VPFS

VPFS (Vita PKG File System) is a virtual file system for the Sony PlayStation Vita that allows access to PKG archives (such as the kind you get from PSN) without having to go through a costly decryption and installation process.

In other words, VPFS is designed to grant PS Vita users complete access to PKG files as if they had been installed on one's system.

This is achieved by:

• First, creating a small .vpfs content database for each archive
• Second, running a kernel module that consumes the .vpfs data and, along with the original .pkg file can reconstruct the virtual data, such as file listing, decrypted data and so on, and present it as local file system content

License

GNU General Public License (GPL) version 3.

Status

ON HIATUS

Unfortunately, promotion does not rely on SceIo... calls, or even ksceVfsOpen() and friends, which means that this whole endeavour has become pointless, since our goal was to enable the running of .pkg files, just like .iso/.cso could be run on PSP, without having to extract anything...

There are just too many levels of file system access indirection on the Vita, and our time is too limited to try to figure how to override them all.

So while you can use this project to browse and read data from .pkg without having to exract them, in VitaShell, you cannot use it to promote or run apps because there are unknown file system calls which we don't know how to override (and we have now moved to working on other non PS Vita related stuff).

Compilation and testing

1. Download the Ridge Racer game installer pkg from here (777 MB).
2. Rename the file to UP0700-PCSE00001_00-RIDGERACERPSVITA.pkg.
3. Compile the vpfs PC application from the root directory.
4. On PC, run the command vpfs UP0700-PCSE00001_00-RIDGERACERPSVITA.pkg to create the PCSE00001.vpfs file. You can also add the zRIF if you want a work.bin to be embedded in the .vpfs.
5. Copy UP0700-PCSE00001_00-RIDGERACERPSVITA.pkg to ux0:pkg/ (you may need to create this directory) and PCSE00001.vpfs to ux0:app/.
6. Compile the module application in module/ (vpfs.skprx) and copy it to ux0:tai/.
7. Compile the test application in test/ (vpfs_test.vpk) and install it on your Vita.
8. Run the test application which will load the kernel module, run a series of tests, and then unload the kernel module.

Alternatively, you can choose to close the application when it asks you to press X to continue with the tests to keep the kernel module loaded. Then you can try to open VitaShell, which should let you navigate to ux0:app/PCSE00001/ and let your browse the content of the PKG, even as it has not been installed.

TODO

• Complete the overrides (async calls and so on).
• Validate that VPFS content can be promoted if work.bin is present.
• Validate that a promoted application can run as a VPFS.
• File/directory deletion.
• Create an SceShell module/plugin/app that detects .pkg and creates the relevant .vpfs.
• Double buffering for read + AES-CTR decription and other optimisation.
• Support other types of archives besides .pkg (e.g. .zip).

Credits

• mmozeiko for pkg2zip on which the vpfs PC application is based.
• yifanlu for taiHEN.
• TheFlow, CelesteBlue and dots-tb for their awesome work on varions applications that have been invaluable for the creation of the kernel plugin.
• Everyone who contributed to the Vita SDK.