I have compiled and build a grub.efi and managed to bless the usb disk making it visible and bootable on my MacBook Pro.
Everything looks fine. I can load my kernel with the "multiboot" command. When i try to boot the kernel it says "Warning: no console will be available. Error: could not detect mode" or something..
This i suspect is due to that EFI is using EFI graphics and that plain old bios / videomode / output will not be available..
That should be no problem for my plan is to create a simple console for EFI fb...
But.. I just wonder.. What mode is the CPU in when the image is executed? Is it in 32 or 64? I guess in the multiboot specs it says 32bit pmode with idendity mapped linear address space.
Anyone have any experience or information on this?? If there is interrest i could make a wiki page with details how to compile the EFI version of grub and how to actually get it booting.
Update;
I created some EFI info on Grub in the wiki..
http://wiki.osdev.org/GRUB#Grub_for_EFI
Update2;
Looks like i found an answer: http://www.gnu.org/software/grub/manual ... rnels.html
Shows "multiboot" is available on 64bit EFI.. So that should mean that a normal 32 bit multiboot kernel would run like normal.. That needs to be tested out. Since no screen output is possible atm i think a reboot or something like that would be the best evidence that its working.. Since now its just sitting there.. Hopefully working, but not sure..
best regards
Thomas