>   I have seen some options that are default in eCos while compiling for
> which I can't find documentation. these are:
> -fdata-sections
> -fno-rtti
> -fno-exceptions
> -fvtable-gc
> -finit-priority
> -Wl,--gc-sections
>
>   Can somebody tell me what are they for or where is the documentation
> about those?

http://www.gnu.org/manual/

check out the manual for gcc, it has information about various command line
options.

>
>   I have also read that ffunction-sections is used but I don't
> understand why. It seems to generate worse code, which is its advantage?

-ffunction-sections causes functions to be put in their own section. used in
conjunction with --gc-sections, you get selective linking, so that functions
that aren't called aren't linked in to your final image.

-Dan

>
> --
> Rafael Rodríguez Velilla        rrv@tid.es
> Telefónica I+D          http://www.tid.es
> Telf: +34 - 91 337 4270
>
>
>
>