Based On Flash Embedded File System

The traditional usage of embedded sytem is in autocontrol field, therequirement of date storage is not high, so people don't pay enough importance tothe filesytem of embedded operation system. But with the development of theembedded technology and more wildly use of embedded system, we need morestorage ability and more flexible method to control date and high reliability of datestorage. For this reason, it's necessary to use filesystem in embedded system, it canprovide interface to accesse and store date through the name of the file, which canprovide the function of date storeage and file management.The embedded filesystem inherit the design idea and implement method ofgeneral file system, furthermore, according to the characters of the embeddedsystem, we simplify it and change some point to adapt to the specific requirement.Form the point of embedded system, we should take these factors into account, asthe power consume, the reliability, the vol. and so on. There are many storagedevice just as Flash memory and Disk on chip, its ability is more than enough andits price is low, it has obvious advantage in embedded field, it has been wildly used.With the change of storage device we should do some following change to thefilesystem.Filesystem is the first external layer of operation system. If we need thefilesytem can be common used, we design the filesystem as a component of the OS,in the way there is lower coupling between OS kernel and filesystem component. Ifthe system used in scurviness surrounding, the date reliability must be ensured.Base on the requirement of reliability, we do some work to promote the filesytem'sreliability, through the software and hardware method. We take some technology asfollowing to impove filesystem's reliability, the CRC date check, the log file foritself, the balance wearing garbage collection, the power potect and using powerprotect chip.