Re: Phone call (was Re: Armhf dynamic linker path)

[Paulo César Pereira de Andrade <paulo dot cesar dot pereira dot de dot andrade at gmail dot com>]

Em 11 de abril de 2012 21:16, Michael Hope <michael.hope@linaro.org> escreveu:
> 2012/4/12 Paulo César Pereira de Andrade
> <paulo.cesar.pereira.de.andrade@gmail.com>:
>> Em 11 de abril de 2012 20:22, Michael Hope <michael.hope@linaro.org> escreveu:
>>> On 12 April 2012 10:38, Steve McIntyre <steve.mcintyre@linaro.org> wrote:
>>>> On Wed, Apr 11, 2012 at 02:06:09AM +0100, Steve McIntyre wrote:
>>>>>
>>>>>And here's the details as promised.
>>>>>
>>>>>I've started a wiki page at
>>>>>
>>>>>https://wiki.linaro.org/OfficeofCTO/HardFloat/LinkerPathCallApr2012
>>>>>
>>>>>with a strawman agenda for now, and a Doodle poll at
>>>>>
>>>>>http://www.doodle.com/93bitkqeb7auyxn7
>>>>>
>>>>>to see when the best time is for the call on Thursday/Friday. Please
>>>>>fill in the times that work for you ASAP and I'll announce the result
>>>>>during Wednesday. Ideally we'd like stakeholders from all the relevant
>>>>>distros and the upstream toolchain developers to be there, able to
>>>>>represent their groups and (importantly) able to make a decision here
>>>>>on what we should do.
>>>>>
>>>>>Apologies for the short notice, but we need a decision quickly.
>>>>
>>>> And the best time turns out to be Friday at 15:00 UTC (16:00 BST,
>>>> 11:00 EDT etc.). Of the 10 people who responded in the poll, the only
>>>> person who can't make that time is Michael in .nz. Sorry, Michael.
>>>
>>> All good. ?My vote is for /lib/ld-arm-linux-gnueabihf.so.3 as it:
>>> ?* is similar to /lib/ld-x86-64.so.2
>>> ?* keeps the libraries and loader in the same directory
>>> ?* doesn't invent a new /libhf directory
>>> ?* is easier to implement in GLIBC
>>> ?* is architecture and ABI unique
>>> ?* requires less change for distros where the hard float libraries are
>>> already in /lib
>>
>> ?Sorry for more bikeshedding, but afaik rpm based distros are
>> using the armv7hl identifier, so it could as well be
>>
>> /lib/ld-linux-armv7hl.so.3
>
> This includes the ABI (h), adds the endianess (l), and implies a
> architecture level (v7). ?The name for the most common configurations
> should be as short as possible so I'd rather drop the 'l' and add a
> 'b' or 'eb' if anyone wants a big endian distro in the future. ?The
> architecture level is a problem as the loader should also be valid on
> ARMv5 and ARMv6 hard float builds. ?Skype should be able to make a
> hard float binary that runs on everything, including a potential ARMv6
> hard float RaspberryPi build.

  This means ld.so (and what else? a skype binary should not come fully
statically linked) should be built with -march=armv5te? That is, common
denominator should be vfpv3-d16, ldrd/strd and thumb2 instruction set?
  AFAIK, for "user level", armv6 with vfp is effectively amv7 (sans armv7-r
that has a div instruction in thumb mode).

>> ?Other variant could be
>>
>> /armv7hl-linux/lib/ld.so.3
>
> This introduces both a new directory and a new style for naming :)

  Well, I said I was sorry for more bikeshedding :-)

> -- Michael

Paulo