Backup dive torch sources. Summary:

    boot	bootloader for the backup dive torch, must be flashed first.
    lamp	actual backup dive torch application.
    upgrade	separate program for optical reprogramming. Uses "lamp.elf"
		from above "lamp" subdirectory.
    common	common sources, used via symlinks.

lamp/read-serial is a python program for reading the optical data sent
back by the yellow LED in the dive torch. The ioctl code could only
be made working by inspecting linux kernel source because it directly
translates to a system call without the usual POSIX polishing by glibc.
There are python libraries for this but I didn't want to use them.

The serial line used is actually an USB low voltage serial device soldered
to a photo transistor + 22k pull-up. The backup dive torch housing made
the optical signal too weak which was compensated again by adding a
simple amplifier.