[maemo-developers] Soft and hard float

[From: Javier S. Pedro]

2012/9/10 Marcin Mielniczuk <marmistrz at linux.pl>:
> Hardfp seems to not be the problem. I checked two apps segfaulting on
> 0x00000000 and 2 apps running ok.
> readelf -A gives the same output (attatched) for all of them
>
> The apps were: segfaulting MeegoQQ and AccuWeather (wxapp),
> working allegro and QToDo.
>
> What may cause the segfaults? filebox for N9 causes this kind of fault too.
> I'm using cssu testing (not thumb flavor)

Note that the dynamic loader will happily link two binaries using hard
and softfp. Therefore, problems of this nature will seemingly appear
randomly, depending on where and when an app does floating point
calls. It does not matter if you link hard with softfp if neither is
doing any function call containing floating point parameters / return
types. As soon as one such call is made, then things MAY go wrong, and
in ways you'd never expect.

As usual when you approach the "undefined behavior" area, whatever you
experience might be caused by this, or might be caused by the phase of
the moon (aka something entirely different, unrelated, and often
totally unexpected :) ).

Javier.