M64Plus FZ - RetroBIOS¶
Technical notes
Android fork of Mupen64Plus AE, whose paulscode.android.mupen64plusae namespace it keeps, published under three package ids built from one code line: org.mupen64plusae.v3.fzurita, the paid .pro and the Amazon .amazon. Those flags gate advertising and Google Drive backup and nothing else (AppData.java:334-337, DataPrefsActivity.java:173-182, GamePrefsActivity.java:288-296), so the three packages want the same files. The repository default branch is a 2017 snapshot of the parent project; the application is built from fz-master, which carries mupen64plus-core, the hle, cxd4 and parallel RSP plugins, the GLideN64, glide64mk2, gln64, rice, angrylion-plus and parallel video plugins, its own audio, touchscreen and raphnet input plugins, and a miniupnp bridge for netplay (settings.gradle:1). ES-DE launches it for both n64 and n64dd with an ACTION_VIEW intent carrying a storage access uri, which the splash screen forwards to the gallery as a rom path (AndroidManifest.xml:83-96, ActivityHelper.java:191-198).
Cartridge boot needs no boot ROM. The PIF boot sequence is simulated (mupen64plus-core device/pif/bootrom_hle.c:48, entered from device/r4300/interrupt.c:445,496 and main/main.c:1875) and the CIC-NUS-6105 challenge is answered by an algorithm rather than a stored table (device/pif/n64_cic_nus_6105.c:93). Nothing fills the PIF ROM window from a file.
Which 64DD IPL is used is not decided by the code. Two settings hold a path and both end up as the same working file dd_rom.n64: the global one, titled 64DD IPL (J), read when the launched file is itself a disk, and a per game one, titled 64DD IPL, read when a cartridge is launched with a disk attached (CoreService.java:599-612, CoreInterface.java:142,229,455-484). The core offers a callback that would name the image per disk region and the front end leaves it null (CoreInterface.java:221, main/main.c:1082-1086), so whichever image sits in the slot is the one loaded. A disk is recognised only when its system data header matches and carries one of three region words, 0xe848d316 for Japan, 0x2263ee56 for the United States and 0x00000000 for development (RomHeader.java:180-212); the word sets a country code used for the ROM database and cheat lookup, never for picking the IPL. Launching a bare disk with the global slot empty stops before the core starts (CoreService.java:621-623), and since disk only games still need a cartridge image the application feeds the m64p_test_rom.v64 asset in its place (CoreService.java:620,625-630). Disk content inside a .zip or .7z is unpacked to the working directory first (CoreInterface.java:486-518).
Transfer Pak carts come from four per player path settings copied into the working directory as playerN_gb_rom.gb and playerN_gb_ram.gb (CoreService.java:558-568, CoreInterface.java:173-188,219-220,416-453). The core rejects a cart under 32 KiB and an unknown type byte at 0x147 (device/gb/gb_cart.c:994-1008) and fixes no name, size or hash, so neither the cart nor its save carries an entry here.
Seven data files ship inside the package and are unpacked on first start into the private files directory, which is also what the core is told is SharedDataPath (ExtractAssetsOrCleanupTask.java:63-73, SplashActivity.java:402, AppData.java:411-423, NativeConfigFiles.java:112). mupen64plus.ini is the ROM database, read by the core (main/rom.c:473-490 from api/frontend.c:106) and by the gallery (SplashActivity.java:447, ScanRomsFragment.java:195, GamePrefsActivity.java:244). mupencheat.default is copied over Profiles/customCheats.txt into mupencheat.txt and parsed in Java (SplashActivity.java:443, CheatUtils.java:88-93, GamePrefsActivity.java:618); the core's own cheat.c opens no file. font.ttf is reached by GLideN64 only after /system/fonts/DroidSans.ttf fails, which it does on current Android (TextDrawer.cpp:201-233,235-241, NativeConfigFiles.java:292); the core's OSD, the other upstream reader of that name, is absent from the Android source list (mupen64plus-core.mk:24-101). RiceVideoLinux.ini holds rice's per ROM settings (rice Config.cpp:38,933-951), Glide64mk2.ini glide64mk2's (glide64mk2 Main.cpp:1581-1590), and gln64.conf with gln64rom.conf gln64's global and per ROM settings (gln64 Config.cpp:245-252,296-300).
Two more assets are read straight out of the package and never unpacked: m64p_test_rom.v64, and GLideN64.custom.ini, whose per ROM overrides the front end reads itself and writes into mupen64plus.cfg (AppData.java:416-417, ConfigFile.java:224-230, NativeConfigFiles.java:224). GLideN64 also asks the core for GLideN64.custom.ini in SharedDataPath, where it was never placed, so that native lookup finds nothing (Config_mupenplus.cpp:325-341). The touchscreen skins, the shader files and the controller, touchscreen and emulation profile templates are used from the package the same way (AppData.java:412,421-423).
Optional content with no canonical artifact: hi-res texture packs under
CoreConfig/UserData/mupen64plus/hires_texture, imported from a user archive
(GlobalPrefs.java:472, NativeConfigFiles.java:268, ExtractTexturesFragment.java),
the
Written rather than obtained: mupen64plus.cfg and the plugin sections in it, the mempak, eeprom, flashram and sram saves given default content when absent (main/main.c:1015-1078,1619-1622) and the 64DD disk save in whichever of the two formats SaveDiskFormat selects (main/main.c:365,1176-1235), savestates, screenshots, the texture dump and cache directories, the GLideN64 shader cache and romInfoCache.cfg (GlobalPrefs.java:466-484, NativeConfigFiles.java:109-112,276,289).
One file in the tree this build never reads: cxd4's rsp_conf.bin. Its reader is the zilmar variant of update_conf behind #if !defined(M64P_PLUGIN_API); the build defines that macro (mupen64plus-rsp-cxd4.mk:8), so the variant compiled takes its settings from the core config API and ignores the filename it is handed (mupen64plus-rsp-cxd4 module.c:83-93,239,637-659).
3 files | 3 required, 0 optional | 3 in repo, 0 missing
64DD_IPL_JP.n64 required in repo
64DD IPL ROM (Japanese retail)
- System: nintendo-64dd
- Aliases:
64DD_IPL_v12_JPN.bin,64DD_IPL.bin - Validation: signature
- Source:
app/src/main/java/paulscode/android/mupen64plusae/jni/CoreService.java:599-612,app/src/main/java/paulscode/android/mupen64plusae/jni/CoreService.java:621-623,app/src/main/java/paulscode/android/mupen64plusae/jni/CoreInterface.java:455-484,app/src/main/java/paulscode/android/mupen64plusae/persistent/GlobalPrefs.java:417,app/src/main/java/paulscode/android/mupen64plusae/persistent/GlobalPrefs.java:715,mupen64plus-core/upstream/src/main/main.c:1080-1145 - Platforms: emudeck
- The image every commercially released disk needs, and the one the global setting is named for. No name is fixed by the code: the path comes from a document picker with no extension filter and the file is copied to dd_rom.n64 before the core sees it. The core reads it whole, then byteswaps after identifying the first word as one of 0x80270740 (z64), 0x40072780 (n64) or 0x27804007 (v64); any other value logs an invalid IPL and disables 64DD. Size is not checked and no hash is computed.
64DD_IPL_US.n64 required in repo
64DD IPL ROM (American retail)
- System: nintendo-64dd
- Aliases:
64DD_IPL_USA.bin,IPL_USA.n64 - Validation: signature
- Source:
app/src/main/java/paulscode/android/mupen64plusae/util/RomHeader.java:180-212,app/src/main/java/paulscode/android/mupen64plusae/jni/CoreInterface.java:221,app/src/main/java/paulscode/android/mupen64plusae/jni/CoreInterface.java:455-484,mupen64plus-core/upstream/src/main/main.c:1080-1145 - Platforms: emudeck
- Needed for a disk whose system data carries the US region word 0x2263ee56, which the header reader accepts alongside the Japanese and development words. The front end holds one IPL path at a time and never branches on that region, so this image is loaded by putting it in the same setting. Same load path, format check and absence of size or hash validation as the Japanese image.
64DD_IPL_DEV.n64 required in repo
64DD IPL ROM (development)
- System: nintendo-64dd
- Aliases:
64DD_IPL_DEV.bin,IPL_DEV.n64 - Validation: signature
- Source:
app/src/main/java/paulscode/android/mupen64plusae/util/RomHeader.java:180-212,app/src/main/java/paulscode/android/mupen64plusae/jni/CoreInterface.java:221,app/src/main/java/paulscode/android/mupen64plusae/jni/CoreInterface.java:455-484,mupen64plus-core/upstream/src/main/main.c:1080-1145 - Platforms: emudeck
- Needed for a disk whose system data carries the development region word 0x00000000, the third value the header reader accepts before giving up on a file as a disk. Shares the single IPL setting with the other two images. Same load path, format check and absence of size or hash validation.
Generated on 2026-08-23T16:12:06Z