Design And Implementation Of File Management System For Space-borne Solid State Recorder

With the development of national space industry,space-borne solid-state recorder NAND Flash-based is faced with large capacity,high speed,multi-task,multi-payload and other requirements.Currently,the space-borne solid-state recorder also uses traditional scheme of fixed partition based on storage block address ring queue sequential storage to achieve the payload data storage,playback and erasing and other functions.In the traditional storage management scheme,the coupling between hardware and software is strong,and the portability of software code is poor,and it can not effectively deal with the challenge of space-borne solid-state recorder of different mission.In this paper,we propose a file management system software architecture of spaceborne solid-state recorder based on NAND Flash file system scheme.The blocks of unused,invalid and payload are respectively linked together,forming the storage block list structure of files.Object-oriented synthetic design pattern is employed to realize tree directory structure in the file management system,with which,appropriate system initialization program would be chosen according to the state of system power-off.After the verification of normal power off or abnormal system power off,the file system could soon start-up.The software replays one payload file to the ground support equipment as it polling all payload directory.The software also adopts water level method,monitoring the remaining capacity in real time and deleting the condition matched files.Compared to the traditional bad block replacement algorithm,an algorithm of file-based bad block management,four-level pipeline ping-pong buffer mechanism is adopted,and it overcomes the drawback of solid-state recorder rate jitter.The hierarchical file management system software architecture,is of benefit to hide the underlying hardware and software interaction details and provide the file operation interface for the upper layer.Thus,the hardware and software is coupled loosely and the portability of software system gets improved.