After switching to ivi-shell, the screen is totally black.

I’m trying to porting ivi-shell. I added a recipes to my Yocto project, ivi-shell.so ,ivi-controller.so are build successfully. Then I try to modify /etc/xdg/weston/weston.ini as below

[core]
shell=ivi-shell.so
modules=ivi-controller.so
[ivi-shell]
ivi-input-module=ivi-input-controller.so

But when I run weston, nothing showed.
I tried to call layer-add-surfaces -l 1000 -s 2 & & layer-add-surfaces, didn’t see error logs
And I tried to call LayerManagerControl get surfaces, found that surface number is 0

Is there any one who can give me a hint/clue ?
Where should I start debugging?

Thanks a lot