UART interrupt handler

Kira,

I think you're missing something here. A UART device driver is provided so that if you wish to send or receive characters over the uart you just use the standard C library calls putc, printf or any of those functions, for receiving you can use getc, scanf etc. see http://sources.redhat.com/newlib/libc.html (http://sources.redhat.com/newlib/libc.html) for the documentation.

You should not really be using the functions in the uart driver directly, unless you wish to re-write the driver, if so why?