Design And Realization Of Virtual Device In Embedded System

The embedded system has been widely used in various fields,industry and application scenarios are associated with an embedded system is more and more,the demand for software and hardware standards stricter,hardware is need to have have been in progress of computing power,in addition to the types of external devices have become much more,The software needs to realize more complex functions that are different from the original,which leads to high cost in the development process of embedded products.Combined with embedded products in the process of the test would need a lot of hardware equipment and the specific field,and physical devices need bigger costs,and through the production,processing,assembly,test,and other links to consign is used,in the end to the limited number of research and development and testing equipment,in general it is not enough to use,In order to reduce the influence of this objective factor on software development and tester's development and testing,a virtual device is designed for its development and testing.At present,there are many kinds of virtualization technology products in the embedded field.The virtualization device simulation platform designed in thesis is built by using the virtualization platform QEMU.QEMU is an open source virtualization technology product with the advantages of cross-platform,high speed and portability.The virtualization device simulation platform also uses KVM acceleration technology to accelerate the CPU and memory of the simulated processor directly using the hardware resources of the host computer,so that its performance can reach the level of the physical machine.Then the realization of the virtual device should use the relocation shared library technology to simulate the peripheral hardware of the device simulation platform,shield some specific hardware access operations,so that the upper software does not perceive the loss of hardware,solve the problem of logic simulation of hardware functions,and implement the hardware data results expected by the upper software from the software level.Final experimental implementation in virtualization platform normal simulation of the CPU processor and memory,and so on,can realize the operation of the virtual platform,virtual equipment can normal operation in the simulation platform,can do some real equipment run time has the basic function,also can complete the communication between the virtual equipment,make the equipment can be normal access to the Internet,Test personnel can easily manage the device through the NETWORK management system,and r?d personnel can debug service functions without restrictions on the device.However,hardware virtualization for some special function chips may not be realized at present,only the expected results of the above layer can be returned to achieve the realization of specific business functions.The future research direction is to simulate the specific chip in the device,simulate the behavior of the chip with special functions,and make the virtual device more close to the real device.