Programmer manages to run homebrew on PlayStation 2 without hardware mods

Although the PlayStation 2 is now 20 years old, it is still not easy to run unofficial software. This requires, for example, a modchip, or modified memory card, but a programmer has managed to boot with only a disc of homebrew.

The work is in the name of a Security Software Engineer at Microsoft living in England. Christopher “CTurt” Ertl says in his blog that it was an “extremely attractive idea” for him to be able to boot self-assembled disks without further user action. He has shown that this is possible in various YouTube videos since Saturday.

The entry point that CTurt ultimately opted for is the DVD video player. He adjusts the .ifo file, in which metadata is stored. Several calls to this file have no limit on how much data can be returned, which creates the possibility of a buffer overflow. It’s used to start an elf loader that doesn’t verify that that .elf file, which is the equivalent of an .exe file, is signed and trusted.

As proof, CTurt has posted videos of him playing a homebrew Tetris, an NES emulator with Super Mario Bros. and a backup of Shadow of the Colossus. He has also devoted an extensive blog post to the entire process and the source code of his project is online. He concludes by stating that “there is really no reason why this scenario would only work on PS2, as all generations of PlayStation support physical discs.”