Using Persistent User Storage

This application note gives a description of the persistent user storage and how it can be used.

1. Overview

The NavQ+ software releases come as an image which is flashed over to the on-board EMMC or an SD card.

In either case the flashing process wipes out the storage and replaces it with the new contents.

The persistent user storage is intended to define a designated storage location which is not affected during the flashing process, thus its contents survives the software update.

The persistent user storage uses a dedicated partition on either EMMC or SD (depending on which storage devices is used for booting), and mounts it to /data directory.

2. Generic Usage

User may use /data directory to place whatever files they need to be preserved across software updates. Currently, the persistent data partition size is fixed at 512M.

3. Network Connection Sync Up

In addition to the generic usage, the NavQ+ BSP software uses this directory to sync up the network connections created by user. These can be WIFI, VPN, and other connection types. The sync up scripts create /data/NetworkManager directory to maintain copies of systems connection files created by the Network Manager daemon in /etc/NetworkManager directory. Theses files then used to restore the network manager connections on the first boot after a BSP software update.