Re: [avr-libc-dev] FAQ addition / Proof-read

[Joerg Wunsch]

As daniel_laptop wrote:

> In the .noinit description at
>  
> http://savannah.nongnu.org/download/avr-libc/doc/avr-libc-user-manual/mem_sections.html#mem_sections
> 
> quote
> "
> It is possible to tell the linker explicitly where to place the .noinit
> section by adding
> -Wl,--section-start=.noinit=0x802000 to the avr-gcc command line at the
> linking stage.
> "
> 
> It would be good idea to add a NOTE that doing this will also move
> __heap_start (heap)
> to '.noinit start + size of noinit.'

Daniel, thanks for the reminder.

Could you please write up a paragraph explaining this, and provide a
patch for this?

> Att. is the .h file I use that enables external RAM and at runtime
> checks if _STDLIB_H_ defined (malloc) and if noinit section has been
> moved and sets __heap_start to __bss_end .  NOT THE BEST IDEA to
> check _STDLIB_H_ (library functions use malloc as well)

Well, i wouldn't like that approach too much.  It wastes some
instructions for things that could rather be done at link time
already.  Usually, the application programmer is expected to know
whether he's going to use malloc() or not. ;-)

Btw., it wouldn't catch cases like the use of <stdio.h> where stdio
function in turn will use malloc() but the application itself
doesn't...

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