Re: [Dri-devel] DRM janitorial

[F. <jrf...@tu...>]

On Tue, Jun 03, 2003 at 09:31:27AM -0700, Linus Torvalds wrote:
> 
> On Tue, 3 Jun 2003, [iso-8859-15] José Fonseca wrote:
> > 
> > According with archives
> > (http://dri.sourceforge.net/doc/faq/architecture.html#DRM-SUB-DRIVERS),
> > Linus wanted the DRM drivers to be independent.
> 
> I wanted that because the old code was total crap, and the makefiles could 
> never get the compiled-in case to work.
> 
> I don't think it's a goodness in itself, but it was basically a 
> _requirement_ for DRI back then. The library routines were horribly hacky, 
> and depended on config options, so they were impossible to compile in and 
> then load one driver later.
> 
> My only real underlying requirement is that compiled-in stuff works. I 
> personally refuse to use modules, since I see no point to them when I 
> compile the kernel for my machine _anyway_. 
> 
> To me modules are either
>  - "distribution kernels" (either things like RedHat/SuSE, or just local 
>    MIS distrubutions)
>  - development (load a module, test, unload, fix, load again)
> 
> and make zero sense otherwise when you have full sources.

Thanks for the heads up and your POV in this matter.  This will have to
be more thoroughly discussed before any decision is made since it can
affect other things (such as IHV DRM based drivers).

But before we reach the merits discussion I'd like to know how the
symbol linking differs when a driver is loaded as a module or is
statically linked in the kernel.  I tried to search about this:
/usr/src/linux doesn't have much infor about it, google just gives
rubish for all keywords combinations I can think of, but
http://www.xml.com/ldd/chapter/book/ch02.html#t3 has some info.

IIUC, at least for modules, the symbols which we want to make available
to other modules usually have to be specificaly declared (with
EXPORT_SYMBOL). Therefore each module it's "own namespace", i.e., two
different modules with some public symbol with the same name on each
module doesn't lead to a duplicate symbol unless they both are exported.

But for statically linked kernels, can we or not have two equally named
non-static not-exported symbols living in two different source files?

José Fonseca