booting without filesystem

[Anselm Strauss]

hi,

i was looking for a possibility to boot grub 2 without needing a filesystem 
with grub files somewhere on the disk. i know i can make such an image with 
grub-mkrescue, but it generates an iso which, as far as i know, is not bootable 
directly from disk. even when i have created a disk bootable image with 
grub-mkimage, how do i get the pc bios to boot this from a gpt formatted disk? 
is there some standard mbr bootcode i can install that just locates the bios 
boot partition in gpt and chain loads it, so i could just write the grub image 
to this partition?

it may look a bit strange why to not just put the files on some filesystem on 
disk which you will have anyway if you are going to install some operating 
system. but my reason for this is that the installation is automated and 
updating is a lot easier if i just have to write a new image, instead of 
updating files on a filesystem, which would not be done automatically by a 
package manager. also i had a lot of trouble with grub-install depending on 
what environment i executed it in. writing some mbr bootcode and the grub image 
to the boot partition looks a lot easier to me.

thanks,
anselm