There are always changes in the software features and requirements of home wireless routers. Users always expect to use the latest software functions to allow routers to complete more tasks, thereby bringing they more and better functional experiences. However, the software version of the router has an iterative process. The software of the router will continue to add new functions and release new versions. If users want to obtain the latest router software version, one way is to obtain the latest router software version through the manufacturer's official website, and the other is to get it through the distributor. And then the user completes the upgrade through the router's WEB page.
CERES routers also support the above two methods to help customers obtain the latest software version, but not every router user is an IT professional and can independently complete the software upgrade of the router. At the same time, if faced with a large number of upgrade requirements, customers also cannot accept the use of a single upgrade method to complete the software update of batch equipment. As one of the best network solution providers, we have been working on the upgrade of the router. Based on the above router upgrade requirements, CERES has developed the FOTA automatic upgrade function to make router upgrades worry-free.
The development ideas of CERES FOTA online automatic upgrade function are as follows:
(1) Use a unified interface to call different functions through different input parameters to achieve different upgrade methods, such as TR069, WEBUI, and FOTA.
(2) Add header files to the files that need to be upgraded, and distinguish different upgrade files by adding specific keywords in the file header.
(3) Encrypt the files that need to be upgraded. After the files are downloaded to the device, use the corresponding secret key to decrypt the files through the software.
(4) Partition by marked location and enable partition switching after upgrade.
CERES has added the upgrade type, hardware version number, software version number, MD5 value and other information to the upgrade file header definition to distinguish and verify the upgrade file, so as to avoid the router from upgrading the wrong file during the automatic upgrade process and causing the router to be damaged. After using the FOTA online upgrade function, users no longer have to worry that their multiple routers in home will not enjoy the latest software features.
The main problem faced by this online upgrade method of routers is that the router loses power during the upgrade process. If the router is powered off when the router is performing ROM erasing, the router has not written the original upgrade file to the device at this time, and the original software image file is not complete, then the device will be abnormal when it is powered on again, which will only stay in the boot mode, and the business cannot be restored. Similar to the online upgrade of our mobile phone, the user will be prompted not to cut off the power or maintain sufficient power on the mobile phone screen. Faced with this huge online upgrade challenge, CERES has adopted two methods to deal with it. The first method is dual software mirroring backup, and the second method is software mirroring differential backup.
The first method is easier to be understood. When FOTA is automatically upgraded online, the upgrade software is written into the backup area of the router (for example, the router is currently running in the image1 area, then the backup area is the image2 area), even if the upgrade fails or the device powered off in the upgrade process, it will not affect the normal operation of the router. You only need to upgrade again until it succeeds.
The second method: When performing FOTA online upgrade for the router, first load the upgrade image to the RAM of the router. Then compare the difference between the upgrade image file and the image file running on the current router to form a differential image file, which is stored in the Overlay area with the user configuration file. After completing the above operations, perform the image file upgrade. If the device is powered off, the router can be powered on again, and the mirroring can be rolled back through the differential mirroring in the Overlay area and the user configuration file, so as to ensure that the service of the device is not interrupted due to the failure of the online upgrade.
CERES totally guarantees the worry-free upgrade of router equipment by adopting the above FOTA online automatic upgrade method and protection mechanism.
CERES's online automatic upgrade page is shown