I have noticed several problems when using coreboot native graphics ("high resolution" linear framebuffer) with a resolution of 1024x768, on SeaBIOS + SeaVGABIOS:
- Boot menus (GRUB, Syslinux) look at a resolution of 640x480.
- I get a warning in Debian "graphical" installer "Undefined video mode number: 314", asking me to select a mode, if I select a resolution of 1024x768 it boots fine, if I don't, after 30 seconds, it crashes.
- When I use iPXE with SeaBIOS I can't get video on "text based installers" (which use ncurses, for example Debian text based installers).
- In iPXE I get video on other "graphical" installers (e.g. Debian graphical installer).
- I have noticed that in "video mode" it is able to change resolution to show a bootsplash (mode 0x144 on vgasrc/svgamodes.c) and then goes back to 640x480 on "text console".
- In iPXE the text display resolution is 1024x7480, however the menus are 640x480.
I don't know if its implementation is incomplete, or because of technical reasons SeaVGABIOS is unable to behave correctly without a proprietary VGA BIOS.
I think a first step might be to be able to force a minimum resolution in text and video modes.
So, my first question is: what is needed to force SeaBIOS/SeaVGABIOS to display a resolution of 1024x768 instead of 640x480 when in "text mode" and "video mode"?
And my second question is whether with some work the coreboot native graphics implementation could behave as good as (or close to) a proprietary VGA BIOS.