add attribute weak to UART receivinterrupt handler

i've been wanting to encapsulate serial handling (and have packets processed without needing to do polling) for some XBee packet handling libraries -- this would be greatly simplified if the USART RECV signal handler was set up as a weak symbol, so I could install my own signal handler... i imagine this would also be useful for others doing similar custom processing of serial data outside of the normal Arduino serial libs... it may be useful to do this with other signal handlers as well.


--- orig-arduino/wiring_serial.c 2008-02-23 14:37:35.000000000 -0500
+++ arduino/wiring_serial.c 2007-08-06 19:20:00.000000000 -0400
@@ -105,10 +105,8 @@

#if defined(AVR_ATmega168)
+SIGNAL(SIG_USART_RECV) attribute((weak));
+SIGNAL(SIG_UART_RECV) attribute((weak));

I would also like to be able to re-define signal handlers. For example tweaking the clock overflow interrupt to be more intelligent. Right now I have to hack into the wiring core code and it's messy. :frowning:

Thanks for the idea,