Resolution for Grub menu

[Crischi94]

Hello there,

I have a Linux Mint 17.3 (Rafaela, I think?) Cinnamon x64 installed on my Windows 10 Edu x64 host.
The only reason for having this VM is to test the configuration of the Grub Boot Menu. But to translate the configuration to my real system after it is complete I need the right display resolution in my virtual Grub Menu.
In the /etc/default/grub I edited the GRUB_GFXMODE to my display resolution. But that had no effect.
After that I checked the possible resolutions in Grub with videoinfo. But there were no 16:9 resolutions listet. My real monitor has 1920x1080x32. If I change the setting to a resolution out of the list, it works fine, but it never fits my screen.

The weird thing ist, that the Grub AND the login screen are 640x480. After logging in the resolution automatically changes to 1920x1080. When I log out it will bei in 640x480 again.
The Guest Additions are installed by default with Linux Mint.

How can I fit the Grub Boot Menu to my needed resolution?

Thanks for you support!
Kind regards
Crischi94

[Perryg]

This actually does not have a lot to do with VirtualBox. grub boot is before any graphics mode is enabled so you need to use framebuffers to set the required resolution. IE: adding vga=*** to the boot parameter.

[Crischi94]

Thanks Perryg for you really quick answer!

My problem reading your answer is, that I installed Linux three times in my life. The first both ones I forgot after installation and after two years having them not used I deleted them.
The third installation is this, where I'm more active. So I don't really know very well about Linux in general.

Could you please explain this a little bit deeper for me?

Thanks and kind regards
Crischi94

[Perryg]

First determine the resolution you want and then look up the vga mode you need. Here is one of many you can find http://pierre.baudu.in/other/grub.vga.modes.html

Then you can test this by booting and selecting to edit the boot sequence and add the vga=*** and see if it does what you want. Then if it is you edit the grub control file and add the vga=*** to the proper place which should be ( see screenshot ) GRUB_CMDLINE_LINUX_DEFAULT=. don't forget to run update-grub before you reboot.

grub_framebuffer.png (14.99 KiB) Viewed 3571 times