OpenPS2BIOS 0.2: a free PS2 BIOS for PCSX2, with no Sony code

OpenPS2BIOS replaces the PS2 BIOS in emulators such as PCSX2, without any Sony code. Version 0.2 boots Gran Turismo 4; 38 games reach their menu.


A PS2 BIOS written from scratch

To work, PCSX2 requires the PlayStation 2 BIOS, dumped from your own console. OpenPS2BIOS, released by Tamariba Devs, offers another route: a replacement BIOS written from scratch, under the MIT license, which contains no Sony firmware. It includes an original boot screen and the EE and IOP kernels needed to run PS2 games. It is developed for emulators and tested in PCSX2.


Two releases in two days

• 0.1 (16 October 2026): the first release, a 4 MB ROM image to select as the BIOS in the emulator.
• 0.2 (17 October): fixes booting of Gran Turismo 4, which now reaches the memory card screen in PCSX2. The game itself has not been checked.

The compatibility list includes 38 games and discs that reach their main menu, among them God of War, GTA San Andreas, Final Fantasy X, Kingdom Hearts II Final Mix+, Metal Gear Solid 3, Shadow of the Colossus, Persona 4 and Ratchet & Clank. The project warns: reaching the menu does not prove that the game, sound, controller or saves work.


The limitations

• The boot screen only launches PS2 discs: no system menu, no memory card management, and no clock or language settings.
• PS1 discs, audio CDs and DVD videos are not supported, nor are encrypted modules (KELF).
• A game stops dead if it calls a function that has not been written yet.

The authors insist: do not flash this BIOS onto a real PS2, as it would not boot. They also point out that their method is not "clean room" in the strict sense: they rely on public documentation, the PS2SDK, PCSX2's code and tests compared against an original BIOS, without copying its code. For the rest of PS2 emulation, see PCSX2's switch to daily builds.


Sources: OpenPS2BIOS (GitHub) · Releases · Compatibility