Folder Structure

RomM expects your library to be organised in one of two layouts. It tries Structure A first, and falls back to Structure B if A isn't found. This auto-detection is per-library (not per-platform), so if you don't pick one up front, just arrange files the way you prefer and it'll figure it out.

The two layouts

Both layouts separate ROMs from BIOS files, and they differ on whether the split lives at the top of the tree or inside each platform.

Structure A (recommended): one top-level roms/, one top-level bios/, platforms nested inside each

/roms/{platform}/
/bios/{platform}/

Structure B (fallback): one folder per platform at the top, roms/ and bios/ inside each

/{platform}/roms/
/{platform}/bios/

As the BIOS/firmware tree is optional, only platforms that require firmware for emulation need it.

Mount point

The path you mount into the container as /romm/library depends on which structure you pick:

Structure A: mount the parent of the roms/ folder.
Structure B: mount the parent of the platform folders.

See the reference Docker Compose for where /romm/library lives.

Platform folder names

The platform folder name has to match a known slug from the full list in Supported Platforms. If your existing folder names don't match (say, super_nintendo/ instead of snes/), override the mapping via system.platforms in config.yml.

Multi-file games

Some games come as folders instead of single files, which could include multiple disc, DLCs, manuals, or patches. These sub-folder names are recognised and surfaced as tags in the UI: dlc, hack, manual, mod, patch, update, demo, translation, prototype.

Visual reference

Structure A (recommended) Structure B (fallback)

library/roms/{platform}/{game} library/{platform}/roms/{game}

        library/
        ├─ roms/
        │  ├─ gbc/
        │  │  ├─ game_1.gbc
        │  │  └─ game_2.gbc
        │  │
        │  ├─ gba/
        │  │  ├─ game_3.gba
        │  │  └─ game_4/
        │  │     ├─ game_4.gba
        │  │     ├─ dlc
        │  │     │  ├─ game_4_dlc_1.7z
        │  │     │  └─ game_4_dlc_2.7z
        │  │     ├─ hack
        │  │     │  └─ game_4_hardmode.rar
        │  │     ├─ manual
        │  │     │  └─ game_4_manual.pdf
        │  │     ├─ mod
        │  │     │  └─ game_4_crazy_mode.zip
        │  │     ├─ patch
        │  │     │  └─ game_4_patch_v1.1.zip
        │  │     ├─ update
        │  │     ├─ demo
        │  │     ├─ translation
        │  │     └─ prototype
        │  │
        │  └─ ps/
        │     ├─ game_5/
        │     │   ├─ game_5_cd_1.iso
        │     │   └─ game_5_cd_2.iso
        │     │
        │     └─ game_6.iso
        │
        └─ bios/
           ├─ gba/
           │  └─ gba_bios.bin
           │
           └─ ps/
              ├─ scph1001.bin
              ├─ scph5501.bin
              └─ scph5502.bin

        library/
        ├─ gbc/
        │  └─ roms/
        │     ├─ game_1.gbc
        │     └─ game_2.gbc
        │
        ├─ gba/
        │  ├─ roms/
        │  │  ├─ game_3.gba
        │  │  └─ game_4/
        │  │     ├─ game_4.gba
        │  │     ├─ dlc
        │  │     ├─ hack
        │  │     ├─ manual
        │  │     ├─ mod
        │  │     ├─ patch
        │  │     ├─ update
        │  │     ├─ demo
        │  │     ├─ translation
        │  │     └─ prototype
        │  │
        │  └─ bios/
        │     └─ gba_bios.bin
        │
        └─ ps/
           ├─ roms/
           │  ├─ game_5/
           │  │  ├─ game_5_cd_1.iso
           │  │  └─ game_5_cd_2.iso
           │  │
           │  └─ game_6.iso
           │
           └─ bios/
              ├─ scph1001.bin
              ├─ scph5501.bin
              └─ scph5502.bin

Starting from scratch?

If you upload files through the web UI without any existing structure, it'll create Structure A on your behalf.

Naming convention

Filenames are parsed for region, language, revision, and arbitrary tags, with both [] and () delimiters supported:

Region/language: both ISO-like codes and full names. Add a custom region or language by prefixing with reg/reg- (e.g. reg MyOwnLang or reg-MyOwnLang).
Revision: prefix with rev/rev- (e.g. rev v1, rev-1)
Arbitrary tags: anything else in brackets is imported verbatim (e.g. tetris [1.0001](HACK)[!].gba)

Inline tags like (igdb-1234) in filenames can be used to force a match to a specific provider entry, covered in Metadata Providers → Filename tags.

Supported languages

Code	Language
Ar	Arabic
Da	Danish
De	German
El	Greek
En	English
Es	Spanish
Fi	Finnish
Fr	French
It	Italian
Ja	Japanese
Ko	Korean
Nl	Dutch
No	Norwegian
Pl	Polish
Pt	Portuguese
Ru	Russian
Sr	Serbian
Sv	Swedish
Zh	Chinese
nolang	No Language

Supported regions

Code	Region
A	Australia
AS	Asia
B	Brazil
C	Canada
CH	China
E	Europe
F	France
FN	Finland
G	Germany
GR	Greece
H	Holland
HK	Hong Kong
I	Italy
J	Japan
K	Korea
NL	Netherlands
NO	Norway
PD	Public Domain
R	Russia
S	Spain
SW	Sweden
T	Taiwan
U	USA
UK	England
UNK	Unknown
UNL	Unlicensed
W	World