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. Oracle VM VirtualBox provides a configuration option to control the graphics resolution for both interfaces, making the difference mostly irrelevant for users.
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.