EFI provides two distinct video interfaces: GOP (Graphics Output
Protocol) and UGA (Universal Graphics Adapter). Modern OSes,
such as Mac OS X, generally use GOP, while some older ones still
use UGA.
The default resolution is 1024x768. To select a graphics
resolution for EFI, use the following
VBoxManage setextradata "VM name" VBoxInternal2/EfiGraphicsResolution HxV
Determine the horizontal resolution H and the vertical resolution V from the following list of default resolutions:
640x480, 32bpp, 4:3
800x600, 32bpp, 4:3
1024x768, 32bpp, 4:3
1152x864, 32bpp, 4:3
1280x720, 32bpp, 16:9
1280x800, 32bpp, 16:10
1280x1024, 32bpp, 5:4
1400x1050, 32bpp, 4:3
1440x900, 32bpp, 16:10
1600x900, 32bpp, 16:9
1600x1200, 32bpp, 4:3
1680x1050, 32bpp, 16:10
1920x1080, 32bpp, 16:9
1920x1200, 32bpp, 16:10
2048x1080, 32bpp, 19:10
2160x1440, 32bpp, 3:2
2304x1440, 32bpp, 16:10
2560x1440, 32bpp, 16:9
2560x1600, 32bpp, 16:10
2880x1800, 32bpp, 16:10
3200x1800, 32bpp, 16:9
3200x2048, 32bpp, 16:10
3840x2160, 32bpp, 16:9
3840x2400, 32bpp, 16:10
4096x2160, 32bpp, 19:10
4096x3072, 32bpp, 4:3
5120x2880, 32bpp, 16:9
5120x3200, 32bpp, 16:10
6400x4096, 32bpp, 16:10
6400x4800, 32bpp, 4:3
7680x4320, 32bpp, 16:9
If this list of default resolution does not cover your needs,
see
The EFI default video resolution settings can only be changed when the VM is powered off.