[Ffmpeg-devel] bfin cpu specific build options

[Måns Rullgård]

Guillaume POIRIER said:
> Hi,
>
> On 2/21/07, M?ns Rullg?rd <mans at mansr.com> wrote:
>>
>> Marc Hoffman said:
>> > Not sure if this needs an explanation.
>> >
>> > Index: configure
>> > ===================================================================
>> > --- configure        (revision 8047)
>> > +++ configure        (working copy)
>> > @@ -1329,6 +1329,11 @@
>> >          sparc64)
>> >              add_cflags "-mcpu=v9"
>> >          ;;
>> > +        bf*) #bf531 bf532 bf533 bf561 bf5xx all get this config
>> > +            add_cflags "-mfdpic"
>> > +            add_ldflags "-mfdpic"
>> > +            add_ldflags "-Wl,--defsym,__stacksize=0x40000"
>> > +            ;;
>>
>> The ;; indentation is inconsistent.  Otherwise OK.  I don't know blackfin,
>> so I assume the options are correct.
>
> I'm curious about the necessity of specifying stack size value. Is
> this meant to optimize better, or is it necessary to just get ffmpeg
> to compile and run correctly?

That flag defines the symbol __stacksize as having the address, not value,
0x40000.  Presumably, there is a declaration such as extern long __stacksize;
in some header, but no actual definition in any source file.  One can only
hope that the loader actually store the stack size at this location.

-- 
M?ns Rullg?rd
mans at mansr.com