More People have been trying to build a kernelimage (zImage) using the PR1.2 SDK sources for the N9 device.
So far without any (public) succes.
If anyone Can provide Info on how to build a booting image (my build Will not get past the Nokia logo, after the BSS (Big Scary Screen),
Please post here any input that Will help us build a booting kernel.

Thanks to Javispedro for his feedback.

This is my (preliminary) summ-up

apt-get install fiasco-gen
cd <extracted-kerne-dir>
Change the ./kernel/arch/arm/configs/rm581_defconfig
Do changes to C-sources directly in the kernel folders
dpkg-buildpackage
and the resulting zImage will be in ./debian/build/kernel/arch/arm/boot/zImage

You will need to flash first complete firmware image, and next the kernel image (NO reboot between)
flasher -F orgfirmware.bin -f
flasher -F orgfirmware.bin -k zImage --flash-only=kernel -f -R
(complete instructions are available here http://talk.maemo.org/showthread.php...complete+flash)

BE Aware that reflashing pr1.2 kernel brings some issues regarding software updates, you WILL need to complete a full flash before being able to do so, erasing all data on your phone.
Usual disclaimer re warranty and risk of a bricked phone does apply !