Re: [PATCH] [AArch64] Define BE loader name.

[Andrew Pinski <pinskia at gmail dot com>]

On Mon, Jan 13, 2014 at 10:16 AM, Steve McIntyre
<steve.mcintyre@linaro.org> wrote:
> [ I hope this threads OK - replying to the thread using the list
>   archives... ]
>
> Carlos wrote:
>>
>>We need technical arguments from both sides to reach consensus.
>>
>>Marcus has to come up with real reasons for needing the new dynamic
>>linker name.
>
> Carlos already contributed to a ML discussion that happened after
> Linaro Connect in November last year, where we had broad consensus
> from the distros about separating the dynamic linker names for BE and
> LE systems:
>
>   http://lists.linaro.org/pipermail/cross-distro/2013-November/000570.html
>
> As a background to that, I'm the team lead for Big Endian work in the
> Linaro Networking Group (LNG). For a variety of reasons we're working
> on supporting both BE and LE code on a single system and we're
> investigating various options. Yes, it's a *horrible* idea but there
> are people who really want to use this. I can envisage places where we
> may want to have have both BE and LE binaries co-existing in the same
> system, and it would be nice if that's not locked out here.
>
> I'll be honest: I *don't* think that the general purpose Linux distros
> are likely to care about BE ARM or AArch64 systems in the same way as
> us, but who knows what might come up?
>
>>Andrew, you need to come up with concrete reasons for not wanting to
>>use a symlink or a copy.
>>
>>This is *exactly* the same kind of change we made for the 32-bit ARM
>>hard-float dynamic linker name change.
>
> Yup, Been there, done that. In future, would it not make sense in
> general to try and keep dynamic linkers separated by default?
>
>>The only wrinkle is that a symlink doesn't actually work:
>>https://sourceware.org/ml/libc-alpha/2012-10/msg00670.html
>>
>>If Markus is suggesting using a symlink he'll have to look into the
>>problem I posted, because the last time I checked the symlink setup
>>didn't work and required a hack to be used until all binaries had
>>been migrated.
>
> Yup. :-( I remember the hack I came up with, and I've pointed Marcus
> at it to help him understand what we did and why:
>
>   http://anonscm.debian.org/viewvc/pkg-glibc/glibc-package/trunk/debian/patches/arm/local-soname-hack.diff?view=markup
>
>>Thankfully in the case of the hard-float dynamic linker name change
>>we had consensus that the name change was needed to support a mixed
>>environment.


I withdraw my objection to the patch.  Though I do feel this
discussion should have been done on the GCC/glibc list in addition to
the linaro cross distro list as not every one knows about that list.

Thanks,
Andrew Pinski

>
> Right.
>
> Cheers,
> --
> Steve McIntyre                                steve.mcintyre@linaro.org
> <http://www.linaro.org/> Linaro.org | Open source software for ARM SoCs
>