How to have OpenMP available on Yocto for iMX6?

[maurice]

Hello,

I have the the official release from Freescale to use Yocto. I created a sdk cross-toolchain by the command 'bitbake linux-imx -c populate-sdk' then I launched the script in tmp/deploy/sdk. Version of poky used is 1.5.3.

However, I want to use OpenMP in this cross-toolchain.

By default, the option of openMP is disable hence I modified  these recipes to comment the "--disable libgomp" :

• sources/poky/meta/recipes-core/gettext/gettext_0.18.3.1.bb
• sources/poky/meta/recipes-devtools/gcc/gcc-4.8.inc
• sources/poky/meta/recipes-devtools/gcc/gcc-cross-canadian.inc

Then, after creating  the sdk cross-toolchain, I have his error

"...i686-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/../../libexec/arm-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.8.1/ld: error:  hello uses VFP register arguments, ./libgomp.a(parallel.o) does not

... i686-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/../../libexec/arm-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/4.8.1/ld: failed to merge target specific data of file ./libgomp.a(parallel.o)"

Indeed, I need to use the option "-mfloat-abi=hard".

How can I do that?

Thank you

Maurice

[maurice · Accepted solution]

Hello,

One solution to have OpenMP is to edit the configure file "local.conf" by adding :

CORE_IMAGE_EXTRA_INSTALL += ”libgomp libgomp-dev libgomp-staticdev”

BR

Maurice

[igorpadykov]

Hi maurice

My opinion that this may be caused by specifics of hard float point

implementation on i.MX6. According to links below

"support for this lib [OpenMP] is only for ARMv7 arch ..only HardFloat can be used"

Also from sect.12.3.2 "Core configuration" IMX6DQRM  :

"FPU" is not present, only NEON. This may incur some

implications mentioned in links below

http://openmp.org/forum/viewtopic.php?f=3&t=1255

https://wiki.debian.org/ArmHardFloatPort

For speeding resolution I would suggest to post this

to meta-fsl-arm mailing list, so that our yocto developers

or someone familiar with Yocto/OpenMP integration could try

to assist you.

https://lists.yoctoproject.org/listinfo/meta-freescale

Best regards

chip

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