Design And Implementation Of Embedded Real - Time Operating System Based On AUTOSAR Specification

With the rapid development of science and technology, the quantity of electronic control units in a car is rising very steeply, which brings about increasing complexity of automotive electronic software development. For the sake of reusability and portability, the automotive industry launched the AUTOSAR specification in2004to shorten the development cycle and reduce cost. The AUTOSAR specification is composed of software development methodology, application programming interface and software architecture.The AUTOSAR specification received wide attention since its launch. The major manufacturers have chosen to upgrade from the OSEK/VDX specification to AUTOSAR specification. Currently, foreign development is significantly more advanced than domestic. In view of the AUTOSAR specification is becoming international standard for automotive electronic software field, it is necessary for us to research on AUTOSAR specification.FDOSEK is an8-bit real-time operation system based on OSEK/VDX specification, which is designed by Embedded System Lab of FUDAN University. According to AUTOSAR specification, we implemented an8-bit embedded real-time operation system on the basis of FDOSEK. The research content is as follows.1) With study of OSEK OS specification and AUTOSAR OS specification, we modified some data structures and application program interfaces of FDOSEK’S original parts, which are not compatible with AUTOSAR.2) With research on the new content of AUTOSAR and characteristics of8-bit microcontroller, we designed the following modules:schedule table, software free running timer, OS-application, timing protection, stack monitor and protection error handling.3) We implemented FDSAR OS on Freescale Corporation’s8-bit microcontroller MC9S08DZ60, supporting scalability class SCI and SC2.4) We performed function test and performance test for FDAR OS, which verified the correctness of functionality and the real-time performance and storage space meets the requirement of embedded system.In the design and implementation process of FDSAR OS, the innovation ideas are as follows.1) We brought about time-driven scheduling policy by using schedule table and optimized the algorithm of explicit synchronization.2) We realized a software free running timer by using a hardware timer and the corresponding interrupt service routine, which enhances the time management functionality.3) We use timing protection to monitor the running process of tasks to prevent timing errors’ propagation, which enhances the system’s reliability. Furthermore, we optimized some data structures and added macro switch to protection function, which reduces the system’s storage overhead.