install g++-multilib

download from here http://os.inf.tu-dresden.de/L4Re/download.html put l4re_snapshot instead of just l4re

build the l4 http://os.inf.tu-dresden.de/L4Re/build.html

build the fiasco http://os.inf.tu-dresden.de/fiasco/build.html

at the “make grub2iso E=hello MODULE_SEARCH_PATH=/path/to/fiasco-build-dir” put the “O=” as well

for emulation >sudo apt-get install xorisso qemu qemulator

testing the fiasco L4 > qemu-system-x86_64 -cdrom ~/f/src/l4/l4build/images/hello.iso

i will try to build again with ubuntu 12.04 64bit, i ve tried on 32bit and seems to be no problem.