[syslinux] interacting with UART

[Ady]

> 1) menu.c32 in serial mode.  Using the shortcut keys to select a label
> then providing an <enter> keystroke, it'll work.  Set DEFAULT or
> ONTIMEOUT, TIMEOUT, SERIAL, CONSOLE, and create LABELs with MENU
> LABELs containing '^' for the shortcuts.
 
With a little bit of creativity in the configuration file, you could 
also avoid using menu.c32.

The LABELs can be one-character-long each. The LABELs corresponding to 
DEFAULT, ONTIMEOUT and ONERROR could optionally be longer, as:
_ for DEFAULT, press ENTER;
_ for ONTIMEOUT, it is activated by not pressing anything until the 
TIMEOUT is triggered;
_ for ONERROR, trigger a relevant erroneous (non-existent) LABEL, with 
the caveat that it must not affect the resulting command (perhaps a 
space or underscore character(s) plus [enter]? I haven't tried it).

Of course, those LABELs could also be one-character-long anyway.

The other LABELs could be one-character-long, avoiding the need for 
using menu.c32 just for the "shortcut".

Then, we also have the [ctrl-] combinations for msg ("DISPLAY") help 
files (which also have a corresponding output mode).

If there is anything that doesn't work as "expected", feedback is very 
helpful and appreciated; so are patches / contributions.

Regards,
Ady.