Research And Implementation Of Memory Spatial Isolation Technology For Embedded Systems

Nowadays, embedded systems were widely applied in the world. How to guarantee the systems'reliability becomes an important research field. From the perspective of spatial protection in embedded systems, an embedded software run-time environment which supports high reliability and hard real-time performance was designed, and drew on ARINC653 with its idea of temporal and spatial isolation. Research and improvement was made for isolation techniques of memory space in embedded systems from the following fields.First, the design ideas of typical embedded RTOS for temporal and spatial isolation were analyzed. The modern memory protection mechanism and realization methods were summarized. Some disadvantages were pointed out.Second, an RTOS kernel structure based on process isolated domain model and two level schedule models on the microprocessor with MMU supported was put forward. The spatial isolation model was made for preventing memory from accessing without permissions.At last, the paper implemented a RTOS prototype based on process isolated domain model and two level schedule model. This kernel was improved fromμC/OS-Ⅱ. New functions were included:process isolation based on space, effective dynamic memory allocation and the I/O space protection.