This page will cover the basics of extracting WipEout 2048 asset packs, and turning your mods into .fstar files that players can use. Information on how to modify the game's files directly once you've extracted them is not provided here, but there are other pages dedicated to a handful of file formats the game uses which can be found in the Table of Contents on the right-hand side.
As with any and all video games, before you can create mods, it's usually a good idea to dump the original assets first so you have an idea of what artwork the game is looking for and how you can manipulate it. If you don't have a good grasp of a game's internal filesystem then it can be a shot in the dark trying to replace the original assets effectively.
Extracting the original PSARC files
To extract PSARC files, we use a tool from the Vita SDK called PSP2PSARC.
You can download psp2psarc.exe here, or if you already have Firestar installed and set up, you can find it in your ~/.firestar/ folder.
The following instructions are for psp2psarc, the official Sony-developed archiving tool. Open-source alternatives may work differently.
For Windows (Powershell):
./psp2psarc.exe extract data.psarc
For Unix family systems:
wine psp2psarc.exe extract data.psarc
Use the -y flag to overwrite existing files from data.psarc when extracting patches and DLC:
./psp2psarc.exe extract -y data2.psarc
wine psp2psarc.exe extract -y dlc1.psarc
The above commands will extract to the current working directory. All of the WipEout assets are stored in a "data" folder inside of data.psarc and not the archive root, so this should all automatically end up in a data/ folder for you.
Creating .FSTAR Files
For storing mods, Firestar uses the common ZIP format with the FSTAR file extension. The contents of the ZIP are dumped directly over top of the original assets at build time when the user selects "Deploy" and then psp2psarc is called to re-bundle the assets together.
Auto-Generate a Mod File
Firestar has a built-in tool to create FSTAR files. First, create a folder containing your data/ directory, and any other files Firestar needs such as your delete.txt. Then click "Tools" and then "Generate New Mod from Folder...", and select the folder your mod files are in.
Manually Using a ZIP Archiver
Place your modified files inside of a new ZIP folder, ensuring that their path precisely matches the path of the originals you are replacing, including placing them in an all-encompasing data/ folder and not the ZIP root. Like so:
(And please, don't copy the ENTIRE data folder with the original assets. You will bloat your modpacks up tremendously, and you would also be committing piracy.)
Next, open the Comments editor.
On Peazip, this can be found in Tools > Comment or with the keyboard shortcut Alt+M. On WinRAR, this can be done by clicking the Comment button at the top toolbar.
Now write in your mod's metadata in JSON format. For example:
If you need to know what your loaderversion is, you can find it in the console output when you start Firestar:
Ah, but what is that "delete.txt" file? That's the delete list, and as the name suggests, Firestar will use this file to delete the files in the final PSARC that conflict with your mod if it is being installed.
audio/music/01/music_stereo.fft
audio/music/02/music_stereo.fft
audio/music/03/music_stereo.fft
audio/music/04/music_stereo.fft
audio/music/05/music_stereo.fft
audio/music/06/music_stereo.fft
audio/music/07/music_stereo.fft
audio/music/08/music_stereo.fft
audio/music/09/music_stereo.fft
audio/music/10/music_stereo.fft
audio/music/11/music_stereo.fft
audio/music/FEDemoMusic/frontend_stereo.fft
audio/music/FEMusic/frontend_stereo.fft
Place this file in the root of your ZIP if there are any files that need to be disposed of in order for your mod to work.
Now, save your zip with the .fstar extension, and import it into Firestar. Ta-da!