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Re: Freeing __malloc_av and impure_data
On Nov 26 15:42, Aras Vaichas wrote:
> Hi, I'm building a binary for a non-Linux embedded AVR32 application
> and I'm getting close to my 16K of SRAM limit.
>
> Looking at my elf file, I see that impure_data uses 1K of memory.
>
> 00000044 l O .data 00000400 impure_data
>
> I understand that it is somehow used for rentrancy in newlib, but
> AFAIK I don't need it.
>
> Is there a way to reduce this, or remove it completely?
You can't just remove it since it's used for more than just reentrency.
But you can shrink it for small targets. The --enable-newlib-reent-small
configure option will do that for you.
> There is also a whole load of malloc related data as well:
>
> 00000444 g O .data 00000408 __malloc_av_
>
> Can I free that up as well?
>
> I use very little of newlib, and I've even replaced the stdio library
> with my own to reduce the overall size and footprint. It would be
> great if I could also remove or reduce these two symbols.
You can get rid of it by overriding newlib's malloc with your own
malloc. Just define MALLOC_PROVIDED so the default malloc functionality
will not be built into newlib. Alternatively, make sure not to use
functions which potentially allocate space dynamically. printf is a
good candidate.
Corinna
--
Corinna Vinschen
Cygwin Project Co-Leader
Red Hat