This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] ARM: Use different linker path for hardfloat ABI


On Wed, Apr 4, 2012 at 12:48 AM, Michael Hope <michael.hope@linaro.org> wrote:
> On 4 April 2012 11:11, Jakub Jelinek <jakub@redhat.com> wrote:
>> On Wed, Apr 04, 2012 at 09:18:59AM +1200, Michael Hope wrote:
>>> >> The subdirectories could be called fred and jim and it would still work.
>>> >> ?The only thing required is that this part of the naming scheme be
>>> >> agreed amongst the distros.
>>> >>
>>> >> This looks to me like it's turning into a bike-shed painting excerise
>>> >> between the distros out there. ?That's really sad.
>>> >
>>> > I don't think we ever even had the discussion: Debian invented their
>>> > Debian-internal scheme for managing multiple ABIs. ?They have in the past
>>> > used patched versions of gcc, as in the case of x86_64.
>>>
>>> (cc'ed cross-distro as the discussion is also going on there[1]. ?This
>>> patch continues that)
>>>
>>> I like the idea of incompatible binaries having different loaders.
>>> The path doesn't matter but the concept does. ?Like i686/x86_64, it
>>> gives distros the option to install different binaries alongside each
>>> other for compatibility, performance, or upgrade reasons. ?The
>>> compatibility cost is nice and low and lets Debian do some interesting
>>> cross development things.
>>
>> Does the dynamic linker itself contain any routines that depend on the
>> soft/hard ABI? ?That would quite surprise me, so I don't see the point of
>> having different dynamic linkers for those ABIs. ?One dynamic linker should
>> handle both just fine.
>>
>>> No one has released a hard float based distro yet. ?We have time to
>>> discuss and fix this so we don't get in the crazy situation where a
>>> third party binary only runs on some distros.
>>
>> Isn't e.g. Fedora 17/armv7hl a hard float based distro?
>
> Yip, as is Ubuntu Precise, Debian unstable, and a skew of Gentoo.
> None have been released yet. ?Here's my understanding:
>
> Fedora 17:
> ?* ARM is a secondary architecture
> ?* Alpha 1 release is out
> ?* Has both a ARMv5 soft float and ARMv7 hard float build

Beta isn't far off and we're working toward Primary Arch.

> Ubuntu Precise:
> ?* ARM is a primary architecture
> ?* Beta 2 is out
> ?* ARMv7 hard float by default with ARMv7 softfp being community supported
>
> Debian:
> ?* ARM is a primary architecture
> ?* Has a ARMv4T soft float and in-development ARMv7 hard float
>
> openSUSE:
> ?* Kicked off at a hackfest in September 2011
> ?* Have a ARMv5T soft float and ARMv7 hard float build

Is only hard float, they haven't ruled out doing v5 soft float but
it's not their current focus.

Peter


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]