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bsarbb
Contributor
Contributor
266 Views
Registered: ‎03-11-2021

Petalinux gstreamer Support

Hello,

I am trying to enable gstreamer over petalinux development environment.
For this purpose, I simply enable packagegroup-petalinux-gstreamer configuration option with using petalinux-config command.
Then I searched gstreamer related recipes in ${PRJ_DIR}/components/yocto/layers directory. I found two gstreamer recipe.

  1. gstreamer1.0_%.bbappend
    This file is in meta-petalinux layer.
  2. gstreamer1.0_1.16.1.bb
    This file is in core layer.

Both of these layers are added to the "BBLAYERS" and both layer's priority (spesified with BBFILE_PRIORITY_xx) are same (5).

I made following changes to understand the recipe lookup process of bitbake.

  1. I corrupted valid github URL in  gstreamer1.0_%.bbappend.
    Linux system build process finished with error in this trial.
  2. I corrected the github URL then corrupted valid source code address in  gstreamer1.0_1.16.1.bb.
    This time build process finished successfully.
    From this, I understood that bitbake somehow decided to use use gstreamer1.0_%.bbappend recipe.

So How bitbake decide to use usegstreamer1.0_%.bbappend recipe ? What is the selection criteria ?

Also,

  1. I increased the priority of core layer from 5 to 6 and corrupt and again corrupted the source code address spesified in gstreamer1.0_1.16.1.bb.
    This time, I supposed to encounter with an error, but build process finished successfully again.

So,
Why this priority increment operation does not take effect ?

Thanks, 
 

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1 Reply
hokim
Scholar
Scholar
182 Views
Registered: ‎10-21-2015

Hi

The priorities between bb and bbappend  are irrelevant

bbappend always appends or overlays to bb

The priority among bbs and that among bbappends are separate

meta-layers.png

bbappends are appended in order of BBFILE_PRIORITY defined in each layer’s layer.conf file e.g. a bbappend in layer with BBFILE_PRIORITY = 5
will be appended before bbappend from another layer with BBFILE_PRIORIY = 6