How to cross-compile to install OpenCV on iMX6UL ?

[toanjunifer]

Hi NXPs,

My name is Toan. I installed opencv on python 2 successfully. I installed pt5-creator first and then I install opencv via source code. I successfully but it's take a long time. So how can I do cross-compile or anything else to reduce native-compile ? Use layer or recipe ?

Thank you again !

Best regards,

Toan

[weidong_sun]

Hello Toan,

 NXP provides a way to compile it in yocto. Actually, it only takes a long time to compile for the first time, because it needs to download relevant software packages. After that, the compilation speed will be very fast.

Have a nice day!

BR,

Weidong

[toanjunifer]

Hi weidong.sun‌,

Thank you for your response. I think this way is better than I do, which take very long time to native-compile.

May you show me that way ? It's very meaningful.

Thank you so much,

Toan

[weidong_sun · Accepted solution]

Hi Toan,

    it is very easy if you have download Yocto BSP via repo sync, and compiled it successfully.

if not, you should setup environment for Yocto.

---downloading linux document from the link

Embedded Linux for i.MX Applications Processors | NXP 

Supporting informtion

Select one version of linux bsp, and download it's document. 

then download yocto BSP and compile it according to steps in "i.MX_Yocto_Project_User's_Guide.pdf",  opencv on python 2 have been included.

Have a nice day!

BR,

Weidong

[toanjunifer]

Hi weidong.sun‌

As my main question above, I'm finding other way to execute cross-compile instead of native-compile on iMX6ULEVK. Because It's take a long time. So I think writing a recipe by myself may solved this problem. But I don't exactly what I need to do and does it's possible ?

Best regards,

Toan

[weidong_sun]

Hello Toan,

    I just tested meta-python2 in yocto , below is steps:

# cd ~/imx-yocto-bsp-L4.14.98-2.2.0/sources/meta-openembedded

# git clone https://git.openembedded.org/meta-python2

# cd meta-python2

# git checkout -b sumo origin/sumo

# cd ~/imx-yocto-bsp-L4.14.98-2.2.0/

# DISTRO=fsl-imx-fb MACHINE=imx6ulevk source fsl-setup-release.sh -b build-fb

(1) changing ./conf/bblayer.conf

...

#BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-python "
BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-python2 "

...

(2)changing networking's layer.conf

~/imx-yocto-bsp-L4.14.98-2.2.0/sources/meta-openembedded/meta-networking/conf/layer.conf

..
#LAYERDEPENDS_networking-layer += "meta-python"
LAYERDEPENDS_networking-layer += "meta-python2"
..

# bitbake python -c fetch

# bibake python -c compile

Have a nice day!

BR,

Weidong

[toanjunifer]

Hi weidong.sun‌,

Thank you for your response, but I think we have a mistake here. Maybe It's my wrong presentation.

Python is also can be added by modify "local.conf" file. It's easier than your way. Just adding "python" is enough. I mean I wanna install OpenCV on Python 2 by cross-compile. Using recipe, layer may be possible ?

Best regards,

Toan

[weidong_sun]

Hello Toan,

     I may have misunderstood the question you submitted before. Your goal is to call opencv Library in Python, so you want to achieve this goal when compiling in yocto.

    I looked up some materials, and did some tests in yocto. You can try it like this, which may help you.

Add these 2 lines to local.conf, please! 

......

IMAGE_INSTALL_append = " opencv python python-pip zbar"
PACKAGECONFIG_append_pn-opencv = " python"

......

good luck!

Have a nice day!

BR,

Weidong

[toanjunifer]

Hi weidong.sun‌,

I found that NXP has release a new kernel 4.19.35 which cantains python3-pyqt5 package. So this problem may not need to solve anymore.

Thank you for your support. 

Best regards, 

Toan

[weidong_sun]

You are welcome!

[toanjunifer]

Hi weidong.sun‌,

I tried follow your guide. But It's seem like not working. While building have no error but then I can not import cv2 from python 2 environment. I search some material It's say that opencv 4.0.1 is working good on python 2.7.

Note: While build I found a warning:

WARNING: opencv-4.0.1.imx+gitAUTOINC+737f8fad13_2522124473_32e315a5b1_34e4206aef_fccf7cd6a4_d29d003e00-r0 do_configure: QA Issue: opencv: invalid PACKAGECONFIG: python [invalid-packageconfig]

Best regards,

Toan

[toanjunifer]

Hi weidong.sun‌,

Thank you for your response. It's very worth to try. I will response whenever I done this.

Best regards,

Toan

[weidong_sun]

Hi Toan,

   You mean Yocto BSP includes Python3, but you want to use Python2,  and you hope Python2 can be added to Yocto, right?

Have a nice day!

Weidong

[toanjunifer]

Hi weidong.sun‌,

Currently, I'm using BSP kernel v4.14.98_2.0.0 and I build a distro successfully. I install successfully OpenCV on Python 3 by adding "opencv" and other relevant packages on "local.conf" file. But I can not install OpenCV on Python 2 by this way. Did you mean "very easy way" is modify local.conf file ?

Best regards,

Toan