Boot problems after upgrade

Hello!

I'm definitely missing something and some good advises are needed.

I have a running 7248 box (Model: IBM PPS Model 7248 (E))
Everything works fine (current version is 1.6)

I downloaded new sources with cvs:

cvs co -r netbsd-1.6

I want to build something similar to freebsd's stable branch. That is I do not
need just-added features but only security fixes and tested improvements.

Ran ./build.sh in /usr/src and got no errors here. Did etcupdate with no
problems.

Now I need to build a new kernel. (I know that it's better to build a
new kernel before world but I don't think it matters here.)

I built the kernel with no errors (I already have a custom kernel for 1.6
since the one from boot floppy can not determine root partition).
After that I did

cp netbsd /tmp
cd /tmp
gzip -c netbsd > netbsd.gz
/usr/mdec/mkbootimage /usr/mdec/boot_com0 boot.img netbsd.gz
dd if=boot.img of=/dev/sd0d

After rebooting I have:

boot device: <unknown>
root on sd0a dumps on sd0b
init: not found
panic: no init
syncing disks... done
dumpsys: TBD
rebooting...

What have I missed?

Any help will be greatly appreciated.

-- 
Oleg Sharoiko.
Software and Network Engineer
Computer Center of Rostov State University.