This post is about how to use Ubuntu to cross-compile C/C++ programs that run on LinkIt Smart 7688 Duo running OpenWRT Chaos Calmer 15.05.1 r49203 .
It's assumed that the SDK has been downloaded and installed on the Ubuntu machine. If it hasn't been installed, please refer to http://wei48221.blogspot.tw/2017/05/linkit-smart-7688-7688-duo-using.html for instructions on how to download and install it.
Note, the method described below builds an executable file that can be executed directly by using the "./filename" command.