7.6. Memory and Storage
7.6.1. Minimum Memory and Storage
- [C-0-1] MUST include a Download Manager that applications MAY use to download data files and they MUST be capable of downloading individual files of at least 100MB in size to the default “cache” location.
7.6.2. Application Shared Storage
- [C-0-1] MUST offer storage to be shared by applications, also often referred as “shared external storage”, “application shared storage” or by the Linux path “/sdcard” it is mounted on.
- [C-0-2] MUST be configured with shared storage mounted by default, in other words “out of the box”, regardless of whether the storage is implemented on an internal storage component or a removable storage medium (e.g. Secure Digital card slot).
- [C-0-3] MUST mount the application shared storage directly on the Linux path
sdcard or include a Linux symbolic link from
sdcard to the actual mount point.
- [C-0-4] MUST enforce the
android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage as documented in the SDK.
- [C-0-5] MUST enable scoped storage by default for all apps targeting API level 29 or above, except in the following situations:
- when the app was installed before the device upgraded to API level 29, regardless of the target API of the app.
- when the app has requested
android:requestLegacyExternalStorage="true" in their manifest.
- when the app is granted the
- [C-0-6] MUST enforce that apps with scoped storage enabled have no direct filesystem access to files outside of their application-specific directories, as returned by
Context API methods such as
- [C-0-7] MUST redact location metadata, such as GPS Exif tags, stored in media files when those files are accessed through
MediaStore, except when the calling app holds the
Device implementations MAY meet the above requirements using either of the following:
- User-accessible removable storage, such as a Secure Digital (SD) card slot.
- A portion of the internal (non-removable) storage as implemented in the Android Open Source Project (AOSP).
If device implementations use removable storage to satisfy the above requirements, they:
- [C-1-1] MUST implement a toast or pop-up user interface warning the user when there is no storage medium inserted in the slot.
- [C-1-2] MUST include a FAT-formatted storage medium (e.g. SD card) or show on the box and other material available at time of purchase that the storage medium has to be purchased separately.
If device implementations use a portion of the non-removable storage to satisfy the above requirements, they:
- SHOULD use the AOSP implementation of the internal application shared storage.
- MAY share the storage space with the application private data.
If device implementations include multiple shared storage paths (such as both an SD card slot and shared internal storage), they:
- [C-2-1] MUST allow only pre-installed and privileged Android applications with the
WRITE_MEDIA_STORAGE permission to write to the secondary external storage, except when writing to their package-specific directories or within the
URI returned by firing the
- [C-2-2] MUST require that the direct access associated with the
android.permission.WRITE_MEDIA_STORAGE permission is only given to user-visible apps when the
android.permission.WRITE_EXTERNAL_STORAGE permission is also granted.
- [SR] STRONGLY RECOMMENDED that pre-installed and privileged Android applications use public APIs such as
MediaStore to interact with storage devices, instead of relying on the direct access granted by
If device implementations have a USB port with USB peripheral mode support, they:
- [C-3-1] MUST provide a mechanism to access the data on the application shared storage from a host computer.
- SHOULD expose content from both storage paths transparently through Android’s media scanner service and
- MAY use USB mass storage, but SHOULD use Media Transfer Protocol to satisfy this requirement.
If device implementations have a USB port with USB peripheral mode and support Media Transfer Protocol, they:
- SHOULD be compatible with the reference Android MTP host, Android File Transfer.
- SHOULD report a USB device class of 0x00.
- SHOULD report a USB interface name of ‘MTP’.
7.6.3. Adoptable Storage
If the device is expected to be mobile in nature unlike Television, device implementations are:
- [SR] STRONGLY RECOMMENDED to implement the adoptable storage in a long-term stable location, since accidentally disconnecting them can cause data loss/corruption.
If the removable storage device port is in a long-term stable location, such as within the battery compartment or other protective cover, device implementations are: