Directory Structure
>i## Directory Structure
### root directory
1. app -- application project directory,create your own app here.
2. config -- system cmake config files directory.
3. doc -- api mannul directory.
4. sdk -- system libs and include header files directory.
5. tools -- development tools and resource directory.
6. others -- build and cmd script files.
### app directory
* cd in the app folder
* cd in the project folder "common"
