Thank you Mentalist Traceur. I have to take closer look at this (after I come back from Peru month from now). I think I have required knowledge how to do it - thanks to http://al.robotfuzz.com/~al/maemo/u-boot/. Anyway It would be nice to have package in extra-devel with uboot: PK+nokia default kernel, or at least uboot package (those uboot-pr13 packages somehow don't work). Another thing came to mind, does anybody tried kexec to boot from nokia default kernel to PK ?