Graphics
The goal of this documentation is doing linear graphics without having to
talk the BIOS via the VBE interface. Preferedly with as few as possible
mode switches (switchless boot).
Definitions
GRUB = Bootloader on x86-x86_64
EFI= Extensible Firmware Interface
VESA = Video Electronics Standards Association
VGA = Video graphics adaptor
VBE = VESA BIOS Extensions.
stdvga = QEMU standard vga device
BGA = Bochs Graphics Adaptor
QXL = Paravirtualized framebuffer device, used with spice protocol.
Asking GRUB
The easist is if you are using GRUB you can just ask it for a linear mode. Setting width and height to 0 will leave the EFI/BIOS mode in place (if it is linear), giving you switchless.
Virtual graphics
There are several virtual grahpics card, none exhaustive list: VMware SVGA,
stdvga, BGA, QXL. Qemu supports all of these tho the VMware SVGA
support is very limited.
Luckily for us stdvga is backwards compatible with BGA.
Real hardware
This is hard :(