l4linux shutdown cleanup

Dear all,

I would like to perform some cleanup operations after l4linux shuts down..such as zero out all the memory it used and re-encrypt the original vmlinux image. I would like to know how I could do this from sigma0 preferably or even in the fiasco kernel. Could anyone point me to where the clean up procedure (release of resources) occurs once l4linux shuts down?

Thanks,
Ramya