FPseNG - RetroBIOS¶
Technical notes
PlayStation emulator for Android, closed source, sold on Google Play as package com.emulator.fpse64 and named FPse64 until the rename. The build read here is 1.13, versionCode 245, minSdk 23, targetSdk 33, activity com.emulator.fpse64.Main. Google signs the package through Play App Signing, CN=Android O=Google Inc. issued 2020-05-02, sha256 5df4c204abac4d2a10c4b8f497689e28c2bfb5dc44a56081ebb4a5e1c2f1d27f, and that signature block travels inside the copy read here: the repackager kept the original apk as assets/SignatureKiller/origin.apk, whose MANIFEST.MF carries the sha256 of all 1278 entries of the distributed build. 1274 match byte for byte, among them every native library and every resource; AndroidManifest.xml, classes.dex and resources.arsc differ, stamp-cert-sha256 is dropped and one class, bin/mt/signature/KillerApplication, is added. Native code and resources are therefore the distributed ones and the java below is the application's own, minus that injection. A second copy, apkvision 1.8, is signed with the Android test key and ships three of the eight libraries its own core links against; it is read only to confirm that the preference key, the two size tests and the checksum constant below are the application's and not the repackager's. ref: com.emulator.fpse64 1.13 assets/SignatureKiller/origin.apk META-INF/GOOGPLAY.RSA, META-INF/MANIFEST.MF
Two roots hold everything. The private files directory of the package is the one the core is given, and bios, plugin, cfg and skin are created under it right after the libraries load; the emulator resolves its own paths against it. The second is a directory named FPse64 at the root of shared storage, holding memcards, cheats, shaders, ogl, sbi, sstates, titles, icons, videos and filelist.txt. Paths below are relative to the first root unless they name the second. ref: Main.java:36420, Main.java:3004, Main.java:27329-27332, Main.java:27458-27459, Main.java:30411-30413
Exactly one BIOS image is ever loaded and its full path is a setting rather than a name the code looks for. The Load Bios browser keeps .bin files and lists only those of exactly 524288 bytes, the chosen path is written to the preference com.emulator.fpse64.biospath and pushed into the core as string slot 6, and the stored path is re-checked at every start: a file that no longer exists or is not exactly 524288 bytes clears the preference and the session runs on HLE. Slot 6 receives the empty string whenever the path is empty, the BIOS switch is off or the launching intent carried bios=0, which is the documented way to ask for HLE; the shortcuts the application pins carry that same extra. On the core side the value is opened as given, then retried below bios/ under the root, so a bare name resolves there; a hit is read as one block of 0x80000 bytes after "Loading '%s'...", and a miss reports "Can't load biosfile '%s', switching to HLE", sets the HLE bit and writes "CEX-3000/1001/1002 by K.S.", "System ROM Version 2.2 12/04/95 A" and the Sony copyright line into BIOS memory, so no image is needed on its own. The FAQ on the emulator's own site states that a file named scph1001.bin is recommended and is not distributed with the emulator. ref: Main.java:1169, Main.java:21925-21927, Main.java:25833-25835, Main.java:9943-9977, Main.java:30177-30192, Main.java:5392-5396, Main.java:36446-36451, Main.java:28751-28754, libfpse.so 0x70e20-0x70f20, fpsece.net/faq.html
Automatic detection recognises one dump and does it on content. Scanning storage, FPseNG keeps files whose lowercased name ends in .bin and whose length is exactly 524288, reads all 524288 bytes, sums them as signed bytes and accepts the file when the total is 85958, writing the path to the preference and turning the BIOS on. The same constant answers over NFS through isnfsbios. Recomputed over the collection, that sum resolves to a single image, the v2.2 12/04/95 A dump listed below, and to no other. The HLE path impersonates the same revision: its identification strings sit in .rodata beside "HLE enabled." and the library carries no 512 KB image of its own. ref: Main.java:24466-24487, Main.java:24491, Main.java:25670, libfpse.so .rodata 0x1b8d81-0x1b8dfb
Emulation is split across libraries the core links against. libfpse.so lists libopengl, libsoft1, libspuplugin, libneon, libsdl and libnfsplugin in DT_NEEDED, and Main names uncompress, spuplugin, soft1, nfsplugin and opengl before fpse; sdl and neon are named earlier from a static block that swallows UnsatisfiedLinkError, the rest are not guarded. All eight ship in the package for arm64-v8a and no other ABI. Eighteen constants naming nine plugins296 archives on fpse.net and fpsece.net survive in the class and nothing reads them, and the two archive extractors keep a branch counting eight .so members that no caller reaches. What getfile.php still answers, once per versionCode and keyed by ABI as type p64, is a blob handed to setnfspos and summed into a preference, not a library anything writes to disk. An OpenGL plugin picked by hand from the .so browser is copied over libopengl1.so under the root. libGLESv2, libjnigraphics, liblog, libstdc++, libdl, libm and libc are the Android runtime and are not files anyone supplies. ref: Main.java:25134-25137, Main.java:27300-27312, Main.java:9985, Main.java:1116-1133, Main.java:8496, Main.java:13854, Main.java:23615-23621, libfpse.so readelf -d
Resources unpack through helpers that differ in one respect. The guarded one writes only when the target is absent, so bios/kanji.rom, fpse.ini and the whole skin set survive being replaced by hand, and the same rule puts slot1.mcd and slot2.mcd under FPse64/memcards on shared storage. The unguarded one truncates, so gamelist.ini is rewritten from the package at every start and a copy put there does not last. The shipped shaders are copied out of assets into FPse64/shaders once storage access is granted. ref: Main.java:33974-33977, Main.java:34054-34057, Main.java:34750-34753, Main.java:27334, Main.java:27346-27347, Main.java:27463, Main.java:35829-35845
What the application fetches for itself comes from the developer's servers: cheat files from fpse.net/c/, per title OpenGL option files packed as fpse.net/o/ogl.zip, covers from fpse.net/i64/, titles from fpse.net/t/, game notes from fpse.net/games64/, overlay pad skins from fpse.net/s/ as padtemp.zip extracted into skin/, and vrback.zip extracted at the root of shared storage. Files named after a game identifier and ending in .sbi are downloaded into FPse64/sbi for the titles of one internal list; no library and no java path reads them back, and the string ".sbi" appears in none of the eight libraries. ref: Main.java:10505-10507, Main.java:16605, Main.java:16644, Main.java:11468, Main.java:11827, l0.java:82-89, Main.java:10846, Main.java:11014, Main.java:12555-12585, Main.java:15415-15430, Main.java:15489
16 files | 7 required, 9 optional | 10 in repo, 6 missing | 1 with HLE fallback Categories: 3 BIOS, 13 game data
scph1001.bin optional in repo HLE fallback
SCPH-1001, DTL-H1201, DTL-H3001 (v2.2 12-04-95 A)
- Path:
bios/scph1001.bin - System: sony-playstation
- Size: 512.0 KB
- SHA1:
10155d8d6e6e... - MD5:
924e392ed055... - Validation: size
- Source:
Main.java:24466-24487,Main.java:9945-9952,Main.java:30177-30192,Main.java:5392-5396,libfpse.so 0x70e20-0x70ed0 - Platforms: batocera, lakka, recalbox, retroarch, retrodeck, retropie, rocknix, romm
- Config key:
com.emulator.fpse64.biospath - The only image the code identifies, and it identifies it by a checksum of its own rather than by a hash it spells out: the 524288 bytes summed as signed bytes, accepted at 85958. The md5 and sha1 here are the dump that reproduces that sum. Selecting a BIOS by hand takes any .bin of exactly 524288 bytes, so the other images of the group fill the slot without being recognised by name or by sum.
kanji.rom optional in repo bundled
FONTX2 font the core draws Japanese text with
- Path:
bios/kanji.rom - Size: 233.0 KB
- SHA1:
915880f8bb04... - MD5:
040d9dcbad83... - Source:
Main.java:27334,Main.java:33974-33977,libfpse.so 0x71074-0x710b4,libfpse.so 0x95ce0-0x95ce8 - Platforms: misterfpga
- Header FONTX2X11. Unpacked into bios/ at first start and left alone afterwards, so a replacement stays. The core appends the name to the root and its bios/ component, opens the result read only and carries on when the file is absent.
libsoft1.so required in repo game_data bundled
software renderer plugin
- Source:
Main.java:27302,libfpse.so readelf -d - Named by System.loadLibrary("soft1") outside any catch and listed in DT_NEEDED by the core. Also holds the VR background loader.
libspuplugin.so required in repo game_data bundled
sound plugin
- Source:
Main.java:27301,libfpse.so readelf -d - Named by System.loadLibrary("spuplugin") outside any catch and listed in DT_NEEDED.
libopengl.so required in repo game_data bundled
OpenGL renderer plugin
- Aliases:
libopengl1.so - Source:
Main.java:27304,Main.java:9985,libfpse.so readelf -d - Named by System.loadLibrary("opengl") outside any catch and listed in DT_NEEDED. A plugin chosen from the .so browser is copied over libopengl1.so under the root.
libnfsplugin.so required in repo game_data bundled
NFS client plugin, for discs read from a network share
- Source:
Main.java:27303,Main.java:25670,libfpse.so readelf -d - Named by System.loadLibrary("nfsplugin") outside any catch and listed in DT_NEEDED. Backs the isnfsbios and copyfromnfs entry points.
libsdl.so required in repo game_data bundled
SDL audio backend
- Source:
Main.java:25134,libfpse.so readelf -d - Named by System.loadLibrary("sdl") from a static block that catches UnsatisfiedLinkError, and listed in DT_NEEDED, so the core will not link without it.
libneon.so required in repo game_data bundled
NEON colour conversion routines
- Source:
Main.java:25135,libfpse.so readelf -d - Named by System.loadLibrary("neon") from the same static block and listed in DT_NEEDED.
libuncompress.so required in repo game_data bundled
archive extractor for .zip, .rar, .7z, .ape and .ecm images
- Source:
Main.java:27300,Main.java:25408,libfpse.so readelf -d - Named by System.loadLibrary("uncompress") outside any catch, and the only one of the plugins the core does not list in DT_NEEDED.
<shader>.vsh optional missing game_data bundled
vertex shader read whole and handed to the OpenGL renderer
- Path:
FPse64/shaders/<shader>.vsh - Source:
Main.java:25962-25975,Main.java:35655-35669,Main.java:35829-35845 - The Shaders setting walks the directory and reads the selected pair, passing the bytes to setVSH. The packaged set is copied out of assets once storage access is granted, and a pair dropped in by hand joins the list.
<shader>.fsh optional missing game_data bundled
fragment shader read whole and handed to the OpenGL renderer
- Path:
FPse64/shaders/<shader>.fsh - Source:
Main.java:25983-25996,Main.java:35677-35691,Main.java:35829-35845 - Read from the same directory as the vertex shader of the same name and passed to setFSH.
vrback.raw optional in repo game_data
background image the software renderer draws behind the VR view
- Source:
libsoft1.so 0x5fda8-0x5fdb8,libsoft1.so 0x5fa3c-0x5fa50,Main.java:12555-12585 - Opened read only at the root of shared storage and read as 640 by 512 sixteen bit pixels. Not carried by the package: the application downloads fpse.net/vrback.zip, extracts it at that root and deletes the archive. The distributed file is 655364 bytes.
<game>.txt optional missing game_data
cheat codes for one title
- Path:
FPse64/cheats/<game>.txt - Source:
Main.java:21973-21975,Main.java:10319-10357,Main.java:26918,Main.java:28219-28226 - The path is pushed into the core as string slots 140, 141 and 143, keyed by the licence string of the running disc. A file chosen through a browser listing .txt is copied there, and the cheat search writes its results to the same name.
<game>.txt optional missing game_data
OpenGL option mask for one title
- Path:
FPse64/ogl/<game>.txt - Source:
Main.java:29309-29322,Main.java:18286-18294,Main.java:16605-16644 - Read as a single integer and applied through setOptionGL, keyed by the licence string. Distributed as fpse.net/o/ogl.zip, which the application extracts into that directory, and rewritten there when the options are changed by hand.
<skin>.ini optional missing game_data
external overlay pad skin
- Path:
skin/<skin>.ini - Source:
Main.java:21943-21947,Main.java:27355,Main.java:11014 - Selected through a browser listing .ini files. The default set unpacks from the package as skin/pad.ini with its button and stick artwork, and a pack downloaded from the developer arrives as padtemp.zip and is extracted into the same directory.
LibPS.exe optional missing
PlayStation library executable loaded after the BIOS resources
- System: sony-playstation
- Source:
libfpse.so 0x95de8-0x95e1c,libfpse.so .rodata 0x1ba534 - Loaded by bare name during "Loading files..." when the matching option bit is set, reporting "LibPS.exe found and loaded." on success and continuing untouched when the loader returns -1. Not carried by the package, and the core never chdirs, so it resolves against the working directory of the process.
Generated on 2026-08-23T16:12:06Z