The serial_transfer loader, as long as the target program voluntarily
terminates itself at some point, is able to load multiple programs
consecutively without requiring a physical power cycle to reload the
transfer program from CD.
The current example.mk juggles between two different "memory layouts",
one for "burn to a physical CD" and another for "load via serial
cable". Because the serial_transfer program now relocates itself to
the end of system memory, this means the 0x8c010000 area is now usable
by programs that are loaded by serial_transfer.
