Re: Accessing HWCAP on PowerPC?

[Ian Romanick <idr at us dot ibm dot com>]

Steve Munroe wrote:

> idr@us.ltcfwd.linux.ibm.com wrote on 10/12/2004 05:25:52 PM:
>
> > I was directed here by benh.  I really hope someone here has an answer
> > as I've spent a couple hours searching around the web and the glibc
> > 2.3.3 source.  Simply, how do I access AT_HWCAP from a library (i.e.,
> > can't get the auxvec passed to main)?
> >
> > I tried just accessing _dl_hwcap, but the link fails.  Do I just need
> > some "decorations" on the extern?  Am I barking up the right tree?
>
> _dl_hwcap is marked private so is not accessible outside of glibc.

I suspected it was something like that.  When I found that variable, I 
was pretty sure the leading _ was sign that it wasn't going to be exported.

> The Aux Vector is passed to main as the 4th parm.

What I'm trying to do is dynamically detect things like VMX to selected 
optimized routines at run-time in libGL and layered DRI drivers. 
Parameters passed to main do me no good. :(  I'm currently examining 
/proc/<pid>/auxv to get the information, but that's specific to 2.6.x 
Linux kernels.  I'd prefer a solution that will run on 2.4 kernels or BSD.