Research Of Key Techniques In Trusted Embedded Three-Dimension Graphics System

In the post-PC era,the requirement of the embedded 3D graphics acceleration system is growing.Many restrictions,such as chip area,performance,power,costs and so on should be taken into account in the design of 3D graphics acceleration on embedded devices.Not only that,with the advent of the Internet age,It is also necessary to figure out the security issues of the data transmission for embedded devices in the network environment.So,there are some requirements for embedded applications as follows:stable and reliable high-performance embedded hardware platforms,suitable embedded operating systems,3D graphics accelerator suitable to embedded environment.To meet the requirement of these embedded 3D graphics acceleration system,a scheme of trusted embedded 3D graphics acceleration system with security function, based on a RISC microprocessor,are presented,and some key technologies,such as embedded technology,graphics acceleration,security technology,are analyzed.There are following designs:1)High reliable hardware platform based LEON3 and embedded Linux operating system are adopted,which ensure the stability of the whole embedded system,2)Self-designed 3D graphics acceleration module is added to the platform to improve the performance of embedded 3D graphics acceleration.3) A suit of encryption and authentication schemes are designed for the above platform running in the network environment,and ensure the security of data.All the three parts constitute a trusted embedded 3D graphics acceleration system,which has good practical value.The main contributions and innovations:1)An overall structure and security model of trusted embedded 3D graphics acceleration system is presented.Based on high-reliability LEON3 processor platform and embedded Linux operating system,and combined with encryption and authentication algorithms,the system with independent design of the 3D graphics acceleration module ensures the safety of graphics data transmission and real-time processing. 2)The technical features of the LEON3 RISC microprocessor,such as architecture,command systems,fault-tolerant and configurable,are deeply analyzed and researched.According to actual requirement,a detailed customization is made to achieve a high-reliability and high-performance trusted embedded system hardware platform.3)The architecture,core subsystems,file structure and boot process of embedded Linux operating system are analyzed in detail,and the replant work are completed on the designed LEON3 hardware platform.There are specific descriptions about the customization of system and the realization of NFS network file system.4)According to partition principle between hardware and software,the designs of 3D graphics acceleration on embedded system are presented.Embedded microprocessor is used to compute the geometric phase of graphics acceleration,and hardware IP core is used to realize the rasterization phase.The way of fixed point is adopted in the whole algorithm.In the geometric phase,optimizations are made to improve the three-dimensional cutting algorithm.We apply two-dimensional cutting and interpolation respectively on six sides of 3D perspective to reduce the calculation and computing burden of CPU.In the rasterization phase,methods based on tile are applied to reduce the calculation of scan conversion and texture mapping,keeping a good image quality.In texture mapping,texture compression and two Cache design are used to achieve a 6:1 compression ratio with S3TC compression algorithm.The cost of bus bandwidth is decreased too.Mipmap and bilinear filtering are used to improve the speed of texture mapping and achieve a good quality of rendering.5)Security problems of 3D graphics data transmission in the network environment are studied,and optimization as selective encryption is presented. Cryptosystem of AES and SHA-1 are combined with RSA key management to present a security model.Satisfying the security requirement of 3D graphics acceleration system,this method can reduce the computation and the costs of system resource.Thus it can meet the requirement of practical application.Nowadays,domestic researches on graphics concentrate on the field of multi-media technology,architectural design software,and so on,and researches in 3D graphics acceleration technology are still very limited.Design of high performance embedded 3D graphics acceleration systems is of great significance to enhance the level of our embedded industry,the international competitiveness,and the development of national defense.