[vdr] [ANNOUNCE] VDR developer version 1.3.49

Matthias Schwarzott zzam at gentoo.org
Sun Apr 30 11:18:03 CEST 2006


On Sunday 30 April 2006 11:06, Jörg Wendel wrote:
> On Sonntag 30 April 2006 10:50, Klaus Schmidinger wrote:
> > Darren Salt wrote:
> > > I demand that Klaus Schmidinger may or may not have written...
> > >
> > > [snip]
> > >
> > >> Apparently PIC is only available on special processors, especially
> > >> *not* Intel, [...]
> > >
> > > False. You need -fPIC for libraries on ARM, which means that you need
> > > it on XScale - and that's an Intel processor...
> >
> > I looked up the -fPIC option in "Using and Porting GNU CC",
> > version 2.95, where it says on page 110:
> >
> >    "This option makes a difference on the m68k, m88k, and the Sparc."
> >
> > Well, that manual is a little old, so maybe that information is
> > outdated...
> >
> > Klaus
>
> the same hint is still included in the manpage of "gcc (GCC) 4.0.2"
>
>        -fPIC
>            If supported for the target machine, emit position-independent
>            code, suitable for dynamic linking and avoiding any limit on the
>           size of the global offset table.  This option makes a difference
> on the m68k, PowerPC and SPARC.
>           Position-independent code requires special support, and therefore
>           works only on certain machines.
>
> i my idea is likewise that it doesn't care on Intel systems.
>

PIC does(!) make a change on Intel systems, too.

PIC = Position Independant Code
That means the compiler will not assamble absolute jumps but create a table 
with addresses to use indirect address lookup.

For a better description have a look at: 
http://www.gentoo.org/proj/en/hardened/pic-guide.xml
and
http://www.gentoo.org/proj/en/hardened/pic-internals.xml

Greetings
Matthias

-- 
Matthias Schwarzott
Gentoo Developer
http://www.gentoo.org



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