一个自己独立开发的模拟任务切换的简易内核，采用动态私有任务栈，时间片轮询模式用户还可自行添加新的线程；经过测试，没有问题。适用于Arm7内核的各款芯片-Simple kernel of an independently developed simulation task switching, dynamic private task stack, the time slice polling mode, users can also add their own new thread teste