Qt and detecting iWMMXT

Qt and detecting iWMMXT

[Holger Freyther]

Hi all,

when building for XScale one could pass -iwmmxt to the configure script. Now
how can a recipe find out if XScale systems are targeted? The closest thing I
can think of is to look at PACKAGE_ARCH and see if xscale is in it.

Is there a better way?

Re: Qt and detecting iWMMXT

[Frans Meulenbroeks]

2010/9/24 Holger Freyther <holger+oe@freyther.de>:
> Hi all,
>
> when building for XScale one could pass -iwmmxt to the configure script. Now
> how can a recipe find out if XScale systems are targeted? The closest thing I
> can think of is to look at PACKAGE_ARCH and see if xscale is in it.
>
> Is there a better way?

Is this something which is xscale specific
or is it armv5te specific ?
In the latter case I guess something like
EXTRA_OECONF_armv5te could be used

Frans

Re: Qt and detecting iWMMXT

[Holger Freyther]

On 09/25/2010 05:06 AM, Frans Meulenbroeks wrote:

> 
> Is this something which is xscale specific
> or is it armv5te specific ?

It is a Co-Processor from Intel, it is only available in the Marvel SoC
(PXA270, PXA3x... maybe the 168 series as well).

Re: Qt and detecting iWMMXT

[Koen Kooi]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 24-09-10 22:59, Holger Freyther wrote:
> Hi all,
> 
> when building for XScale one could pass -iwmmxt to the configure script. Now
> how can a recipe find out if XScale systems are targeted? The closest thing I
> can think of is to look at PACKAGE_ARCH and see if xscale is in it.

Adapted from the mplayer magic Graeme and I came up with some years ago:

#build with support for the iwmmxt instruction (pxa270 and up)
MY_ARCH := "${PACKAGE_ARCH}"
PACKAGE_ARCH = "${@base_contains('MACHINE_FEATURES', 'iwmmxt', 'iwmmxt',
'${MY_ARCH}',d)}"

QT_CONFIG_FLAGS_append = " ${@base_contains('MACHINE_FEATURES',
'iwmmxt', ' -iwmmxt', '',d)} "

regards,

Koen
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (Darwin)

iD8DBQFMnSIlMkyGM64RGpERAumBAKCU8rfNBZ7GTmSgJwgKZ25iWom2xwCgt6hF
T3hkQK3OSWktYh6IYsUghmE=
=odW5
-----END PGP SIGNATURE-----

Re: Qt and detecting iWMMXT

[Frans Meulenbroeks]

2010/9/25 Koen Kooi <k.kooi@student.utwente.nl>:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 24-09-10 22:59, Holger Freyther wrote:
>> Hi all,
>>
>> when building for XScale one could pass -iwmmxt to the configure script. Now
>> how can a recipe find out if XScale systems are targeted? The closest thing I
>> can think of is to look at PACKAGE_ARCH and see if xscale is in it.
>
> Adapted from the mplayer magic Graeme and I came up with some years ago:
>
> #build with support for the iwmmxt instruction (pxa270 and up)
> MY_ARCH := "${PACKAGE_ARCH}"
> PACKAGE_ARCH = "${@base_contains('MACHINE_FEATURES', 'iwmmxt', 'iwmmxt',
> '${MY_ARCH}',d)}"
>
> QT_CONFIG_FLAGS_append = " ${@base_contains('MACHINE_FEATURES',
> 'iwmmxt', ' -iwmmxt', '',d)} "
>
> regards,
>
> Koen

Nice solution.
Guess it would be useful to have a list of all possible
MACHINE_FEATURES and DISTRO_FEATURES somewhere (e.g. wiki)

Frans

Re: Qt and detecting iWMMXT

[Frans Meulenbroeks]

2010/9/25 Frans Meulenbroeks <fransmeulenbroeks@gmail.com>:
> 2010/9/25 Koen Kooi <k.kooi@student.utwente.nl>:
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> On 24-09-10 22:59, Holger Freyther wrote:
>>> Hi all,
>>>
>>> when building for XScale one could pass -iwmmxt to the configure script. Now
>>> how can a recipe find out if XScale systems are targeted? The closest thing I
>>> can think of is to look at PACKAGE_ARCH and see if xscale is in it.
>>
>> Adapted from the mplayer magic Graeme and I came up with some years ago:
>>
>> #build with support for the iwmmxt instruction (pxa270 and up)
>> MY_ARCH := "${PACKAGE_ARCH}"
>> PACKAGE_ARCH = "${@base_contains('MACHINE_FEATURES', 'iwmmxt', 'iwmmxt',
>> '${MY_ARCH}',d)}"
>>
>> QT_CONFIG_FLAGS_append = " ${@base_contains('MACHINE_FEATURES',
>> 'iwmmxt', ' -iwmmxt', '',d)} "
>>
>> regards,
>>
>> Koen
>
> Nice solution.
> Guess it would be useful to have a list of all possible
> MACHINE_FEATURES and DISTRO_FEATURES somewhere (e.g. wiki)
>
> Frans
>
Rethinking the issue: assuming we *do* want SOC_FAMILY would it not be
more appropriate to use that here?

Frans

Re: Qt and detecting iWMMXT

[Eric Bénard]

Le 25/09/2010 10:18, Frans Meulenbroeks a écrit :
> 2010/9/25 Frans Meulenbroeks<fransmeulenbroeks@gmail.com>:
>> 2010/9/25 Koen Kooi<k.kooi@student.utwente.nl>:
>>> #build with support for the iwmmxt instruction (pxa270 and up)
>>> MY_ARCH := "${PACKAGE_ARCH}"
>>> PACKAGE_ARCH = "${@base_contains('MACHINE_FEATURES', 'iwmmxt', 'iwmmxt',
>>> '${MY_ARCH}',d)}"
>>>
>>> QT_CONFIG_FLAGS_append = " ${@base_contains('MACHINE_FEATURES',
>>> 'iwmmxt', ' -iwmmxt', '',d)} "
>>>
>>> regards,
>>>
>>> Koen
>>
>> Nice solution.
>> Guess it would be useful to have a list of all possible
>> MACHINE_FEATURES and DISTRO_FEATURES somewhere (e.g. wiki)
>>
>> Frans
>>
> Rethinking the issue: assuming we *do* want SOC_FAMILY would it not be
> more appropriate to use that here?
>
you can have a SOC which supports iwmmx and wish not using it so 
MACHINE_FEATURES seems sane here.

Eric

Re: Qt and detecting iWMMXT

[Enrico Scholz]

Holger Freyther <holger+oe@freyther.de> writes:

> when building for XScale one could pass -iwmmxt to the configure
> script. 

I would avoid -march=iwmmxt because

a) there seems to be kernel bug which does not restore IWMMXT state on
   ELF loading[1]

b) gcc 4.4.4 is bugged for this architecture (both ICE and generation of
   inefficent code) and fails e.g. to bootstrap itself or glibc


When you really need iwmmxt support, I recommend to add '.arch iwmmxt'
to (inline) assembler instead of using -march=iwmmxt.


Enrico

Footnotes: 
[1]  http://article.gmane.org/gmane.linux.ports.arm.general/11795