Stupid question

[Hans <hans.ullrich@loop.de>]

Dear list, 

I am thinking of a solution of a problem. But I have an understanding problem, 
maybe you can give some background knowledge.

The problem: I have one harddrive, there are two linuces installed.

The partitions are as followed:

kali-linux: 1st primary -> /boot
                 2nd > /


debian    3rd primary -> /boot
               4th logical > /
	             > swap
                                > /home (encrypted)
                                > /usr (encrypted)
                                > /var (encrypted)


This is the structure, and as said before, only ONE drive.

Now my question: Is it possible to configure grub that way, that I can choose 
either kali or debian to boot?

What I might to know, please correct me:
Both are running different kernels. As far as I understood grub, I can set the 
root partition ( / ) with the UUID. This is an entry in grub.cfg and maybe in 
/etc/default/grub. 

But how can I tell grub, to use the kernel of the second /boot? 

I dunno, if it is possible at all, to get a dual boot, the way I want it. With 
a combination of Windows + Linux on one harddrive this is working, however, 
just because grub does not touch the windows bootloader (as fas as I know), 
and what of course is also working, if you got two harddrives, each with 
different linux. They all can be booted from one grub installation, of course.

Maybe I could find a solution, if I would have fully understood how grub is 
working, and what it is doing.

Any hints are welcome, and if this does never work at all, please drop me a 
line.

Best regards

Hans