面向NB-IoT的微内核RTOS的设计与实现

Design and Implementation of Microkernel RTOS for NB-IoT

实时操作系统(Real-Time Operating System,RTOS)被广泛应用于窄带物联网(Narrow Band Internet of Things,NB-IoT)设备之中。这类设备对体积、能耗与稳定性有着严格的限制。NB-IoT设备多采用宏内核的RTOS,能得到较好的运行性能,但要求更多的硬件资源,并且内核中出现的问题很可能会导致整个系统崩溃。该文对传统RTOS进行改进,设计开发了无内存管理单元(Memory Management Unit,MMU)的微内核实时操作系统(nM-MKRTOS)。该系统针对NB-IoT中资源较少的设备,利用微内核的优势,其通过动态加载与链接(Dynamic Loading and Dynamic Linking,DL 2)技术实现内存复用和快速启动,并采用模块化开发的方式提高系统稳定性。在实际测试中,nM-MKRTOS通过内存复用技术将内存利用率提高了56.25%;在系统的启动测试中,通过在DL 2技术中引入权重加载,系统的核心功能在三个任务子集上的启动时间分别减少57.59%、52.55%与47.59%。该系统能够广泛应用于智慧农业、智慧校园等场合,能够降低系统成本,提高系统稳定性。

Real-Time Operating System(RTOS)is widely used in Narrow Band Internet of Things(NB-IoT)devices.NB-IoT devices mostly use RTOS with macro kernel,which can get better performance but requires more hardware resources and problems in the kernel may cause the whole system to crash.In this paper,we improve the traditional RTOS and design and develop the nM-MKRTOS without Memory Management Unit(MMU).Aiming at the devices with fewer resources in NB-IoT,the system realizes memory reuse and fast startup through Dynamic Loading and Dynamic Linking(DL 2)according to the advantages of microkernel,and adopts modular development to improve system stability.In the actual test,nM-MKRTOS has improved memory utilization by 56.25%through memory reuse technology.In the system startup test,by introducing weighted loading in DL 2 technology,the startup time of the core functions of the system was reduced by 57.59%,52.55%and 47.59%for the three task subsets respectively.The system can be widely used in smart agriculture,smart campus,etc.,which can reduce system cost and improve system stability.