The concrete contribution of the research report here
    is the design and implementation of a fully compartmen-
    talized operating system, MINIX 3. To properly isolate
    faults, we have removed all drivers from the kernel and
    run them as separate, unprivileged user-mode processes,
    protected by the MMU hardware. Since all servers also
    run in user mode in our design, only a tiny microker-
    nel that does not contain any foreign, untrusted code is
    left in kernel mode. Each component has only the mini-
    mum privileges it needs in order to prevent failures from
    spreading. In our design, driver failures are no longer
    fatal and do not require rebooting the computer.