Actually there seams to exsist some very old patches for this http://lists.denx.de/pipermail/u-boot/2006-September/016960.html Here a paper quite exact what I am after: http://elinux.org/images/2/28/Trusted_Boot_Loader.pdf Is there any toughts on integating this in trunk or should I try to merge this patch with the git trunk of my own?