The Implementation & Application Of A μITRON 4.0-spec Real-time Operating System

RTOS (Real Time Operating System) ,also called real-tme kernel, is one of the most important technology of embedded system. RTOS supports multiple tasks, it makes the development of application program simple and fast, and eases the maintenance and secondary development of the system, moreover, it also significantly strengthens the system's stability and reliability.μITRON is a series of mature specifications to design and implement RTOS, it has been more than 20 years since the first version ofμITRON specification comes to be existence. There are quanties ofμITRON-spec real-time kernels widely being used in many areas, in Japan, theμITRON is de-fecto standard of RTOS.The J-Kernel implemented in this paper is a compact and fast real-time kernel for the 32bits processors, it coforms toμITRON 4.0 specification. It has provided the most commonly used functionalities of RTOS such as task management, interrupt management, semaphore, mutex, mailbox, data-queue and event-flag. The J-Kernel is written in generic C programming language, therefore, it owns good portability, in theory, it could be port to any architecture's 32bits processors.The port of J-Kernel to ARM processor has been finished in this paper. Nowadays, ARM processors are the most popular embedded processors, they are widely used in many areas, by statistic, ARM processors have dominated the 75% market of 32bits RISC processors.Meanwhile, this paper has also made a benchmark and evaluation of J-Kernel by Thread-Metric. Thread-Metric is an open source test suite for measuring RTOS performance; it is introduced by Express Logic (the owner of ThreadX RTOS), and is freely available for developers to utilize.The last chapter of this paper is a user manual of J-Kernel, the methods of how to config and start kernel, create and manage tasks, create and utilize kernel resource, etc. of J-Kernel are introduced in detail in this manual in the form of sample code, this will greatly help the developers to learn how to use J-Kernel in a short time.