Based On The Research And Design Of Embedded Wireless File System

This thesis discusses the multi-user mode and dedicated file transfer system of theembedded wireless devices in depth, which is to improve and achieve the file transfersystem based on dedicated wireless embedded devices. The thesis mainly discusses theproblems, including the custom cutting and transplanting the embedded operatingsystems, loading the driver, building a wireless networking platform and optimizing theimprovement of the file transfer system with limited hardware resources to improvesystem stability, security, and efficiency. This thesis mainly discusses about the generalembedded devices, and the design idea is apply to the universality of application, andthe code is portability.This thesis designed the adaptive dynamic optimization thread pool for themulti-threaded programming. The thread task scheduling mode is optimized to improvesystem efficiency. Design the thread synchronization and deadlock preventionoptimization and the condition and mutexes variables were used in conjunction for thethread pool management and the critical resource protection. Design the system linkedlist to achieve the unity of the linked list in application and management, in themeantime, the program code size and program complexity were reduced. In order toensure the perfection functions of the system, we give the waiting queue and the timeoutthread. The pipeline signaling mechanism of the Linux operating system and quitunexpectedly push function to the design of mechanisms to deal with unplanned outageswere used for stability of the system. Analysis the TCP/IP protocol, we put forward asingle packet of the handshake, massive data flow program to solve the adhesionproblems of TCP/IP packets. We use the RSA encryption algorithm to encrypt thetransmit data, optimize the MD5cipher text for the user information security, anddesign the file integrity verification based on the MD5algorithm.we also extend thefunction of file permissions based on file attributes bit of the linux system.The techniques all above, which made the system have a10-30%increase in accessefficiency than the traditional multi-threaded design. The design of the system linkedlist reduces about20%in the amount of code and the complexity of the program design. The handling mechanism of the unexpected system interrupt improves the stability ofthe system. The RSA encryption algorithm is used to ensure the security of the datatransfer, and the improved MD5cipher text algorithm improves the security of userinformation. Also, the file system function has been extended to achieve waitingtime-out and the file permissions management functions. The extended file systemfunctionality to achieve waiting time-out and file permissions management functions.