[pjsip] Error using pj_pool_create_on_buf

[fabio cherchi]

Hi Benny et al,

I'm developing my application on nios2-uclinux environment.
I would like to improve media performances by using on-chip-memory 
instead of external memory.

Based on the PJSIP documentation this implementation is possibile by 
using pj_pool_create_on_buf function instead of pj_pool_create.

I tried it as first attempt without setting any memory address:
 
  ...
  char buf[4096];
  ...
  pool = pj_pool_create_on_buf("app", buf, sizeof(buf));
  ...   
  status=pjmedia_conf_create(  pool,...
  ...

when I execute the application I get the following error:

 ...
 16:04:43.788       except.c  !!!FATAL: unhandled exception PJLIB/No memory!

Am I missing some additional function?

Thanks,
Fabio