This project is a demo of a complete update schema in the Raspberry Pi. [SWUpdate] (http://sbabic.github.io/swupdate) is used to update images and u-boot as a bootloader. Several shell scripts are used to verify the update.
Buildroot submodule is used to build the Rpi images and [Swu-generator] (https://github.com/rboussel/swu-generator) is used to create the .swu archive.
- mountpoint/data folder contains configuration and log files. This is the Data partition.
- overlay folder contains all scripts necessary to update the system. The init update verification script is in usr/sbin folder and the other in opt folder.
- rpi-scripts folder contains u-boot script
- swupdate folder contains an exemple of sw-description and a script to create the .swu archive. They are not used in the demo.
In this demo, the target has six partitions
- mmcblk0p1 - U-boot
- mmcblk0p2 - Kernel + Rootfs-1
- mmcblk0p3 - Kernel + Rootfs-2
- mmcblk0p5 - Application-1
- mmcblk0p6 - Application-2
- mmcblk0p7 - Data
mmcblk0p3 and mmcblk0p6 are rootfs and application copies. With the dual-copy strategy, SWUpdate update the inactive partition while the active partition is running. When the system reboots, u-boot boots the updated partition. If the new partitions are corrupted, u-boot or init script changed current rootfs and application partitions.
To verify update and partition state, three variables are used :
- test_validy : Enable to validate rootfs update. This is an u-boot variable
- UPDATE_STATE : Give the update state and enable to get back the update in case of power off
- APP_STATE : Enable to know if the previous application update fails or not
In this demo, the system get update archives from FTP server with the script get_archive_name.sh. This script verifies if there is a new archive and launch update. After the system reboot, the script verify_update checks if there was an update and launches application and rootfs verification.