UCOS-II is a source code disclosed real-time operating system kernel.
Located its code, and the translation of Shao Beibei written by Jean J. Labrosse
Book, Jean J. Labross is developers of UCOS-II.
UCOS-II is a real-time operating system, more simple than Linux.
Related resources: http://www.ucos-ii.com
My UC / OS-II related articles
Global variable declaration in UC / OS-II
Compile UCOS under the PC