CN110389853B

CN110389853B - Protection and recovery method for embedded file system

Info

Publication number: CN110389853B
Application number: CN201910559628.8A
Authority: CN
Inventors: 陈超鑫; 汤可; 范律; 肖林松
Original assignee: Willfar Information Technology Co Ltd
Current assignee: Willfar Information Technology Co Ltd
Priority date: 2019-06-26
Filing date: 2019-06-26
Publication date: 2024-01-02
Anticipated expiration: 2039-06-26
Also published as: CN110389853A

Abstract

A protection and recovery method of an embedded file system comprises the following steps: after the embedded system is powered on and reset, initializing system related and peripheral hardware; b, detecting whether the Mount operation in the Mount area is successful; whether the data is effectively detected in the DBR area, the FAT area and the DIR area; the system executes formatting to the Mount area; re-partition formatting the DBR area, the FAT area and the DIR area, and executing recovery parameter operation by the system after the partition formatting is successful; the system operates normally. The protection and recovery method for the embedded file system provided by the invention enters the protection measures from the Mount area after the system is electrified, in order to ensure the accuracy of the system operation, the data accuracy of the DBR area, the FAT area and the DIR area is detected, corresponding recovery operation is adopted, the normal operation of the system is ensured from the perspective of the system data accuracy, which cannot be considered by the person skilled in the art, and the protection of the embedded file system is greatly improved.

Description

Protection and recovery method for embedded file system

Technical Field

The present invention relates to the field of embedded systems, and in particular, to a method for protecting and recovering an embedded file system.

Background

So far, with the development of Cortex M0, M0+, M3, M4 and M7ARM core technologies, more chips are designed by using Cortex M cores as CPU cores, and more Cortex M core series chips are used by various manufacturers. Because of the limitation of chip area of Cortex M core series, RAM and ROM carried in the chip are not large, and are generally designed between tens of K and 1M. However, the application tasks running on the application tasks are more and more complex, the functions are more and more powerful, the data required to be processed are also obviously increased, and higher requirements are put on the management of various data. In order to enhance management of system-related data, support for the file system has to be sought. The importance of the file system as the sole component of embedded system data management is self-evident.

Currently, there are FatFs, uCFs, tinyFs, littleFs file systems that can run on small memories, and other large file systems can hardly be transplanted to small memory MCUs. However, the design of each file system does not fully consider the size of the memory space, the operation efficiency is not high, and many functions are not perfect. After the file system is truly transplanted to a Cortex M series chip, a series of problems are found in use, and the problems are mainly expressed as follows:

the embedded file system does not support power-down protection. Since Flash itself has its internal cell design properties that determine it can only be changed from 1 to 0 (discharge) and not from 0 to 1 (charge) for a single memory cell. An erase command from 0 to 1 can only be provided by Flash and operate on a block basis. Therefore, when writing Flash, the contents in a block are generally copied out entirely, then the block is erased, and finally the contents to be modified are written in the block according to pages. A block is typically designed to be 4K, 8K, 16K or more, and there may be a lack of erase to completely or only a portion of it is erased, or it may be that some data may not be written or written later on due to random power loss during erase, which may result in a large amount of data loss. The lost important data can affect the operation of the system, if the FAT table or the DIR table is lost, a considerable number of files are lost and cannot be read normally again, so that serious errors are generated, and the system is catastrophic.

The embedded file system does not support partition automatic detection, and cannot judge whether the FAT table or the DIR area is damaged or partially damaged. The result is that the damaged file system is still running erroneously and cannot be found and measures taken in time to restore to the last normal running state. The consequence of continued operation is that the system suffers from unpredictable errors.

The application document with the application number 201711497600.3 discloses a method for realizing a lightweight embedded file system, which is just a process for identifying whether data is legal or not, and does not disclose how to protect and recover effective data of the embedded file system.

Therefore, the protection and data recovery methods of the existing embedded systems are still to be improved and enhanced.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a protection and recovery method for an embedded file system, which can quickly determine whether corresponding data is damaged at the beginning of a system start, and if so, automatically perform a parameter recovery operation, so as to effectively ensure that the file system does not run an erroneous file.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a protection and recovery method of an embedded file system comprises the following steps:

A. after the embedded system is powered on and reset, initializing system related and peripheral hardware;

B. c, detecting whether the Mount area operation is successful, if so, executing the step C; if not, executing the step D;

C. f, whether the data of the DBR area, the FAT area and the DIR area are effectively detected, if yes, executing the step F; if not, executing the step E;

D. the system executes formatting to the Mount area, and after the formatting is completed successfully, the system executes the step B; if the formatting is not completed successfully, prompting error information;

E. b, re-partition formatting the DBR area, the FAT area and the DIR area, and executing a parameter recovery operation and a step C by the system after the partition formatting is successful; if the partition formatting and/or recovery parameter operation is not successful, prompting error information;

F. the system operates normally.

The preferred protection and recovery method of the embedded file system, wherein the step C further includes the step C': if the DATA of the DBR region, the FAT region and the DIR region are valid, detecting whether the DATA of the DATA region is valid, and if yes, executing the step F; if not, executing the operation of recovering the parameters.

The preferred protection and recovery method of the embedded file system, the recovery parameter operation specifically comprises the following steps:

e1, reading file backup/recovery record information in a bare area;

e2, reading file record head information;

e3, reading file record data;

e4, checking whether the recorded data and the backup/recovery recorded information are legal or not, and if yes, executing a step E5; if not, executing the step E6;

e5, generating a corresponding file in the partition according to the recorded file name, and checking whether the corresponding file is normal or not, if so, executing the step E6; if not, executing the step E4;

e6, checking whether all files are restored, if yes, setting a system file backup restoration record, and executing the step F; if not, executing the step E3.

Preferably, the protecting and recovering method of the embedded file system, step E further includes the steps of: and E0, backing up all default parameters/real-time parameters to the bare area.

Preferably, the method for protecting and recovering an embedded file system, the recording head information includes: file name, file length, and CRC check of the file;

the legal status obtained by the verification in the step E4 refers to: reading file record head information, reading file record data according to the file length, performing CRC (cyclic redundancy check) on the data, and comparing the calculated CRC with the CRC in the file head information to obtain a state that the information data are consistent.

The preferred method for protecting and recovering the embedded file system further comprises the following steps:

G. the system detects whether power is lost in real time, if yes, the system executes a power-down protection mode; if not, executing the step F.

Preferably, the protecting and recovering method of the embedded file system, the step G includes:

g1, detecting whether the system is powered down or not at a preset frequency, if so, executing a step G2; if not, executing the step F;

g2, saving intermediate data generated in the system operation, generating a power-down record, and setting a system power-down mark;

g3, stopping initiating new write operation, if the write operation in execution exists in the system, delaying the appointed time, waiting for all write operations to be completed, and if so, executing the step G4;

g4, enabling Flash to enter a write-protection state;

g5, operating with the power supplied by a standby power supply, detecting whether the system is electrified or not at the same time at a preset frequency, if so, removing the Flash write-protection state, and executing the step F; if not, waiting for the power consumption of the standby power supply, and completely powering down the system.

Preferably, in the step G3, the method further includes: and stopping initiating new read operation, and if the read operation in execution exists in the system, stopping the read operation in execution, and displaying the power-down information of the system.

Preferably, in the protection and recovery method of the embedded file system, the standby power supply is a capacitor or a battery.

The protection and recovery method of the embedded file system is preferable, and the designated time is 50-100ms; the predetermined frequency is 50-100Hz.

A preferred system for applying the method comprises:

the detection module is used for detecting the validity of system data;

and the recovery module is used for recovering the system data.

The system comprises a detection module, a detection module and a comparison detection unit, wherein the detection module comprises a mounting detection unit used for judging whether mounting in a Mount area is successful or not, and the comparison detection unit is used for detecting whether data are effective or not.

The system also comprises a power-down protection module for protecting the system after the system is powered down; the detection module further comprises a power failure detection unit for detecting whether the system is powered down.

A preferred device for applying the system comprises:

UPDATE area: establishing an upgrade file and control information by the partition last 4K;

PARAM region: default parameters/real-time operating parameters storage partitions;

LOG region: recording information generated by powering on and powering off a terminal, parameter damage and a system module;

RTTAPP zone: the data required by each task of the storage system are gathered;

RAW area: the system is directly managed through the address, and the data required by the system operation is saved in a record form.

Compared with the prior art, the protection and recovery method for the embedded file system provided by the invention has the advantages that after the system is powered on, protection measures are taken from the Mount of the Mount area, in order to ensure the accuracy of the system operation, the data accuracy of the DBR area, the FAT area and the DIR area is detected, corresponding recovery operation is adopted, the normal operation of the system is ensured from the perspective of the system data accuracy, and the protection of the embedded file system is greatly improved, which cannot be expected by the person skilled in the art.

Drawings

Fig. 1 is a start-up flowchart of the protection and recovery method provided in the present application.

Fig. 2 is a flowchart of a parameter recovery operation provided in the present application.

Fig. 3 is a power-down protection flowchart provided in the present application.

Detailed Description

The invention provides a protection and recovery method of an embedded file system, which aims to make the purposes, technical schemes and effects of the application clearer and more definite, and further details of the application are described below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

Example 1

Referring to fig. 1, the present application provides a method for protecting and recovering an embedded file system, which specifically includes:

s10, after the embedded system is powered on and reset, initializing system related and peripheral hardware;

s20, detecting whether the Mount area operation is successful, if so, executing a step S30; if not, executing step S40;

s30, whether the data of the DBR area, the FAT area and the DIR area are effectively detected, if yes, a step S60 is executed; if not, executing step S50;

s40, the system executes formatting on the Mount area, and after the formatting is completed successfully, the system executes a step S20; if the formatting is not completed successfully, prompting error information;

s50, re-partition formatting is carried out on the DBR area, the FAT area and the DIR area, after the partition formatting is successful, the system executes the operation of recovering parameters, and the step S30 is executed; if the partition formatting and/or recovery parameter operation is not successful, prompting error information;

s60, the system operates normally.

And after the embedded file system is powered on and reset, carrying out the mounting initialization of the embedded file system and each partition. And firstly, carrying out Mount (command, mount file) operation on the file system partition, and formatting the partition to be mounted if the partition is not successfully mounted for a plurality of times. After successful mounting, the validity of the DBR (DOS BOOT Record ) area, the FAT (File Allocation Table, file configuration Table) area and the DIR (Directory) area is detected. If the DBR region, the FAT region and the DIR region are found to be abnormal, formatting and parameter recovery operations are carried out on the DBR region, the FAT region and the DIR region, so that all operation parameters of the system in the operation starting stage can be ensured to be effective and all original data operated last time, abnormal data caused by accidents can not be operated, and the stability of the system is greatly improved.

In specific implementation, the starting positions and sizes of the DBR region, the FAT region and the DIR region on the flash (Flash EEPROM Memory, flash memory) are shown in the following table:

partition name	Partition size	Partition address range
			DBR region	0.5KB	0x000000～0x0001FF
FAT area	60KB	0x000200～0x00F1FF
			DIR region	16KB	0x00F200～0x0131FF
DATA region	14.8MB	0x013200～0xEDFFFF

The starting position and the size of the partition on the file system are shown in the following table:

partition name	Partition start sector	Partition size sector
			DBR region	b_dbr＝0	n_dbr＝1
FAT area	b_fat＝1	n_fat＝120
			DIR region	b_dir＝121	n_dir＝32
DATA region	b_data＝153	n_data＝7578

The first part of the partition is the DBR section, the FAT section and DIR section, and finally the DATA section where the file contents are actually stored. The format function f_format () calculates the start position of each region, and the size of each region, inside according to the space size allocated by the partition. After the FAT area or DIR area is formatted, the file system writes the relevant mark in each area and clears all the designated areas to 0x00 as required.

In practical application, the damage of the data in the FAT area and the DIR area may cause that the directory and the files of the file system cannot be read and written correctly, and the damage of the whole partition may be caused when serious. After the system is powered on, all information of the DBR area, the FAT table, the DIR area, the starting position, the size, the partition type and other partitions are read from the formatted partition through the f_mount () function and used for partition effectiveness detection.

During the use of the file system, sector allocation is performed in the relevant area, and specified data is written in the relevant area as required. The case where the entire Sector is all 0xFF does not occur. If the entire Sector is all 0xFF, then the Sector is considered erased and/or unwritten, or written with random data. If the FAT table and directory area together have more than a specified number of sectors all 0xFF, then the FAT table or directory is considered to have been corrupted. The system detects the starting position and the size of the DBR area, the FAT table and the DIR area, and if the starting position and the size exceed the specified values, the partition is considered to be damaged. If the system detects the damage of the partition, f_mkfs () is called to format the partition, and then the Mount operation is performed again.

Example 2

Preferably, the present application further provides a scheme that step S30 further includes step S30' (not shown): if the DATA in the DBR area, the FAT area, and the DIR area are valid, detecting whether the DATA in the DATA area is valid, if so, executing step S60; if not, executing the operation of recovering the parameters.

The DATA in the DATA field, if not verified successfully, can also cause various problems with the system, leading to unpredictable operational errors. Therefore, the damage to the partition is judged, the formatting operation is performed when the damage occurs to the partition, and the parameter recovery operation is performed when the damage occurs to the DATA area. If the parameter area is damaged, the system can call prm_ret_files () to restore parameters, so that the normal parameters required by the system are ensured, and the normal operation of the system is ensured.

Referring to fig. 2, in the above embodiment, the recovery parameter operation specifically includes the following steps:

s51, reading file backup/recovery record information in a bare area;

s52, reading file record head information;

s53, reading file record data;

s54, checking whether the recorded data and the backup/recovery recorded information are legal or not, and if yes, executing a step S55; if not, executing step S56;

s55, generating a corresponding file in the partition according to the recorded file name, and checking whether the corresponding file is normal or not, if so, executing the step S56; if not, executing step S54;

s56, checking whether all files are restored, if yes, setting a system file backup restoration record, and executing a step S60; if not, step S53 is performed.

The specific operation is as follows:

parameter backup: before the product leaves the factory, prm_bak_files () is required to be called to backup all default parameters to a bare area; in the running process of the system, the real-time parameters generated by the system confirmed by the user or the system can also call prm_bak_files () to be backed up to the bare area. For example, in the running process, as long as parameter modification is issued by the master station, corresponding parameter backup is required for infrared, USB flash disk upgrade and the like, and prm_bak_onefile () is called to carry out single parameter backup. Ensuring the real-time synchronization of the parameters of the backup area and the parameter area, and keeping up to date;

storage of parameters in the bare area: the first 4K of the bare area stores backup/restore record information (32 bytes), backup and restore marks, and backup and restore times. The first 32 bytes of each parameter are header information: file name, file length, file CRC (Cyclic Redundancy Check ) check, each file content is deposited starting from byte 32 of header information. Storing real-time parameters from 4K, distributing 16K to each real-time parameter, and storing factory default parameters after the real-time parameters are stored;

parameter recovery is based on: if the system detects that the system parameters are damaged, firstly reading file backup and recovery record information, and confirming whether the bare area is backed up or not. If the bare area has backup, the file record head information is read, which mainly comprises file name, file length and file CRC check. And reading file record data according to the file length, performing CRC (cyclic redundancy check) on the data, and comparing the calculated CRC with the CRC in the file header information. And then generating a corresponding file in the partition according to the recorded file name, and checking whether the file generated in the partition is normal or not by the system. Next, carrying out next file recovery, and setting relevant information of system file recovery records after all files are recovered, wherein the whole recovery work is completed;

in the above operation, the record structure of the file backup and recovery is as follows:

the information structure of the file is as follows:

in an actual implementation, the 16M Spi Data Flash partition map of the system is as follows:

UPDATE: and the upgrading area is used for a transfer station for upgrading files in serial ports, USB and remote. The last 4K of the partition establishes an upgrade file and control information, such as upgrade or not, upgrade file length, verification, time mark and the like.

PARAM: and the parameter area, the file system supports reading, leaving the default parameters, and storing the real-time running parameters in the partition.

LOG: the log area, the file system support reading, the black box of the terminal, and record the powering on and powering off of the terminal, parameter destruction and various important information generated by the system module.

RTTAPP: the data area, the file system supports reading, and the data required by each task of the system are gathered.

RAW: the parameter backup area, the bare area, the unsupported file system, is directly managed by the system through the address, and saves important data required by the system operation in a record form. When the data partition is destroyed, the data needs to be copied from the RAW parameter backup area to generate a corresponding file.

Example 3

Referring to fig. 3, preferably, the present application further provides a power-down protection operation, and the method for protecting and recovering an embedded file system further includes the steps of:

s70, detecting whether power is lost or not in real time by the system, and if so, executing a power-down protection mode by the system; if not, step S60 is performed.

The step S70 includes:

s71, detecting whether the system is powered down or not at a preset frequency, if yes, executing a step S72; if not, executing step S60;

s72, saving intermediate data generated in the system operation, generating a power-down record, and setting a system power-down mark;

s73, stopping initiating new write operation, if the write operation in execution exists in the system, delaying the appointed time, waiting for all write operations to be completed, and if so, executing the step S74;

s74, enabling Flash to enter a write-protection state;

s75, using a standby power supply to supply power for running, detecting whether the system is electrified or not at the same time at a preset frequency, if so, removing the Flash write-protection state, and executing the step S60; if not, waiting for the power consumption of the standby power supply, and completely powering down the system.

In actual operation, the system operates normally, and whether the system is powered down is detected at a predetermined frequency. If the system is powered down, the system can quickly identify and react. The file that needs to be written or is being written, the system allows it to be written in Flash in its entirety. After the writing is finished, the system does not initiate new writing operation any more, and after the specified time is delayed, flash writing protection is opened, so that the Flash enters a writing protection state, and the file system is prevented from being damaged.

In summary, the protection and recovery method for embedded files provided by the present application starts to detect the accuracy of data when the system is started, and after detecting the data abnormality, can solve the corresponding problem in a targeted manner, so as to avoid the system abnormality caused by the system operation error data, and the focus of the person skilled in the art is on the abnormal data generated in the system operation or the abnormal operation, so that the present application is a technical scheme for guaranteeing the accuracy of the system data from the beginning of the system operation, which is not thought of by the person skilled in the art and does not take the corresponding scheme.

It will be understood that equivalents and modifications will occur to persons skilled in the art and may be made in accordance with the present invention and its application and spirit, and all such modifications and substitutions are intended to be included within the scope of the following claims.

Claims

1. The method for protecting and recovering the embedded file system is characterized by comprising the following steps:

the step C further comprises the step C': if the DATA of the DBR region, the FAT region and the DIR region are valid, detecting whether the DATA of the DATA region is valid, and if yes, executing the step F; if not, executing the operation of recovering the parameters;

F. the system operates normally;

the method also comprises the steps of: G. the system detects whether power is lost in real time, if yes, the system executes a power-down protection mode; if not, executing the step F;

the step G comprises the following steps:

g4, enabling Flash to enter a write-protection state;

2. The method for protecting and recovering an embedded file system according to claim 1, wherein the recovering parameter operation specifically comprises the following steps:

e1, reading file backup/recovery record information in a bare area;

e2, reading file record head information;

e3, reading file record data;

3. The method for protecting and recovering an embedded file system according to claim 2, wherein the step E further comprises the steps of: and E0, backing up all default parameters/real-time parameters to the bare area.

4. The method for protecting and recovering an embedded file system according to claim 2, wherein the recording head information comprises: file name, file length, and CRC check of the file;