Sometimes it is interesting to use a non-volatile RFS in order to maintain configuration and user data that need to be retained after rebooting. For example, a web server that updates a database with user information should keep this information in non-volatile storage to work fine. In this recipe, you will learn how to generate image files that include different partitions in only one file. This is handy to provide to the customer an easy way to upgrade a system. The image that will be generated will be an EXT3 filesystem that will reside in the SD card.
We will use the last Buildroot status as a basis for this example.