Porting And Optimization Of Dalvik Virtual Machine Of Android On Loongson-based Platform

With the promotion of Android platform in mobile termination such as cellphone and the further expansion of market-oriented of Loongson processor,it will be of great signifiance that Android is deployed to Loongson platform for the extension of Loongson-based industrialization.Dalvik virtual machine is one of core components of Android runtime environment and researching the porting and optimization techniques of Dalvik virtual machine on Loongson platform has become an urgent task in order to improve the performance of Android applications on Loongson platform.Dalvik is a high-performance Java virtual machine that Google designed for Android platform,and the architecture of Dalvik is register-based.The registers in the virtual machine will be more closely mapped to the registers on the target machine,so the Dalvik runing on the RISC machine has great advantage.On the side,a set of new instruction and the executable file format are used by Dalvik virtual machine in order to improve the performance.The realization of the Dalvik virtual machine running on the equipment which has less system resource will have better performance than the Java virtual machine.This dissertation mainly foucus on the running mechanism and realization of porting and optimization of the Dalvik virtual machine on Loongson platform.First,the bytecode instruction set and executable file format were analyzed according to the specification of Dalvik virtual machine.Then Dalvik was studied,and the internal architecture and operation mechanism of virtual machine were analysed.Then the primary function modules of Dalvik virtual machine such as class loader,constant pool analyzer,interpreter and runtime environment were studied.Later,the realization of Dalvik interpreter based on Loongson platform was presented,and the interpreter of each bytecode was realized by using assemble program of Loongson.Finally,the Dalvik JNI method invocation module was optimized according to the characteristics of Loongson,and the implementation of Dalvik JIT compiler was studied in detail.Finally,with the help of oprofile performance analysis tool,Dalvik virtual machine that had been ported to Loongson platform and that had been optimized were analyzed,after comparing the data,the result of optimizing JNI method calls for Loongson platform made an satisfying effect.