Re: [avr-libc-dev] Re: printf in avr-libc

[Joerg Wunsch]

As Jörgen Birkler wrote:

> A LOT is rewritten from Alexander's version. I spent
> several hours with GCCv3.2 looking at the list file to
> minimise the code size. Tried different switch / if
> constructs, etc. I do not think that we need to start
> from scratch.

Assuming we could clarify the licensing issues without rewriting it
from BSD scratch, yes. :)

> I agree that putchar (used by printf) could be
> predefined by stdlib to output characters on the UART
> at 9600. If the programmer want's something else
> she/he simply define their own putchar function.

Well, actually not all of our supported devices have a UART.  Also,
UART speed depends on system clock, so an automatic implied
initialization is impossible anyway.

Thus, we need to leave this to the application programmer to first
call something comparable to fopen().  The documentation could then
provide example implementations for the putchar() functions for either
a hardware UART or a software UA[R]T as well, so programmers
interested in the functionality can cut&paste this out of the docs.

-- 
J"org Wunsch                                           Unix support engineer
address@hidden        http://www.interface-systems.de/~j/