how to use arm based protobuf

[darbee]

When we cross compile a project that depend protobuf such ROS.

1. first we cross compile protobuf for arm. then we get arm version libprotobuf* and a arm version tool named protoc( which can convert proto to .h .cc )
2. second we cross compile ROS on x86. ROS contain some file like a.proto and b.proto ..
   So, which version protoc should we use to convert those *.proto to *.h and .cc?
   I think we should use x86 version protoc instead of arm version protoc.
   But when we include headers and link dynamic libraries , we should use arm version, such as libprotobuf(arm)

These steps puzzled me，How should we use protobuf