IAP upgrading method based on multi-stage CRC verification

Abstract

An IAP upgrading method based on multi-stage CRC verification comprises a firmware downloading stage, a firmware copying stage and an application starting stage, and specifically comprises the following steps that CRC verification is carried out in the firmware downloading stage; performing CRC (Cyclic Redundancy Check) in the firmware copying stage; and performing CRC (Cyclic Redundancy Check) in the application starting stage. Through multi-stage CRC verification, a more comprehensive verification process is provided, and correctness and integrity in the firmware upgrading process are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of single-chip microcomputer software upgrade, and in particular to an IAP upgrade method based on multi-stage CRC verification. Background Art

[0002] The IAP upgrade technology of STM32 is a function that allows the microcontroller to receive new firmware and update itself through a specific communication interface during operation, that is, to update the STM32 firmware through software methods without using an external programmer. Usually the flash memory of STM32 is divided into two areas, one for running the current application and the other for storing new firmware. When the system starts, the Bootloader checks whether it needs to enter the upgrade mode, which is usually achieved by monitoring the status of specific pins or specific communication commands. If an upgrade is required, the update program is received. The received data is usually stored in RAM first, and then written to the specified area of ​​the flash memory. The update program can be run after powering on again. Using IAP upgrade, the firmware can be updated during the use of the product without returning to the factory, saving costs.

[0003] The existing IAP upgrade method has certain limitations, and the correctness of the firmware upgrade cannot be reliably guaranteed. For example, patent CN116302012A discloses an alternating IAP upgrade system and method, which adds file verification during the process of sending bin files from the upper computer to the lower computer via CAN communication, and lacks verification of the process of copying files from the RAM area to the FLASH; patent CN112579130B discloses an interactive IAP upgrade method, which verifies the upgrade package after the device to be upgraded receives the upgrade package, and only includes the firmware download stage. Both of them perform single-stage verification on the firmware upgrade, and the reliability is low.

[0004] At the same time, the existing IAP upgrade method lacks host authentication during IAP upgrade, and the firmware source cannot be verified, which poses a security risk; the entire firmware is transmitted each time during IAP upgrade, resulting in a relatively long transmission and writing time, which greatly reduces the upgrade efficiency. Summary of the invention

[0005] Based on this, it is necessary to provide an IAP upgrade method based on multi-stage CRC verification. By performing multi-stage CRC verification and digital signature verification, a more comprehensive verification process is provided to ensure the correctness, integrity and security of the firmware upgrade process. Combined with differential upgrade technology, only the changed part of the firmware is transmitted, which significantly shortens the upgrade time and improves the upgrade efficiency.

[0006] The first object of the present invention is to provide an IAP upgrade method based on multi-stage CRC check, including a firmware download stage, a firmware copy stage and an application startup stage, specifically including the following steps:

[0007] Performing CRC check during the firmware download phase;

[0008] Performing CRC check during the firmware copying phase;

[0009] A CRC check is performed during the application startup phase.

[0010] Furthermore, before the CRC check is performed in the firmware download stage, the following steps are also included:

[0011] The digital signature of the firmware is verified.

[0012] Furthermore, performing CRC check in the firmware downloading stage specifically includes:

[0013] dividing the firmware into a plurality of firmware data frames;

[0014] The host computer sends the firmware data frame to the device to be upgraded;

[0015] The device to be upgraded receives the firmware data frame and performs a CRC check on each firmware data frame;

[0016] Determine whether the CRC check is successful;

[0017] If the CRC check succeeds, proceed to the next step;

[0018] If the CRC check fails, the device to be upgraded stops receiving the firmware data frame and sends an error code to the host computer through the IAP interface.

[0019] Furthermore, performing CRC check in the firmware copying stage specifically includes:

[0020] The external memory of the device to be upgraded reads the firmware data frame, and copies the firmware data frame to the internal FLASH to obtain a copy data frame;

[0021] Performing CRC check after the firmware data frame is copied;

[0022] Determine whether the CRC value of the copied data frame is consistent with the CRC value of the firmware data frame;

[0023] If the CRC value of the copied data frame is consistent with the CRC value of the firmware data frame, executing the next step;

[0024] If the CRC value of the copied data frame is inconsistent with the CRC value of the firmware data frame, the copying is stopped.

[0025] Furthermore, performing CRC check in the firmware startup phase specifically includes:

[0026] Before the firmware is started, a CRC check is performed on the copied firmware;

[0027] Determine whether the CRC check is successful;

[0028] If the CRC check succeeds, the firmware is started;

[0029] If the CRC check fails, the application is prevented from starting the firmware, and the firmware is downloaded again.

[0030] Furthermore, the digital signature verification of the firmware specifically includes the following steps:

[0031] After the firmware is compiled, a hash value of the firmware image is generated by a hash function;

[0032] The hash value is encrypted according to a private key to generate a digital signature of the firmware; the firmware and its digital signature are transmitted together to the device to be upgraded;

[0033] The device to be upgraded receives the firmware and its digital signature, and decrypts the digital signature using a public key to obtain a decrypted hash value; at the same time, the device to be upgraded calculates the firmware image to obtain a new hash value;

[0034] comparing the decrypted hash value with the new hash value;

[0035] If the decrypted hash value is consistent with the new hash value, it is confirmed that the firmware has not been tampered with and the verification is successful;

[0036] If the decrypted hash value is inconsistent with the new hash value, it is determined that the firmware has been tampered with and the verification fails.

[0037] Furthermore, it also includes a firmware upgrade phase, the specific steps are as follows:

[0038] Identify the difference between the new firmware and the old firmware by using a binary difference algorithm, and generate a difference patch file; wherein the difference patch file contains the difference between the new firmware and the old firmware;

[0039] The firmware in the internal FLASH is upgraded through the differential patch file.

[0040] Furthermore, the firmware upgrade phase also includes the following steps: after the upgrade is completed, the upgraded firmware is checked for integrity. If the check is successful, the entire upgrade process is completed; if the check fails, the upgrade is performed again.

[0041] Further, upgrading the firmware in the internal FLASH through the differential patch file specifically includes:

[0042] Obtaining positioning information in the difference patch file;

[0043] The difference part is written into the corresponding area of ​​the old firmware according to the positioning information.

[0044] Furthermore, the device to be upgraded is STM32.

[0045] Compared with the prior art, the beneficial effects of this application are:

[0046] Through multi-stage CRC verification, a more comprehensive verification process is provided to ensure the correctness and integrity of the firmware upgrade process; digital signature verification technology provides a safe and reliable framework for firmware upgrades, and through the use of advanced encryption algorithms, the integrity and source verification of the firmware are ensured, thereby improving the security of the firmware upgrade process; through differential upgrade technology, differential patch files are generated, and only differential patches are transmitted, which greatly shortens the time required for firmware upgrades, improves the upgrade speed, and reduces system downtime caused by upgrades. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flowchart of an IAP upgrade method based on multi-stage CRC check according to an embodiment of the present invention;

[0048] Figure 2 A CRC check flow chart of the firmware download phase of an IAP upgrade method based on multi-stage CRC check according to an embodiment of the present invention;

[0049] Figure 3 A CRC check flow chart of the firmware copying phase of an IAP upgrade method based on multi-stage CRC check according to an embodiment of the present invention;

[0050] Figure 4 A CRC check flow chart of an application startup phase of an IAP upgrade method based on multi-stage CRC check according to an embodiment of the present invention;

[0051] Figure 5 A digital signature verification flow chart of an IAP upgrade method based on multi-stage CRC verification according to an embodiment of the present invention;

[0052] Figure 6The present invention is a differential upgrade flow chart of an IAP upgrade method based on multi-stage CRC check according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] like Figure 1 As shown, an IAP upgrade method based on multi-stage CRC check according to an embodiment of the present invention includes a firmware download stage, a firmware copy stage and an application startup stage, and specifically includes the following steps:

[0055] S1: Perform CRC check during firmware download stage;

[0056] IAP upgrade is a technical means to update, modify or expand the device's own firmware or program through software during the operation of the device. This upgrade method does not require an external programmer, but completes the firmware update through specific program logic and interfaces, greatly improving the convenience of the update.

[0057] CRC is a cyclic redundancy check that is used to detect errors in data transmission and ensure the integrity and accuracy of firmware data.

[0058] It should be noted that if Figure 2 , the CRC check during the firmware download phase specifically includes:

[0059] S101: dividing the firmware into a plurality of firmware data frames;

[0060] The firmware data frame includes a frame header, a data part and a frame trailer, wherein the frame header contains the frame sequence number and frame length information, the data part is the actual content of the firmware after being divided, and the frame trailer contains verification messages such as checksums, hash values, etc.

[0061] In this embodiment, the segmentation method can be to segment the firmware according to a preset fixed number of bytes or data block size. For example, the firmware can be segmented into a firmware data frame of 1024 bytes each. This ensures that the size of each firmware data frame is consistent, which is convenient for processing at the transmission and receiving ends.

[0062] In another embodiment, the segmentation method may also be to segment according to the actual structure of the firmware file to ensure that each data frame contains a complete logical unit.

[0063] S102: The host computer sends the firmware data frame to the device to be upgraded;

[0064] It can be understood that the host computer can be deployed in an X86 host or an ARM host of a Linux system, the device to be upgraded includes an IAP interface, a SWD interface and a chip, and the host computer communicates with the device to be upgraded through the IAP interface. In this embodiment, the device to be upgraded is STM32.

[0065] S103: The device to be upgraded receives the firmware data frame and performs a CRC check on each firmware data frame;

[0066] S104: Determine whether the CRC check is successful;

[0067] If the CRC check succeeds, execute S105;

[0068] If the CRC check fails, execute S106.

[0069] S105: Execute the next step;

[0070] S106: The device to be upgraded stops receiving firmware data frames and sends an error code to the host computer through the IAP interface.

[0071] In the present embodiment, in the firmware download stage, the present invention adopts a real-time CRC verification mechanism. When the firmware data frame is transmitted to the STM32 microcontroller via the IAP interface, the system will immediately perform a CRC check on each frame of data received. Ensure that possible errors are found in time during the data transmission process to avoid further processing of invalid data. Secondly, the firmware data is divided into multiple data frames, and CRC calculation is performed separately for each data frame, which improves the accuracy of the verification. If the CRC check fails, the system will immediately stop data reception, and send an error code to the host through the IAP interface, notify the host, and record the error information at the same time, which is convenient for subsequent analysis.

[0072] S2: Perform CRC check during firmware copying phase;

[0073] It should be noted that if Figure 3 , the CRC check during the firmware copy phase specifically includes:

[0074] S201: The external memory of the device to be upgraded reads the firmware data frame, and copies the firmware data frame to the internal FLASH to obtain a copy data frame;

[0075] S202: Perform CRC check after the firmware data frame is copied;

[0076] S203: Determine whether the CRC value of the copied data frame is consistent with the CRC value of the firmware data frame;

[0077] If the CRC value of the copied data frame is consistent with the CRC value of the firmware data frame, execute S204;

[0078] If the CRC value of the copied data frame is inconsistent with the CRC value of the firmware data frame, execute S205.

[0079] S204: Execute the next step;

[0080] S205: Stop copying.

[0081] In this embodiment, the firmware data frame is copied from RAM to the internal FLASH frame by frame. After each frame of data is copied, a secondary CRC check is performed to ensure that the data is not damaged during the copying process. The CRC value of the original firmware data frame is compared with the CRC value of the copied data frame. If they are inconsistent, it indicates that an error may have occurred during the copying process. The system will stop the copying operation, record the error information, and notify the host computer through the IAP interface for troubleshooting and data retransmission.

[0082] S3: Perform CRC check during application startup.

[0083] It should be noted that if Figure 4 , the CRC check during the firmware startup phase specifically includes:

[0084] S301: before the firmware is started, a CRC check is performed on the copied firmware;

[0085] S302: Determine whether CRC check is successful;

[0086] If the CRC check succeeds, execute S303;

[0087] If the CRC check fails, execute S304.

[0088] S303: Start the firmware.

[0089] S304: Prevent the application from launching the firmware, and re-download the firmware.

[0090] In this embodiment, the present invention performs a final CRC check on the firmware in the internal FLASH before the application is started to ensure the integrity of the firmware during the storage stage and to ensure that all data is correct. If the CRC check fails, the system will prevent the application from starting to avoid system crashes caused by firmware errors; at the same time, a firmware recovery option is provided to re-download the firmware.

[0091] This application provides a more comprehensive verification process through multi-stage CRC verification, ensuring the correctness and integrity of the firmware upgrade process.

[0092] It should be noted that before the CRC check during the firmware download phase, the following steps are also performed:

[0093] S4: Verify the digital signature of the firmware.

[0094] It should be noted that if Figure 5 , the digital signature verification of the firmware specifically includes the following steps:

[0095] S401: After the firmware is compiled, a hash value of the firmware image is generated by a hash function;

[0096] S402: Encrypting the hash value according to the private key to generate a digital signature of the firmware; transmitting the firmware and its digital signature together to the device to be upgraded;

[0097] S403: The device to be upgraded receives the firmware and its digital signature, and decrypts the digital signature using the public key to obtain a decrypted hash value; at the same time, the device to be upgraded calculates the firmware image to obtain a new hash value;

[0098] S404: Determine whether the decrypted hash value is consistent with the new hash value;

[0099] If the decrypted hash value is consistent with the new hash value, execute S405;

[0100] If the decrypted hash value is inconsistent with the new hash value, execute S406.

[0101] S405: confirm that the firmware has not been tampered with, and the verification is successful;

[0102] S406: It is determined that the firmware has been tampered with and the verification fails.

[0103] In this embodiment, before the firmware is released, the present invention adopts a digital signature process. First, after the firmware is compiled, the developer uses a hash function to generate a unique hash value for the firmware image. Then, the developer uses his private key to encrypt the hash value to generate a digital signature of the firmware. This signature will be distributed with the firmware as part of the firmware.

[0104] During the firmware upgrade process, STM32 separates the received firmware and its digital signature. Then, the digital signature is decrypted using the developer's public key to obtain the decrypted hash value. At the same time, the controller also performs the same hash calculation on the firmware image to generate a new hash value. By comparing the two hash values, if they are the same, it proves that the firmware has not been tampered with during transmission and the signature is valid.

[0105] Through digital signature verification, this application ensures that the firmware maintains integrity and consistency during the transmission process from the developer to the end user. Any tampering with the firmware will cause the hash value to change, causing the signature verification to fail, thereby effectively preventing the implantation of malicious code. Digital signature verification not only ensures the integrity of the firmware, but also verifies the source of the firmware. Since the private key is only held by the developer, only the developer can generate a valid signature. This prevents unauthorized third parties from publishing malicious firmware and ensures the security of user devices. The digital signature verification technology of the present invention provides a safe and reliable framework for firmware upgrades. It improves the security of the firmware upgrade process by adopting advanced encryption algorithms, providing algorithm flexibility, and ensuring the integrity and source verification of the firmware.

[0106] It should be noted that if Figure 6 , also includes the firmware upgrade phase, the specific steps are as follows:

[0107] S501: Identify the difference between the new firmware and the old firmware by using a binary difference algorithm, and generate a difference patch file; wherein the difference patch file contains the difference part between the new firmware and the old firmware.

[0108] The present invention uses a binary difference algorithm that can automatically analyze the differences between the new and old firmware. By comparing the new firmware and the old firmware byte by byte, the algorithm can accurately identify which data has changed in the new firmware version and which data remains unchanged. This difference identification process is fully automated and does not require manual intervention, greatly improving the efficiency of firmware upgrades.

[0109] After identifying the difference, the algorithm generates a differential patch file. This patch file contains only the difference between the old and new firmware, that is, the data that needs to be updated. Since it does not contain unchanged data, the size of the patch file is much smaller than the complete firmware image file, which greatly reduces the file size. Since the differential upgrade technology transmits the differential patch instead of the entire firmware image, the amount of data transmitted is significantly reduced. This reduction is particularly significant when the firmware version is updated frequently or the firmware size is large, which can save storage space. Since the amount of data transmitted is reduced, the time required for firmware upgrades is also shortened, which can increase the upgrade speed and reduce the system downtime caused by the upgrade.

[0110] S502: Upgrade the firmware in the internal FLASH through the differential patch file.

[0111] Wherein, S502: upgrading the firmware in the internal FLASH through the differential patch file specifically includes the following steps:

[0112] Get the positioning information in the difference patch file;

[0113] The difference part is written to the corresponding area of ​​the old firmware according to the positioning information.

[0114] The differential upgrade technology of the present invention can accurately apply the differential patch file to the corresponding position of the old firmware. The system will accurately write the changed data to the corresponding area of ​​the old firmware according to the positioning information in the differential patch file, thereby ensuring the accuracy of the firmware update.

[0115] S503: After the upgrade is completed, the upgraded firmware is checked for integrity. If the check succeeds, the entire upgrade process is completed; if the check fails, the upgrade is performed again.

[0116] By calculating the firmware checksum or using other verification mechanisms, it is ensured that no errors occur during the firmware upgrade process, thereby ensuring the integrity and normal operation of the firmware.

[0117] Since differential upgrade technology only updates the changed parts, it has lower compatibility requirements for old firmware and can be upgraded without changing the original system architecture. At the same time, it reduces the risk of data transmission errors and data corruption during the upgrade process and improves system stability.

[0118] Based on the above ideal embodiments of this application, the relevant staff can make various changes and modifications without departing from the technical concept of this application through the above description. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

[0119] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0120] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0121] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

Claims

1. An IAP upgrade method based on multi-stage CRC check, including a firmware download stage, a firmware copy stage and an application startup stage, characterized in that: The specific steps include: Performing CRC check during the firmware download phase; Performing CRC check during the firmware copying phase; A CRC check is performed during the application startup phase.

2. The IAP upgrade method based on multi-stage CRC check according to claim 1, characterized in that: Before the CRC check is performed in the firmware download stage, the following steps are also included: The digital signature of the firmware is verified.

3. The IAP upgrade method based on multi-stage CRC check according to claim 1, characterized in that: The CRC check during the firmware download stage specifically includes: dividing the firmware into a plurality of firmware data frames; The host computer sends the firmware data frame to the device to be upgraded; The device to be upgraded receives the firmware data frame and performs a CRC check on each firmware data frame; Determine whether the CRC check is successful; If the CRC check succeeds, proceed to the next step; If the CRC check fails, the device to be upgraded stops receiving the firmware data frame and sends an error code to the host computer through the IAP interface.

4. The IAP upgrade method based on multi-stage CRC check according to claim 3 is characterized in that: The CRC check during the firmware copying phase specifically includes: The external memory of the device to be upgraded reads the firmware data frame, and copies the firmware data frame to the internal FLASH to obtain a copy data frame; Performing CRC check after the firmware data frame is copied; Determine whether the CRC value of the copied data frame is consistent with the CRC value of the firmware data frame; If the CRC value of the copied data frame is consistent with the CRC value of the firmware data frame, executing the next step; If the CRC value of the copied data frame is inconsistent with the CRC value of the firmware data frame, the copying is stopped.

5. The IAP upgrade method based on multi-stage CRC check according to claim 4, characterized in that: The CRC check during the firmware startup phase specifically includes: Before the firmware is started, a CRC check is performed on the copied firmware; Determine whether the CRC check is successful; If the CRC check succeeds, the firmware is started; If the CRC check fails, the application is prevented from starting the firmware, and the firmware is downloaded again.

6. The IAP upgrade method based on multi-stage CRC check according to claim 2, characterized in that: The digital signature verification of the firmware specifically includes the following steps: After the firmware is compiled, a hash value of the firmware image is generated by a hash function; The hash value is encrypted according to a private key to generate a digital signature of the firmware; the firmware and its digital signature are transmitted together to the device to be upgraded; The device to be upgraded receives the firmware and its digital signature, and decrypts the digital signature using a public key to obtain a decrypted hash value; at the same time, the device to be upgraded calculates the firmware image to obtain a new hash value; comparing the decrypted hash value with the new hash value; If the decrypted hash value is consistent with the new hash value, it is confirmed that the firmware has not been tampered with and the verification is successful; If the decrypted hash value is inconsistent with the new hash value, it is determined that the firmware has been tampered with and the verification fails.

7. The IAP upgrade method based on multi-stage CRC check according to claim 1, characterized in that: It also includes the firmware upgrade phase, the specific steps are as follows: Identify the difference between the new firmware and the old firmware by using a binary difference algorithm, and generate a difference patch file; wherein the difference patch file contains the difference between the new firmware and the old firmware; The firmware in the internal FLASH is upgraded through the differential patch file.

8. The IAP upgrade method based on multi-stage CRC check according to claim 7, characterized in that: The firmware upgrade stage also includes the following steps: After the upgrade is completed, the integrity of the upgraded firmware is checked. If the check is successful, the entire upgrade process is completed; if the check fails, the upgrade is performed again.

9. The IAP upgrade method based on multi-stage CRC check according to claim 7, characterized in that: Upgrading the firmware in the internal FLASH by using the differential patch file specifically includes: Obtaining positioning information in the difference patch file; The difference part is written into the corresponding area of ​​the old firmware according to the positioning information.

10. The IAP upgrade method based on multi-stage CRC check according to claim 3, characterized in that: The device to be upgraded is STM32.

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