Building a "hello world" initramfs with User Mode Linux.

  - Grab above statically linked hello.c.  Put in initramfs with directory
     method.  Show it.  Put in initramfs with script method.  Wheee.

  - Build a statically linked busybox, run it as standalone shell.
    Now run it as standalone shell under UML with rdinit=

  - Transfer to new RFS (hostfs) with switch_root, by hand.