soren@t.dk said:
> How about an MD5 of the kernel image? 

Some ID would be good, but a checksum of the image is not easy:
-the bootcode would have to calculate it, which causes bloat
-the started kernel must check it, but probably can't do this
 before it modified some of it's global variables

It it very easy for a user program to check whether the
running kernel is what it assumes: compare `uname -v` to
`strings /netbsd | grep NetBSD` or so, thus I don't thing
it is worth to spend bootloader or kernel code for it.

best regards
Matthias