shadPS4 Firmware Modules Explained: sys_modules, LLE vs HLE, Game Folders, Updates and DLC

The "firmware modules" shadPS4 talks about are individual PS4 system module files (.sprx) that go in its sys_modules folder, such as libSceNgs2.sprx (audio) and libSceFont.sprx (fonts). They are not the whole PS4 firmware. shadPS4 reimplements most system functions itself (HLE) and loads modules from sys_modules directly (LLE) to cover parts its own versions do not handle fully yet. The game itself is an extracted folder containing eboot.bin and sce_sys/param.sfo; since v0.8.0 shadPS4 no longer installs PKGs. Updates and DLC each have a fixed place, covered below.

Everything here was checked against shadPS4 v0.21.0 (2026-10-30).

What shadPS4 uses

Where the user folder lives: if there is a user folder next to the shadPS4 program, it is used (portable mode). Otherwise it is %APPDATA%\shadPS4 on Windows, ~/Library/Application Support/shadPS4 on macOS and ~/.local/share/shadPS4 on Linux. Since v0.16.0 the config file is config.json (it used to be config.toml; shadPS4 offers to migrate the old one on startup).

HLE vs LLE: how an emulator handles PS4 system libraries

PS4 games constantly call system libraries for graphics, audio, controllers, video decoding, font rendering and more. An emulator has to provide those libraries to the game. There are two ways, defined by the shadPS4 wiki as:

shadPS4 is HLE-first. The kernel (libkernel), GPU driver (GnmDriver), video output (VideoOut), controller (Pad) and about 80 other system libraries are written by the emulator team. For some libraries where HLE is still incomplete (mostly audio decoding, video playback, fonts, and JSON/XML parsing), shadPS4 lets you load the real module through LLE.

The loading rule is simple: if the module is in sys_modules, it gets loaded. If not, shadPS4 falls back to HLE where one exists (the log says "switching to HLE"). If there is no HLE either, the call does nothing (the log says "No HLE available"), and the game may lose audio or subtitles, crash, or hang on a screen.

Modules placed in a sys_modules/<game ID>/ subfolder only apply to that game, which helps with per-game issues. The sys_modules location can also be changed in the settings.

Which modules sys_modules supports

The 34 modules listed in the shadPS4 README (2026-11-01), grouped roughly by name:

All files end in .sprx. The names tell you what each one handles: intro videos go through AvPlayer, sound effects and music through Ngs2 and the Audiodec family, text through the Font and FreeType families. So the symptoms of a missing module usually show up there too: no audio, black video, or missing text.

Why the full PS4 firmware is not needed

The PS4 system update is a single PS4UPDAT.PUP file containing the whole operating system. shadPS4's approach is "reimplement most things, fill gaps with individual modules," so it never loads the full system and only uses the few dozen modules above plus fonts.

Some PS4 emulators take the opposite route. Obliteration aims to run real PS4 system software, and Emulation General Wiki notes that it therefore needs PS4 firmware files. As of 2026-11-01 it cannot run any games.

Game formats: PKG, extracted folders, eboot.bin

Early shadPS4 could install some PKGs and shipped code to handle them. A March 2025 commit removed all of it, and the v0.8.0 release notes say "Removed fpkg support." Today shadPS4 does not handle encrypted install packages at all; it reads a plain folder.

CUSA IDs: a PS4 game's Title ID is four letters plus five digits. Bloodborne's European Game of the Year Edition, for example, is CUSA03173. PS4 does not encode the region in the prefix, so each regional release has its own ID. Built-in system apps use the NPXS prefix. shadPS4 game folders are usually named after this ID, and update folders, shader caches and per-game module folders are matched by it.

Where updates and DLC go

Updates sit at the same level as the game folder, named after the game folder plus -UPDATE (-patch also works). shadPS4 layers it on top of the base game at launch, so you do not merge files:

games/
├── CUSA00900/           ← base game (eboot.bin, sce_sys/…)
├── CUSA00900-UPDATE/    ← update
└── CUSA00900-mods/      ← optional: mod files

The same rule supports a -mods folder for mods, and there is a setting to ignore updates temporarily. Many compatibility reports note the game version they tested (Bloodborne 1.09, for example), and behavior can differ between versions.

DLC goes in a subfolder named after the game inside the add-on content directory. The default is user/addcont/<game ID>/, and the location can be changed in the launcher (QtLauncher) settings. The v0.21.0 release improved DLC (addcont) loading specifically. License-only DLC with no actual files (some unlock-type DLC) goes in user/licenses.

Multiple game folders: the launcher's "Paths" settings page lets you add several game directories and set separate directories for sys_modules, fonts and DLC.

Trophies

shadPS4 supports PS4 trophies. Showing them requires filling in the trophy key in user/keys.json. Without it, games still run normally.

Do PS5 emulators need any of this?

• KytyPS5's README says external low-level emulation modules are "neither required nor planned."
• SharpEmu's README says the project contains no copyrighted system firmware, game data or proprietary PlayStation assets.
• PS5 games also use eboot.bin as the main executable. In July 2026, SharpEmu's early project notes described loading real games' eboot.bin and loading system modules (PRX and sys_module). Current status is in PS5 emulator status.

Related guides

• Install and first setup: shadPS4 Windows setup guide
• Is your PC enough: PS4 emulator system requirements
• Which emulator: the best PS4 emulator in 2026
• Why PS4 can be emulated this way: PS4 vs PS5 emulation explained
• Legal questions: are PS emulators legal