File system FAT (file allocation table) partition table management method based on NOR FLASH

Abstract

The invention provides a file system FAT (file allocation table) partition table management method based on NOR FLASH, which is characterized in that a region in NOR FLASH is allocated and is used as an FAT partition table management region, the region is further divided into two parts, i.e. an FAT partition table index region and an FAT partition table region, wherein the FAT partition table region can be used for storing a plurality of FAT partition tables, firstly the region in the NOR FLASH is allocated and is used as the FAT partition table management region, the FAT partition table management region comprises the FAT partition table index region and a plurality of FAT partition tables, a current valid FAT partition table is obtained according to an index number in the FAT partition table index region, the FAT partition table next to the current valid FAT partition table is only required to be erased when the FAT partition table is required to be modified for file operation, and index numbers in the FAT partition table index region are cyclically increased.

Description

technical field [0001] The invention relates to the field of embedded terminals, in particular to a management method based on a NOR Flash file system FAT partition table. technical background [0002] With the development of embedded terminal technology, a variety of applications continue to appear, and most of the applications are accompanied by the processing and storage of a large amount of data. NOR Flash is generally used as the storage medium for embedded storage. The traditional data storage method is to specify Flash as the storage medium. The starting address and length, and the specified length must be a multiple of the size of the Flash erasing block, so as to avoid multiple data appearing on a Flash erasing block, thereby avoiding the risk of data being destroyed. The method of specifying the start address and length of Flash has two disadvantages: first, data expansion is not flexible, if a new application appears, the data of the new application needs to be sa...

AI Technical Summary

Problems solved by technology

The method of specifying the start address and length of Flash has two disadvantages: first, data expansion is not flexible, if a new application appears, the data of the new application needs to be saved, and an area must be re-allocated for the new data in the program; second , a waste of Flash space, NOR Flash erase blocks are generally 64K, for a class of data with only a few bytes, it is also necessary to allocate 64K space, which will cause a waste of Flash space

However, the traditional file system only has a single FAT partition table, and the partition table modification is directly modified on the basis of the original partition table. This method is not suitable for NOR FLASH storage media, because the characteristics of NOR FLASH need to erase the entire block first, and then Write, if the system is powered off during the erasing process, the entire partition table data will be lost and cannot be recovered

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