File management system in small storage space

Abstract

The invention discloses a file management system in a small storage space. The file management system comprises a file creating unit, a file deleting unit, a file operating unit and a file storage space managing unit, wherein the file creating unit comprises a file creation safety condition judging operation, a file space application operation, a file registration operation and a file control information writing-in operation and is used for realizing the distribution of file space against different file categories and writing-in of file control information; the file deleting unit comprises safety state judgment and file logic deletion and can realize the deletion of a file application and simultaneously retain the continuity of the file system; the file operating unit comprises file selection, data saving, data reading, data modification and a file reading and writing operation and can realize selection, saving, reading and modification of a file and control the access of the file; and the file storage space managing unit comprises file space distribution and file operation boundary management and can realize the file operation boundary control and prevent a cross-border operation during the file operation process.

Description

technical field [0001] The invention relates to a file management system, in particular to a file management system for small storage space in the field of smart card operating systems. Background technique [0002] Smart Card (Smart Card) is a general term for a plastic card embedded with an integrated circuit chip. According to the type of embedded chip, IC card can be divided into three categories: memory card, logic encryption card and CPU card, but only CPU The card is the real smart card. The integrated circuit in the smart card (CPU card) includes a central processing unit (CPU), a programmable read-only memory EEPROM, a random access memory RAM, and a card operating system COS (Chip Operating System) solidified in the read-only memory ROM. A microcontroller (MCU) with CPU, memory and peripherals acts as the overall control unit of the smart card. [0003] The operating system (Chip Operation System, COS for short) of the smart card is the core technology of the sma...

AI Technical Summary

Problems solved by technology

[0006] 1. There is no file management method specifically for small storage spaces. The existing file management methods mainly include FAT, NTFS, etc. or simplified or extended file management methods based on these file management methods. These management methods cannot be well applied to small storage space. Storage space, especially about 32KB storage space similar to the smart card field

[0007] 2. The file management of the small storage space in the smart card field is not specific to the characteristics of the smart card field. From the perspective of the operating characteristics of the smart card, the file system of the smart card is generally created before personalization, and the entire life cycle rarely needs to be expanded. Create files, delete files and other operations, from the perspective of the hardware characteristics of smart cards, smart cards have requirements for the amount of code, which generally cannot exceed 32KB, which conflicts with the ever-expanding applications

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