Discoverable Disk Image (DDI) #
DDIs (Discoverable Disk Images) are self-described file system images that follow the DPS
Discoverable Partitions Specification), wrapped in a GPT
partition table, that may contain root (or
/usr/) filesystems, system extensions, system configurations,
portable services, containers and more, and are all protected by signed dm-verity all combined into one.
They are designed to be composable and stackable, and provide security by default.
Image Format #
The images use the GPT partition table verbatim, so it will not be redefined here. Each partition contains a standard Linux filesystem (e.g.: squashfs), so again this will not be redefined here. The ( DPS) defines the GUIDs to use and the format of the dm-verity signature partition’s JSON content.
Image Version #
If the DDI is versioned, the version format described in the
Version Format Specification must be used. The underscore character (
must be used to separate the version from the name of the image. For example:
foo_1.2.raw denotes a
DDI with version