Hi Vladi,
in fact there is not a main.c, you have to find the "main" function, that lies elewhere in the code (that is Ft_Esd_Framework/Ft_Esd_app.c)
But be aware, the "while" loop in ESD architecture is part of Ft_Esd_MainLoop() in Ft_Esd_Framework/Ft_Esd_MainLoop.c
So,to integrate, I suggest creating a "init" stage just before the Ft_Esd_MainLoop() call in Ft_Esd_app.c file, and then use the already written while loop in the other file to insert your routine.
I had some struggle in that kind of integration at first sight, but if you work with EVE and some versioning tool (a git GUI , for example), you can:
-save yout eclipse project with git;
-export your interface into the eclipse project when needed;
-revert to the previous ( or simply not commit the new ones ) Ft_Esd_MainLoop.c and Ft_Esd_app.c
-continue editing building and so on.
My two cents.