[avr-gcc-list] stdio - how extensible?

[Larry Barello]

I am wrapping up a serial io sample for my rtos (www.barello.net/AvrX) and
as a final test I spun up two tasks, one attached to USART0 and one to
USART1 (mega128).  Well, duh, it didn't work since the second call to
fdevopen() (task 2) failed miserably.  I knew that, I am just sometimes
thick in the morning ;^)

So, the question is: what would it take to extend the current stdio facility
to allow N descriptors (rather than just stdout, stdin and stderr).
Obviously, for my sample I need four channels.  But, I bet others are
hanging extra serial ports off the chip (mega8's or SPI USARTs) and could
use channels beyond four.  Or is this already implemented and I just need to
RTFM?

A second question: is stdio written to be re-entrant?  I.e. No static data
(other than the file descriptor)? The first question is sort of moot if
stdio is not re-entrant (for me at least).

----
Larry Barello
www.barello.net