LRPS2 - RetroBIOS

Type	libretro
Classification	Community forks
Source	https://github.com/libretro/ps2
Upstream	https://github.com/PCSX2/pcsx2
Version	Git
Profiled	2026-03-25
Cores	lrps2, pcsx2
Systems	sony-playstation-2
BIOS directory	pcsx2/bios/
Resources directory	pcsx2/resources/

Technical notes

Hard fork of PCSX2 (pre-Qt, 1.7-dev era) ported to libretro. x86_64 only. BIOS detection is filename-agnostic: scans pcsx2/bios/ for any file between 4-8 MB with a valid romdir structure (RESET + ROMVER entries). No hash validation. Companion files (.rom1, .rom2, .nvm, .mec) derive paths from the selected BIOS. DEV9 (network/HDD) and USB are stubbed in the libretro port. Widescreen patches are largely compiled into the core (libretro/patches.cpp). .info firmware_count=2 counts the bios folder and GameIndex.yaml. .info description mentions EROM.BIN but no EROM loading path exists in the code.

8 files | 1 required, 7 optional | 8 in repo, 0 missing | 2 with HLE fallback

<bios>.bin required in repo
PS2 BIOS binary

• Path: pcsx2/bios/
• Size: min 4.0 MB, max 8.0 MB
• Validation: size
• Source: pcsx2/ps2/BiosTools.cpp:231-254, pcsx2/ps2/BiosTools.cpp:267-322
• Scans pcsx2/bios/ for any file between 4 MB and 8 MB. Validates via romdir structure parsing (RESET + ROMVER entries). User selects BIOS via core option pcsx2_bios. Falls back to first valid BIOS found if configured BIOS is missing.

<bios>.rom1 optional in repo
DVD player ROM

• Path: pcsx2/bios/
• Size: max 4.0 MB
• Source: pcsx2/ps2/BiosTools.cpp:190-211, pcsx2/ps2/BiosTools.cpp:314
• DVD player ROM. Tries .rom1 (appended) then .rom1 (extension replaced). Silently skipped if not found.

<bios>.rom2 optional in repo
Chinese ROM extension

• Path: pcsx2/bios/
• Size: max 512.0 KB
• Source: pcsx2/ps2/BiosTools.cpp:190-211, pcsx2/ps2/BiosTools.cpp:315
• Chinese region ROM extension. Same naming convention as rom1. Only present on Chinese region consoles.

<bios>.nvm optional in repo HLE fallback
NVRAM / EEPROM data

• Path: pcsx2/bios/
• Size: 1.0 KB
• Source: pcsx2/CDVD/CDVD.cpp:224-267
• Console EEPROM data (language, timezone, region, iLink ID, OSD settings). Path derived from BIOS path with extension replaced to .nvm. Auto-created with region-appropriate defaults if missing or invalid.

<bios>.mec optional in repo HLE fallback
Mechacon version

• Path: pcsx2/bios/
• Size: 4 B
• Source: pcsx2/CDVD/CDVD.cpp:255-266
• Mechacon (disc drive controller) version as u32. Auto-created with default 0x00020603 if missing.

GameIndex.yaml optional in repo
game compatibility database

• Path: pcsx2/resources/GameIndex.yaml
• Source: pcsx2/GameDatabase.cpp:48, pcsx2/GameDatabase.cpp:981
• Platforms: lakka, retroarch, retropie
• YAML database of per-game patches, settings overrides, and compatibility fixes. OSD warning shown if missing. Some games may not boot or have issues without it.

cheats_ws.zip optional in repo
widescreen patches archive

• Path: pcsx2/resources/cheats_ws.zip
• Source: pcsx2/VMManager.cpp:375-388
• ZIP archive of per-game widescreen (16:9) patches in pnach format. Only loaded when widescreen patches are enabled via core options. Fallback if no patches found in pcsx2/cheats_ws/ folder.

cheats_ni.zip optional in repo
no-interlacing patches archive

• Path: pcsx2/resources/cheats_ni.zip
• Source: pcsx2/VMManager.cpp:410-423
• ZIP archive of per-game no-interlacing patches in pnach format. Only loaded when no-interlacing patches are enabled via core options. Fallback if no patches found in pcsx2/cheats_ni/ folder.

Generated on 2026-09-14T09:03:10Z