> Have a look at the mails linked at 
> http://www.feyrer.de/NetBSD/blog.html#20050628_0233 for some ideas how
> 
> this works (manually).
> 

Thanks for all your replies. I finally got around the issue and wanted
to keep you posted.
My fundamental misunderstanding was, that I thought I have to create some
live filesystem on the cd, instead of simply using on of the install
kernels, which has already a ramdisk embedded into it.

Don't laught at me, but in fact I extracted the ramdisk from the
floppies, mounted it via vnconfig and copied everything over to my iso.
Even though this is somehow overkill, it still works very good. Well,
upto the point where sysinst wants to write into /tmp for a temporary
disktab :)
But I'm pretty sure I could have gotten around this very easy
with just creating some ramdisk for /tmp.

After that I was hit by an imaginary cluebat and finally used a correct
installation kernel. That worked without a hitch.

My conclusion is that cdboot might not be ready for prime time yet. But
with some will to try and straight things out it is already very, very
useful :)

Ralf