By setting up permission properly for each data handled by the application, you can share data and/or allow other application only to read data.
There is no plan to provide a mechanism to share the ROM data of an application; permission features are put to use for the following data.
WFS is used to handle data mentioned above. The WFS permission specification should be described below.
There are 3 types of categories: "Owner", "Group", and "Other" to switch the WFS permission. Two types of IDs: OwnerID and GroupID are used to identify the categories. The length is 64-bit and 20-bit (*1) respectively; only one of each can be specified per entry (file, directory).
In case of save data, the TitleID of the application that has created the root directory, directory, and file is set as OwnerID and GroupID as GroupID automatically. In case of add-on content, GroupID is set as GroupID automatically as well but OwnerID is set to zero.
IDs can be set up by the Wii U Application Configuration Tool. However, you cannot set up/change OwnerID and GroupID for an entry within the application or obtain a value to compare with its own ID.
*1: GroupID is kept 32-bit-long within the system; 20 bits of which is what the application needs to care about. It can be set up by the Wii U Application Configuration Tool.
There are 3 permission types: Read (
r), Write (
w), and Execute (
x). The default for each data and category
is as shown below.
The application receives a result according to permission via FS APIs. For example, an attempt
to open a read-only file as a writable one should result in
FAT (SD card access) and PCFS support only simple settings for all entries as follows:
Currently, the application can change permission using the following:
2013/06/28 Updated description about add-on content. Replaced the term "added contents" to "add-on content".
2013/05/08 Automated cleanup pass.
2012/11/20 Replaced "FAT32" to "FAT".
2012/09/12 Modified description in Permission Type section.
2012/09/11 Initial version.