Design And Implementation Of An Embedded Real-time OS Core AcoolOS

In the embedded field, with the enhancement of microprocessor performance, systemes are becoming more and more complex and the RTOS (Real Time Operating System) is used more and more widely. But on the market, most RTOS used are not free, even some free RTOS can be get in the net, but there are too many defects. For example, they provide too simple system services, too little application interface functions, and the reliability can't get guarantee. So the subject is to develop a realtime operating system core, namely AcoolOS(a cool operating system).The RTOS core AcoolOS, it is a real-time, preemptive, multitasking kernel designed for time-critical embedded applications. For the tasks which have the same priority, it schedules across time slice or the order that they become ready; for the interrupt, it provides two service routines:LISR (Low-Level Interrupt Service Routine) and HISR (High-Level Interrupt Service Routine), LISR is used for quick response to interrupt and HISR is for affairs which can be deal with later; for the communication of tasks, it provides information queue mechanism, for the synchronization of tasks, it provides a mutex semaphore, for the resource sharing, it provides counting semaphores, besides these, it provides memory and time management mechanism. These application interfaces are enough for users.AcoolOS adopts a kind of modular construction, it is convenient for users to tailor. In function, AcoolOS provides interface functions which are in common use such as task management, interrupt management, semaphore, time management, memory management and information queue and so on. The Bit-Priority arithmetic which is used in the AcoolOS makes sure that the time for the task's schedule is a constant.AcoolOS runs on ARM microprocessor well, and it has been applied in the practical project, and the effect is very well, and it has high reliability and hard real time.