Reducing the size of an RTEMS application

[Oyake, Amalaye (398F)]

Thank you for the replies Chris, Joel and Gedare:

I read the following: https://docs.rtems.org/releases/rtemsdocs-4.6.2/share/rtems/html/FAQ/FAQ00069.html

And using sparc-rtems4.12-strip (I am using RTEMS ‘4.12’ pulled from git), I got a reduction from 7.3M to 754K, which is more in line with what I expected. However, I am interested in reducing things more.

Are the options -ffunction-sections and -fdata-sections turned on by default? Also what determines the size of the in-memory file system?

I will look at the gcc optimization options.

I will look at the configure options.

Regards,
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* Amalaye Oyake                                       *
* Instrument Product Software Development Group  */\  *
* Jet Propulsion Laboratory, Pasadena            *||  *
* CA 91109                                       /||\ *
**************************************************^^***
 

On 11/1/16, 10:51 AM, "Chris Johns" <chrisj at rtems.org> wrote:

    On 31/10/16 10:36 pm, Oyake, Amalaye (398F) wrote:
    > 
    > I am building a Leon-3 application for a resource constrained platform
    > (very little RAM). How can I reduce the size of the RTEMS application?
    > Beyond normal RTEMS kernel configuration, turning off debugging and
    > optimizing with –O, are there ways to strip out any unnecessary symbols
    > after compilation.
    
    Which version of RTEMS? The master for up coming 4.12 supports function
    sections and that may help.
    
    I think reducing the size will be an exercise in isolating each part and
    removing it. The static sizes can be reviewing using something like:
    
     $ sparc-rtems4.12-nm --size-sort --print-size --reverse-sort \
        sparc-rtems4.12/c/sis/testsuites/samples/ticker/ticker.exe | less
    
    and to look at just the RAM usage:
    
     $ sparc-rtems4.12-nm --size-sort --print-size --reverse-sort \
        sparc-rtems4.12/c/sis/testsuites/samples/ticker/ticker.exe | \
        grep " [BDdb] "
    
    The dynamic memory will be a little more difficult.
    
    The memory usage will depend on the services you use. It would be nice
    to know the effect the new RTEMS printer interface would make.
    
    Chris