Memory Management Of An ARM-based Embedded Real-Time Operating System

With the continuous development of embedded technology and more and more usedin real-time domain, Embedded Real-Time Operating System for all aspects ofperformance are put forward higher requirements. Some of the traditional Real-TimeOperating System which can not adapt to the needs of embedded real-time applicationsand gradually withdrew from the stage of history, and currently several embeddedreal-time operating systems which gain more success in business also have their owncharacteristics and limitations.Because of the real-time ability and predictability characteristics of the memorymanagement of embedded real-time operating systems, usually has a quick anddetermined memory management model, the more common features are not using publicvirtual storage technology, static memory management mechanism, a relatively simplememory protection mode. While the complexity of embedded applications grows, strongerrequirements are proposed to continuously improve flexibility and performance of thememory allocation and recovery mechanisms, and the security, stability and reliability ofmemory protection mechanisms.ARTs-OS is a microkernel-based, independent developed Embedded Real-TimeOperating System. This version is implemented on an ARM9platform, of which memorymanagement is based on completely private memory protection mode, and be made up ofthree main sub-module as heap memory management, virtual memory block managementand address space management, has some features as dynamically allocated memory ofthe kernel heap and user processes memory space, and the MMU-based address translationand protection mechanisms and so on. In the specific implementation process, mainlydescribed the memory allocation algorithms we used and how to improve and optimize therun-time problems, analysis of the adverse effects of the MMU mechanism to real-timesystem, and the reasonable implementation of programs and improvements.Finally, specific implemented the memory management of Embedded Real-Time Operating System ARTs-OS on an ARM9platform specific implementation, and lay thefoundation for further studies of memory management of real-time embedded operatingsystem.