Sorry folks, the question was vague and the begining of a development...
Apparently to make Qt Quick Scene Graph work on an embedded system displaying GUI on the frame buffer, we need to recompile Qt on Yocto, and provide fake/dummy libraries ligEGL.so and libGLES.so
Obviously it will be rendered using software, as there is no hardware graphic support in that case, but it still needs "empty" libGLES.so to do so.
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