Research And Implementation Of Cortex-A8 Processor-Based Embedded Intelligent Security Terminal

Embedded terminals and other mobile devices, as a major carrier of embedded technology has been fully integrated into our daily lives. Its powerful features and broad prospects have made this area a hot topic in recent years. On the other hand, openness and flexibility embedded platforms has brought great security risk to the user's information security. How to ensure the credibility of embedded devices has become an urgent problem.This paper focused on the functional requirements of embedded devices, and has proposed a design scheme based on Cortex-A8 + Android embedded intelligent terminal and expanded specific implementation process from the hardware and software aspects. Hardware aspect: select S5PV210 chip as the main CPU of hardware system, design and implement embedded terminal hardware systems according to the chip circuit theory, including the core module circuits and peripheral function module circuit. Software aspect: on the basis of complete software development environment, U-Boot, Android kernel and Android 4.0 platform have been analyzed, cut, compiled and transplanted respectively. After deeply understanding of the basic concepts and framework level of Android system driven, the sensor system at all levels has been analyzed, from the top Android Java applications to the underlying hardware layer structure. Gyro sensor hardware drivers have been developed based on input subsystem I~2C device, character device and input driver framework. Android 4.0 sensor hardware abstraction layer code has been modified and gyro sensor driver was completely transplanted.Finally, we focus on the technical contents which are related to trust computing. And a trusted security solution was proposed for the safety of embedded platforms. A hybrid chain of trust structure, including dual-boot mode and core root of trust measurement based on removable storage media, was introduced to reduce the distance between each node to the root node, which using pre-computed summary method to measure the node integrity. This paper also has simplified and transplanted the Trusted Software Stack and a trusted network access mechanism. Experimental results show that the program can detect whether the startup code has been tampered. And the time overhead has decreased 15.8% comparing to ordinary credible start. Sealing and unsealing applications also have ensured the security of important documents data. The credible security embedded terminal has been realized eventually.