Syslinux - Jun 2009 - Memdisk - handle arbitrary start addresses

To support AndyTim's work on El Torito Memdisk, I just checked in a
change that lets Memdisk load a bootstrap at (almost) any address.  In
particular, after allocating memory for the hooks near the top of the
memory it relocates the transient real-mode code to just below the
hooks, so that it can continue to work but is out of the way of any
fixed address anyone might want to put into low memory.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.