Put RetroArch BIOS files in the right System folder on Android
Open Settings → Directory → System/BIOS and treat the displayed location as the starting point. Then read the selected core's official BIOS table: some cores expect the file directly in that directory and others require a named subfolder. Match the exact filename, extension, case, and documented hash. A successful content scan does not prove that firmware is present or correct.
Do this in order
- 01
Record the RetroArch package and version, selected core and version, content identity, and the System/BIOS path shown under Settings → Directory.
- 02
Open that core's first-party documentation and list every required and optional firmware filename, subfolder, region, and published hash.
- 03
Obtain firmware only from your own hardware or another source you are legally entitled to use; do not use a BIOS pack.
- 04
Copy only the required file into the documented location, preserving exact name, extension, case, and any required subfolder.
- 05
Calculate the file hash outside RetroArch and compare it with the core's published value before changing core options or content names.
- 06
Restart RetroArch, inspect the core's firmware status if exposed, and test one authorized known-good item while preserving the original diagnostic receipt.
Decision and diagnostic table
| Observation | Likely boundary | Next check |
|---|---|---|
| File is in System; core says missing | Wrong subfolder, name, case, or hash | Compare the core BIOS table field by field |
| System path changed after reinstall | Package or storage configuration | Use the path currently displayed in Directory |
| BIOS is optional | Core may use HLE or reduced compatibility | Read the exact core note before deciding |
| Scan finds game; launch still fails | Firmware or core compatibility | Check firmware independently from the playlist |
The active directory is evidence; a remembered path is not
RetroArch distributions can expose different storage locations on Android. The Directory screen identifies the configured System/BIOS location, while the core page decides whether a subfolder is required. Copying the same file into several guessed folders hides the actual configuration.
Location, name, and hash are separate gates
A correctly named file can still be the wrong revision or a damaged copy. Conversely, a valid hash in the wrong subfolder is still invisible to the core. Preserve all three checks so a later package or core update can be diagnosed without downloading replacement files.
Firmware status is not a content license
Libretro documents requirements but does not distribute copyrighted system firmware. Keep the hardware or rights receipt separate from the technical hash and never attach firmware to a support report.
BIOS and other firmware can be copyrighted even when a core requires them. Use only a dump or file you are legally entitled to possess, and never download, bundle, mirror, or share a BIOS pack through ArcadeShelf.