仿照ucos的一个实时内核，专门为没有扩展ram的单片机写的，最低配置256字节。提供了四个优先级不同的任务和信号量互斥型信号量消息邮箱消息队列功能。-Ucos modeled a real-time kernel, designed for the microcontroller does not extend ram write a minimum configuration of 256 bytes. Provides four priority levels for different tasks and semaphores semaphore mutex type functions message mailbox message queue.