[yocto] Crosscompiling python extensions with yocto generated toolchains!?

[Daniel.]

Well, I've create a little script to create the needed variables used
by Yocto's python.

Here it is:

. $1
export BUILD_SYS=$(echo $CONFIGURE_FLAGS | tr -s ' ' '\n' | grep host
| cut -f2 -d=)
export HOST_SYS=$(echo $CONFIGURE_FLAGS | tr -s ' ' '\n' | grep build
| cut -f2 -d=)
export STAGING_INCDIR=${OECORE_TARGET_SYSROOT}/usr/include
export STAGING_LIBDIR=${OECORE_TARGET_SYSROOT}/usr/lib
export PATH=${OECORE_NATIVE_SYSROOT}/usr/bin/python-native:${PATH}

I save it to a file and source it passing the environment-setup-*
scritp that lives at my ${TMPDIR} folder.

After that I can crosscompile python extension to my target as usual
with `python setup.py build'


Regards,


2016-06-20 17:43 GMT-03:00 Daniel. <danielhilst at gmail.com>:
> My first doubt was how to trully cross-compile python extensions. Since I
> can't find anything usefull on internet I ask my self: How OE does it? It
> seems that OE uses an patched distutils to get bits build. This "assumption"
> comes from what I see at distutils/sysconfig.py that lives at
> build/tmp/sysroot/.. folder. After more digging I found this patch:
> http://git.yoctoproject.org/cgit.cgi/poky/tree/meta/recipes-devtools/python/python-native/12-distutils-prefix-is-inside-staging-area.patch?h=daisy
>
> The variables are aplied by this patch to the python-native (since I'm still
> in Daisy, shame on me). At the top of the patch we see:
>
> The proper prefix is inside our staging area.
>
> So I'll try to contact these people to track the "proper fix". Since
> crosscompiling python extensions is lacking of
>
> documentation reading the source and talking to the gurus is the only option
> avaible right now :) .
>
>
> Regards,
>
>
>
> 2016-06-20 16:23 GMT-03:00 Khem Raj <raj.khem at gmail.com>:
>>
>> On Mon, Jun 20, 2016 at 12:08 PM, Daniel. <danielhilst at gmail.com> wrote:
>> > I've found this recipe "python-pycurl" with exports libcurl to python.
>> > What
>> > I did was build it and take a look at temp folder to stalk what line is
>> > used
>> > to compile that stuff. Here it is:
>> >
>> > distutils_do_compile() {
>> >
>> >
>> > STAGING_INCDIR=/home/geckos/yocto/yocto-daisy/build_x11/tmp/sysroots/pharosserver-imx6/usr/include
>> > \
>> >
>> >
>> > STAGING_LIBDIR=/home/geckos/yocto/yocto-daisy/build_x11/tmp/sysroots/pharosserver-imx6/usr/lib
>> > \
>> >          BUILD_SYS=x86_64-linux HOST_SYS=arm-poky-linux-gnueabi \
>> >
>> >
>> > /home/geckos/yocto/yocto-daisy/build_x11/tmp/sysroots/x86_64-linux/usr/bin/python-native/python
>> > setup.py build  || \
>> >          bbfatal "python setup.py build_ext execution failed."
>> >
>> > }
>> >
>> >
>> > So I go to my extension's source folder and paste
>> >
>> > STAGING_INCDIR=/home/geckos/yocto/yocto-daisy/build_x11/tmp/sysroots/pharosserver-imx6/usr/include
>> > \
>> >
>> > STAGING_LIBDIR=/home/geckos/yocto/yocto-daisy/build_x11/tmp/sysroots/pharosserver-imx6/usr/lib
>> > \
>> > BUILD_SYS=x86_64-linux HOST_SYS=arm-poky-linux-gnueabi \
>> >
>> > /home/geckos/yocto/yocto-daisy/build_x11/tmp/sysroots/x86_64-linux/usr/bin/python-native/python
>> > setup.py build
>> >
>> > and everything works fine, I got my extension compiled. So, in what
>> > magic
>> > are these enviroment variables envolved? STAGING_INCDIR
>> > and STAGING_LIBDIR are OE stuff, what are these BUILD_SYS and HOST_SYS
>> > related?! I'm still searching, anyway thanks Khen for
>> > pointing me meta-python sources. It helped me a lot.
>>
>>
>> OE has several classes where common operations are abstracted out and
>> you can see that in recipes
>> e.g. inherit setuptools etc. you should copy the recipe which is
>> closest to your package and modify it
>> to use your package source etc. and make other needed tweaks.
>>
>> >
>> > Regards,
>> >
>> >
>> > 2016-06-20 15:29 GMT-03:00 Daniel. <danielhilst at gmail.com>:
>> >>
>> >> Thank you Khem!!
>> >>
>> >> Regards,
>> >>
>> >> 2016-06-20 15:02 GMT-03:00 Khem Raj <raj.khem at gmail.com>:
>> >>>
>> >>> On Mon, Jun 20, 2016 at 10:44 AM, Daniel. <danielhilst at gmail.com>
>> >>> wrote:
>> >>> > Hi everybody..
>> >>> >
>> >>> > I've been playing with python extensions. Now I want to compile a
>> >>> > simple
>> >>> > hello world extension
>> >>> > to my Yocto's target, but I really can't find any good resource
>> >>> > about
>> >>> > doing
>> >>> > it. So what is the teory behind it?
>> >>> >
>> >>> > I know that I need python headers "Python.h and others" and that I
>> >>> > need
>> >>> > distutils installed. After that everything is done by distutils and
>> >>> > setup.py
>> >>> > script, but what is done is a mistery. I found distutilscross on
>> >>> > internet
>> >>> > but no documentation about it!?
>> >>> >
>> >>> > How are python extensions cross-compiled by Yocto? Can somebody
>> >>> > point
>> >>> > me an
>> >>> > example?!
>> >>>
>> >>> take a look at meta-python.
>> >>>
>> >>> http://cgit.openembedded.org/meta-openembedded/tree/meta-python
>> >>>
>> >>> You might find some examples close to what you are looking for.
>> >>>
>> >>> >
>> >>> > Regards,
>> >>> >
>> >>> > --
>> >>> > "Do or do not. There is no try"
>> >>> >   Yoda Master
>> >>> >
>> >>> > --
>> >>> > _______________________________________________
>> >>> > yocto mailing list
>> >>> > yocto at yoctoproject.org
>> >>> > https://lists.yoctoproject.org/listinfo/yocto
>> >>> >
>> >>
>> >>
>> >>
>> >>
>> >> --
>> >> "Do or do not. There is no try"
>> >>   Yoda Master
>> >
>> >
>> >
>> >
>> > --
>> > "Do or do not. There is no try"
>> >   Yoda Master
>
>
>
>
> --
> "Do or do not. There is no try"
>   Yoda Master



-- 
"Do or do not. There is no try"
  Yoda Master