Android Source Code Porting to Lenovo Tab2 A10-70F Device

[adrian98985]

Hi.
I would like to build own Android Image (especially to have own system
keys) for Lenovo tablet (A10-70F).
I followed tutorials like this:
https://source.android.com/source/requirements.html and this:
http://forum.xda-developers.com/chef-central/android/tutorial-compile-lollipop-ubuntu-t2929410
- based on first one.
I stuck on step "~How to add a device to list ~". On Android site it
is written about defining own Makefiles. I need more detailed
clarification in this case.
I found some sources on support page
http://support.lenovo.com/pl/en/products/tablets/a-series/a10-70-2?tabName=Downloads&linkTrack=Mast:SubNav:Support:Drivers%20and%20Software|Drivers%20and%20Software&beta=false
but I have no idea how to use it - if it is possible to use?. Lenovo
has shared some code but don't see any support to use it...

Thanks in advance for your help.