Grub2 Multiboot2 video mode

[dschatz]

Where can I find documentation on Grub's implementation of multiboot2? It doesn't follow the latest specifications and I've tried to query grub for video information but it doesn't seem to provide what I would expect (framebuffer_type is not set to any of the values it should be). I really just want to know what video mode (if any) my kernel is in when it gets handed control from grub. I could do this by accessing the bios data area but I suspect grub provides this information.

[gerryg400]

As Berkus said, you must follow the source.

Grub2 does NOT follow the multiboot 2 spec.

[lemonyii]

yeah, see "grub\multiboot2.h" and you'll find the header is the same as multiboot1, and few differences. I had ever been crazy because of this.
but my experience is, do not expected anything from grub except loading your kernel and memory information, because anyghing else is not ensured.(though so is memory information, but much better).
as you are still in 32bit mode and you have to do many things, what about intergrate your previous bootloader as the bootstrap in kernel? that what i did. it provides me with vesa settings, 64bit mode settings, anything except loading my kernel and memory information.
good luck!