High Confidence Embedded Real Time Operating System Design And Implementation

At present, with the development of pervasive computing, more and more embedded equipment implants into the related product, the system dependability request is higher and higher. Improving reliability is one of the greatest challenges for operating systems, developing the high dependability real-time embedded operating system is imminent. Most of these system failures are caused by the operating system's expansion procedure especially device drivers. Therefore may enhance the overall system dependability through enhancing driver dependability.This article has thoroughly studied related high dependability systematic and the high dependability computing method, puts forward one kind of high-dependable subsystem-Gasos which implant into ERTOS II, thus realizes the high dependability of embedded real-time operating system, and the operating system will transplant to the POWERPC 405 platform.To sum up, there are several innovative researches as follows:1. Through the massive collection material of dependability, from the relationship of fail, failure and bug, we discovered most of system failures are caused by the operating system's device drivers. Therefore so long as strengthened the dependability of device drivers also to strengthen the operating system dependability.2. There are thousands of device drivers, therefore the driver itself confirmation is very difficult to guarantee, thus proposed restoring of enhancement driver reliability, and the Gasos subsystem is facing the equipment driver and the user (application procedure), the simulation driver implementation to the application procedure is transparent.3. As a result of the driver multiplicity, enhancing the dependability of the driver, is very difficultly through enhances its dependability to enhance system dependability, profits from the database system's host-from machine guaranteed the data security, proposed the simulation method comes between the backup essence and the driver interactive data. The simulation driver backup data but doesn't carry out the processing data, and uses the object-oriented thought, a simulation driver corresponds a kind of device driver, thus reduces designs the Gasos subsystem's code quantity and enhances the subsystem's Portability.4. Making use of the code involvement technology, may let the subsystem involve between the core and the driver, and examines isolates the related driver, thus acts according to the failure information which detects, stimulates the corresponding simulation deriver manager and the simulation driver participates in the restoration of the device driver.5. Solved the processor initialization questions of transplanting ERTOS II into the POWERPC 405 platform.Based on above several aspect researches, this article puts forward one kind of high-dependable subsystem, which is embedded between the core and driver, observing their communication and simulating the recovery mechanism to recover the driver just when it fails. And Gasos is small, moreover is very few to the essence revision, does not revise the driver, thus may transplant conveniently into other embedded or commodity operating system. This article research has certain value and the significance to the further research of high dependability embedded real-time operating system.