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Help! Can't enable custom screen resolutions for linux?

Posted: 7. May 2008, 09:51
by steeeve
I have a Fedora 9 Preview VM and OpenSolaris 05-2008 VM freshly installed in VirtualBox 1.6.0 for Mac OS X today. My problem is, in the gnome "change screen resolution" control panel, it only gives me three resolutions to choose from: 640x480, 800x600, and 1024x768. How do I enable a bigger custom resolution, specifically 1440x900 because that is the native resolution of my 15" MacBook Pro.

According to the VirtualBox user guide, it says:
9.5 Custom VESA resolutions
Apart from the standard VESA resolutions, the VirtualBox VESA BIOS allows you to
add up to 16 custom video modes which will be reported to the guest operating system.
When using Windows guests with the VirtualBox Guest Additions, a custom graphics driver will be used instead of the fallback VESA solution so this information does not
apply.
Additional video modes can be configured for each VM using the extra data facility.
The extra data key is called CustomVideoMode<x> with x being a number from 1 to
16. Please note that modes will be read from 1 until either the following number is not
defined or 16 is reached. The following example adds a video mode that corresponds
to the native display resolution of many notebook computers:
VBoxManage setextradata "Windows XP" \
"CustomVideoMode1" "1400x1050x16"
The VESA mode IDs for custom video modes start at 0x160. In order to use the
above defined custom video mode, the following command line has be supplied to
Linux:
vga = 0x200 | 0x160
vga = 864
For guest operating systems with VirtualBox Guest Additions, a custom video mode
can be set using the video mode hint feature.
This is what I put in the OS X terminal
alam-150-193:~ srgregson$ VBoxManage setextradata "Fedora 9 Preview" "CustomVideoMode1" "1440x900x24"

VirtualBox Command Line Management Interface Version 1.6.0
(C) 2005-2008 Sun Microsystems, Inc.
All rights reserved.

And as for the whole part of:
In order to use the
above defined custom video mode, the following command line has be supplied to
Linux:
vga = 0x200 | 0x160
vga = 864
Problem is, the bash terminal says that there is no such command.
So WHERE do I enter the VGA command into my linux installation?
Xorg.conf? The bootloader configuration? Or am I supposed to enter it in my host OS X somewhere? It's very confusing.

Help! Can somebody please give me step-by-step instructions on how to enable a custom screen resolution in my linux/solaris guest machines?


EDIT:
I tried adding the vga lines to my xorg.conf, left me with a broken x-server, but I fixed my config file so x-server boots again. x11 doesn't recognize what "vga" is.
I also tried adding the vga line into grub, which also doesn't acknowledge the "vga" command.
So, if the whole vga command deal doesn't work in bash, xorg.conf, or my grub boot options -- where does it work?

Posted: 7. May 2008, 17:32
by m@riposa
I only tried using Ubuntu 8.04, but as far as I know the resolution is automatically changed when you resize your VM window or when you go fullscreen. Of course the Guest Additions have to be installed correctly.

It should not be necessary to change any config file manually. At least it worked in Ubuntu after the installation of the Guest Additions.

This worked for me

Posted: 23. May 2008, 01:48
by jhart
On my MacBook Pro 15":
VboxManage setextradata "Fedora 9" "CustomVideoMode1" "1440x900x32"


(I think that your bit depth was wrong)

Posted: 3. Dec 2008, 14:15
by sandos
You put the vga= in /boot/grub/grub.conf normally.

Re: Help! Can't enable custom screen resolutions for linux?

Posted: 11. Jan 2009, 06:33
by evilbananas
In order to use the
above defined custom video mode, the following command line has be supplied to
Linux:
vga = 0x200 | 0x160
vga = 864
The vga lines are kernel parameters.

Re: Help! Can't enable custom screen resolutions for linux?

Posted: 28. Oct 2010, 16:21
by zazzo
Hi,

I have the same problem. While i succeded in setting a proper video mode for Win, i didn't as far as Linux is concerned. I would like to use 1024x768 or a little bigger(i set 1250x700 in Win, it is really good for my job), but i do not know how to add the vga=... command nor where. Can you help? I am new, so i need a step by step description.

Thanks for the help.

Re: Help! Can't enable custom screen resolutions for linux?

Posted: 29. Oct 2010, 01:35
by ChipMcK
perhaps. in the Linux Guests forum
A search therein on 'custom resolution' yields http://forums.virtualbox.org/viewtopic. ... resolution and others