How does grub locate grub.cfg

[Roger James]

Help!

What is the algorithm (if any) used by grub2 to locate the grub.cfg 
file? Are there any hints encoded into the image files by grub-mkimage 
and grub-setup, for example the --prefix parameter to grub-mkimage and 
the -root-device parameter passed to grub-setup. I am interesting in 
finding information on this before embarking on an installation which 
may end up with two different /boot/grub/grub.cfg files in different 
paritions on different drives!

I have not be able to find this information in any documentation, and 
one quick look at the source tree led me to ask here first!

As an aside, is there such a thing as a grub image analyser that can 
take a grub boot installation/image and print out what it contains?

Thanks,

Roger