Inango has released a cross-referencing layer for Yocto systems. The code is free and available from git.inango.com (you will be asked to register) and may be downloaded from the following location:
https://git.inango.com/yocto/meta-inango-crossreference.

The cross-reference layer is added to your Yocto build system and automatically generates ctags (or cscope) files for each package and the entire distro. The ctags file may then be used with editors such as vi, vim, emacs and others.

This layer is part of Inango’s on-going efforts to create valuable and time-saving tools for Yocto developers. Our current tools already include a Yocto validation tool (ZIKIT) and development editor (YDE) – with a roadmap that will include much more. Please contact us for further details.

You can watch our short demonstration movie on the cross-reference layer here.