OpenPS2BIOS is an open-source PS2 BIOS for emulators, and 38 game discs already reach their menus in PCSX2

Tamariba Devs released an MIT-licensed PS2 BIOS with no Sony code in it. Version 0.2 fixed Gran Turismo 4's start-up a day later; gameplay, saving and sound are not yet confirmed.

AI-drafted from 5 sources. This story was written with AI from the outside reporting listed under Sources, and checked by automated tools before it went up. The originals have the full detail.

PCSX2's own setup guide is blunt about the BIOS. The files are Sony's, it says, so they "must therefore be dumped from your own console", and "no open-source alternative exists". A group called Tamariba Devs is trying to change the second half of that. OpenPS2BIOS went public on GitHub on 16 October: a replacement PlayStation 2 BIOS for emulators, MIT licensed, with its own boot screen and the EE and IOP kernels needed to start PS2 software, and no Sony firmware inside.

Every game on its compatibility table reaches its main menu in PCSX2. The list has 38 entries, separate discs counted on their own, including God of War, Shadow of the Colossus, Final Fantasy X International, Kingdom Hearts II Final Mix+, Persona 4 and all three Xenosaga games. Version 0.2 followed the next day with a fix for Gran Turismo 4, whose network worker was jumping in before start-up had finished. The US release now gets as far as its memory-card prompt in PCSX2 2.9.94.

A menu is not a game

The developers are careful about what that list means. Reaching a title screen, the README says, "does not establish that gameplay, saving, sound or controller input works correctly", and none of those has been confirmed yet. There is no system menu, memory card browser or clock setting. PS1 discs, audio CDs and DVD video do not work, and encrypted KELF modules are not supported. A game that calls something not yet written simply stops, on purpose, so the gap shows up at once rather than as a crash later.

It is for emulators only. OpenPS2BIOS skips the hardware set-up an emulator does for itself, such as the memory controller, so it will not boot on a real PS2, and the project warns against flashing it to one.

The README also declines to call the work clean-room. The team used public hardware documentation, PS2SDK and PCSX2 source, and tests against a retail BIOS, and says it copied no implementation code, but there was no separate team turning findings into a specification. Contributors are asked to cite their sources and not to use leaked Sony SDKs or decompiled Sony firmware, and code with unclear origins will not be merged until that is settled.

Sources

More news from Gaming World