Abdessamad Derraz
7a3d91585d
ES-DE starts standalone MAME with -rompath %GAMEDIR%\;%ROMPATH%/<system> in 78 live commands across 54 systems (resources/systems/linux/ es_systems.xml at retrodeck-main-20261103-162710, 15e1b236; two more are commented out). The command line outranks mame.ini, so RetroDECK's MAME reads its sets in the roms folder each command names and in no BIOS folder. The ES-DE rom folders parser now records, per folder, the folders a standalone command passes as its ROM search path and the machines it starts, or that the game is the machine (%BASENAME%). Rescraped at the pinned revisions: retrodeck, emudeck and emudeck-windows gain these records and nothing else. A command reads the sets its machines load: the machine's own set, the BIOS sets on its romof chain and the device sets with ROMs it instantiates, from games/arcade/mame.json (mame0289 -listxml). That index now also lists the game and device sets of each driver source file, so a %BASENAME% folder reads for its board: neogeo and stv by their BIOS root, cps1-3 and model2 by source file, daphne and laserdisc by the laserdisc player devices, gameandwatch and lcdgames by the handheld sources, any other (arcade, mame, consolearcade) for every machine. The published installer copy of the index leaves the sources out. Manifests: RetroDECK gains 1399 files, 378.2 MB, below roms/. Of the 219 sets named as read outside the BIOS folder, 58 reach 146 files (25.9 MB), 161 stay named, no command's machine reading them. 441 sets RetroDECK's list also declares at bios/ reach 1253 files (352.3 MB), 429 each in arcade and mame and 480 in consolearcade. No other platform changes.
Platform Configs
How platform YAML files work and where subdirectory requirements come from.
Files
_registry.yml-- platform metadata (name, release pack, display order)_shared.yml-- shared file groups with canonical destinations<platform>.yml-- per-platform BIOS declarations- Inheritance:
lakka.ymlinheritsretroarch,retropie.ymlinheritsretroarch
Shared groups (_shared.yml)
The subdirectory a BIOS goes into is determined by the libretro core, not
the platform. NP2kai expects np2kai/BIOS.ROM whether you're on RetroArch,
Batocera, or Recalbox. Only base_destination varies (system/ vs bios/).
Shared groups define files with correct destinations once. Platforms
reference them via includes: [group_name] in their system definitions.
load_platform_config() in common.py resolves includes at load time,
deduplicating by filename.
When to use shared groups: whenever 2+ platforms share files that a core expects in a specific subdirectory. The group carries the correct destination so platforms can't drift.
For RetroArch specifically, libretro_scraper.py injects includes:
references and applies subdirectory prefixes via CORE_SUBDIR_MAP during
generation. Manual edits to retroarch.yml will be overwritten on next scrape.
Data directories (_data_dirs.yml)
Some cores need entire directory trees, not just individual BIOS files.
Dolphin needs dolphin-emu/Sys/ (GameSettings, DSP firmware, fonts),
PPSSPP needs PPSSPP/ (font assets, shaders), blueMSX needs Databases/
and Machines/ (machine configs).
These are defined in _data_dirs.yml as a central registry with upstream
source URLs. The pack generator auto-refreshes from upstream before building
(use --offline to skip). Data directories live in data/ (not bios/)
and are NOT indexed in database.json.
Adding a data directory:
- Add entry to
_data_dirs.ymlwith source URL, extraction path, cache location - Reference via
data_directories: [{ref: key, destination: path}]in platform systems - For scraper-generated platforms, add to
SYSTEM_DATA_DIRSin the scraper - Run
python scripts/refresh_data_dirs.py --key <name>to populate the cache
Subdirectory reference
Each entry documents where the requirement comes from. Check these source files to verify or update the paths.
| Core | Subdirectory | Source |
|---|---|---|
| NP2kai | np2kai/ |
libretro-np2kai/sdl/libretro.c |
| PX68k | keropi/ |
px68k/libretro/libretro.c |
| QUASI88 | quasi88/ |
quasi88/src/libretro.c |
| Kronos | kronos/ |
libretro-kronos/libretro/libretro.c |
| ep128emu | ep128emu/rom/ |
ep128emu-core/src/libretro.cpp |
| Flycast | dc/ |
flycast/shell/libretro/libretro.cpp |
| FBNeo NeoCD | neocd/ |
fbneo/src/burn/drv/neogeo/neo_run.cpp |
| Fuse | fuse/ |
fuse-libretro/fuse/settings.c |
| hatari | hatari/tos/ |
hatari/src/tos.c |
Full libretro docs: https://docs.libretro.com/library/<core>/
Adding a platform
- Create
platforms/<name>.yml - Set
base_destination(systemorbios),verification_mode,hash_type - Use
includes: [group]for systems with subdirectory requirements - Use
inherits: retroarchto share RetroArch's file set - Add platform-specific overrides in
overrides.systems - Test:
python scripts/verify.py --platform <name>
Adding a shared group
- Add the group to
_shared.ymlwith a source ref comment - Include: filename, destination with subdirectory prefix, required flag, hashes
- Reference via
includes: [group_name]in platform system definitions - For scraper-generated platforms, add the mapping in the scraper's
SYSTEM_SHARED_GROUPSdict so it persists across regeneration
Verification modes
| Platform | Mode | Native logic | Upstream source |
|---|---|---|---|
| RetroArch | existence | path_is_valid() -- file exists |
core_info.c |
| Lakka | existence | inherits RetroArch | idem |
| RetroPie | existence | inherits RetroArch | idem |
| Batocera | md5 | md5sum() + checkInsideZip() |
batocera-systems |
| RetroBat | md5 | MD5 check via JSON config | batocera-systems.json |
| EmuDeck | md5 | MD5 whitelist per system | checkBIOS.sh |
| Recalbox | md5 | multi-hash comma-separated | es_bios.xml + Bios.cpp |
| RetroDECK | md5 | MD5 per file via component manifests | api_data_processing.sh |
| RomM | md5 | size + any hash (MD5/SHA1/CRC32) | firmware.py |
| ROCKNIX | md5 | md5sum() + checkInsideZip() with altmd5 |
rocknix-systems |
| MiSTer FPGA | md5 | MD5 of the file at its destination | process_db_index_worker.py |
| BizHawk | sha1 | SHA1 per firmware entry | FirmwareDatabase.cs |