Re: iWMMXt Linux EABI cross toolchain

[Steven Newbury <s_j_newbury at yahoo dot co dot uk>]

--- Khem Raj <khem@mvista.com> wrote:

> Steven Newbury said the following on 03/03/2006 02:33 AM:
> > --- Mike Frysinger <vapier@gentoo.org> wrote:
> >
> >   
> >> On Thursday 02 March 2006 23:59, Steven Newbury wrote:
> >>     
> >>> --- Mike Frysinger <vapier@gentoo.org> wrote:
> >>>       
> >>>> On Thursday 02 March 2006 23:15, Steven Newbury wrote:
> >>>>         
> >>>>> OK I think I might have solved this.  The toolchain.eclass script was
> >>>>> enabling all languages when the glibc headers are present rather than
> >>>>> when glibc has been built.  When the configure script detects that c++
> >>>>> is a selected language it adds -shared-libgcc to the xgcc CFLAGS!
> >>>>>           
> >>>> err, what ?  toolchain.eclass ?  you're using Gentoo ?
> >>>>         
> >>> Yes! I'm using gentoo! :-) I have now got cross-gcc compiled with threads
> >>> so I should be able to build glibc (nptlonly) now fingers crossed.. I
> >>> couldn't get it to build without threads.  Hopefully I'll have more luck
> >>> now..
> >>>       
> >> well you should have said so in the first place, i would have probably
> paid a
> >>
> >> bit more attention as to what's going on
> >>
> >> how are you installing your cross-compiler ?  did you use crossdev or are
> you
> >>
> >> emerging stuff by yourself ?  arm/nptl doesnt exist in any of the current 
> >> Gentoo glibc ebuilds and i dont really plan on backporting anything ...
> >>     
> > That's no problem, I've created an overlay and using CVS HEAD
> > binutils/gcc/glibc.  AFAIK it's the only place with everything in.  I'm
> > emerging it all myself.
> >
> >
> > Seems glibc doesn't want to enable nptl for plain arm-* which it has
> wrongly
> > determined I'm using... I am using --with-cpu=iwmmxt --with-arch=iwmmxt
> > --with-abi=iwmmxt, it is of armv5e compatible.
> >   
> you should remove --with-abi=iwmmxt if you want a full EABI toolchain. 
> this option enables IWMMXT EABI which is somewhere inbetween EABI and 
> good old ARM ATPCS in addition you should select target as one of 
> arm-*-*-*eabi target in order to let configury know that you want an 

I am using arm-iwmmxt-linux-gnueabi, iwmmxt I am using in my gentoo ebuild
scripts to select the iwmmxt "--with-*" options etc.

There seems to be some disagreement on what the iWMMXt ABI is, I discussed this
on gnu@gcc.gnu.org:

--- Paul Brook <paul@codesourcery.com> wrote:

> On Wednesday 01 March 2006 05:05, Daniel Jacobowitz wrote:
> > On Wed, Mar 01, 2006 at 04:57:03AM +0000, Steven Newbury wrote:
> > > Thanks for the quick response!
> > > I'm sure it seems I like to make hard wok for myself! It gets worse, I'm
> > > porting Gentoo Linux to iWMMXt with pure EABI kernel and userspace.  I'm
> > > not concerned about being able to run old binaries. So is using
> > > abi=iwmmxt really not what I want? A really bad idea?
> >
> > Absolutely.  You want the AAPCS, not Intel's pre-AAPCS ABI.
> 
> Actually, -mabi=iwmmxt is AAPCS based. It's diffferent from the old intel 
> iwmmxt ABI.
> 
> Having said that, it probably hasn't been tested particularly well, and I 
> wouldn't advise using it unless you really need it (ie. you know you have 
> performace sensitive code that makes extensive use of iWMMXt vector types in 
> function arguments).

So is it just that the iWMMXt ABI is incomplete for EABI or untested or
something else?



Steve


		
___________________________________________________________ 
To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre. http://uk.security.yahoo.com

--
For unsubscribe information see http://sourceware.org/lists.html#faq