enabled uvesafb:

    /etc/modprobe.d/blacklist-framebuffer.conf :

    ...
blacklist vga16fb

    You can find what framebuffer is currently is use using lsmod | grep fb command.

    /etc/modprobe.d/framebuffer.conf :

    options uvesafb mode_option=1680x1050-24 mtrr=3 scroll=ywrap

    /etc/modules :

    ...
uvesafb

    The next step is to put uvesafb into initrd image.

    /etc/initramfs-tools/modules :

    ...
uvesafb mode_option=1680x1050-24 mtrr=3 scroll=ywrap

    Re-create initrd: sudo update-initramfs -u

    For now, the hi-res console should be available after boot. Next task is to turn grub2 into hi-res mode. For some reasons, several important options was missing into my grub config file, so I added them into /etc/default/grub:

    GRUB_VIDEO_BACKEND="vbe"
GRUB_TERMINAL_OUTPUT="gfxterm"
GRUB_GFXMODE="1680x1050x24"
GRUB_GFXPAYLOAD_LINUX="1680x1050x24"

    I'm not sure about next section, it may be not nesessary, but here what I've done to /etc/grub.d/00_header :

    Almost at the top of the file there is a number of if [ "x${GRUB_... fallback operators. I've added two more:

    if [ "x${GRUB_GFXMODE}" = "x" ] ; then GRUB_GFXMODE=1680x1050x24 ; fi
if [ "x${GRUB_GFXPAYLOAD_LINUX}" = "x" ] ; then GRUB_GFXPAYLOAD_LINUX=1680x1050x24 ; fi

    Now find the text set gfxmode=${GRUB_GFXMODE} in that file, and insert the following code as the next line:

    set gfxpayload=${GRUB_GFXPAYLOAD_LINUX}

    Again, I'm not sure if it nesessary for the latest grub2 (I have 1.98) Now update grub config file:

    sudo update-grub2

    and everything should be working.

    • 0

  4. In my case there was other configuration file besides /etc/default/grub, /etc/default/grub.d/kali-themes.cfg (as you imagine it is Kali Linux, debian derivative, just like Ubuntu).

    It had a line GRUB_GFXMODE="auto,1280x720,1280x800" that has been breaking everything. Now, deleteing it and doing update-grub fixed it on my real system.

    Just note that some resolutions do not work with auto! They are some nonstandard ones, like 1150xsomething (on vmware, for example). You need to explicitly tell grub that in GRUB_GFXMODE.

    Also note that in vmware that will never work because the GOP UEFI driver in Vmware does not support higher resolutions (see videoinfo command in uefi-grub command line).

    Also note that only UEFI booting without CSM supports high resolutions in nvidia GPUs, BIOS VESA extensions are not supported, as nvidia still did not write that driver, but with UEFI it is not needed anymore.

    Also note that even though in grub there can be 60 fps, there is no way to set 120 Hz or 100 Hz (at least IMHO), and that will mean non smooth switch to Linux Kernel screen, that is why you may want to directly boot kernel without grub. Read about EFISTUB kernel mode. It also will permit Secure Boot in many cases of signed kernels that debian supports.

    • 0