Re: [Xenomai] xenomai/ipipe arm64 port

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On Tue, Sep 29, 2015 at 10:31:29AM -0700, Dmitriy Cherkasov wrote:
> 
> 
> On 09/29/2015 05:54 AM, Jorge Ramirez Ortiz wrote:
> > On 09/28/2015 08:12 PM, Gilles Chanteperdrix wrote:
> >> On Mon, Sep 28, 2015 at 04:57:28PM -0700, Dmitriy Cherkasov wrote:
> >> Ok, this page:
> >> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0024a/CJHECGIH.html
> >>
> >> seems to indicate that armv8 may or may not trap upon
> >> exception. Or maybe the exceptions can be enabled with the FPCR
> >> register? Or the glibc functions defined in the fenv.h header?
> >>
> > the way it is worded it appears to be a decision left to the SoC vendor.
> > I'll post the question to support@arm.com for confirmation.
> >
>  From some earlier docs, it looks like it was possible to toggle 
> trapping with FPCR, but as Lennart mentioned those bits appear to now be 
> reserved. On our hardware, setting them has no effect.
> 
> 
> I also enjoyed this part:
> 
> Both floating-point and NEON are required in all standard ARMv8 
> implementations. However, implementations targeting specialized markets 
> may support the following combinations:
> 
>   *
> 
>     No NEON or floating-point

Well, I guess there is a difference between "standard" and
"implementation targeting specialized markets".

-- 
					    Gilles.
https://click-hack.org