Fans of Christopher Nolan’s movies will appreciate this one.

Following McCaulay Hudson‘s writeup and release of tools for the Mast1c0re exploit, people have started to showcase emulators and other homebrew games running on the latest PS5 firmware (6.50).

Now before you jump the gun, those are running within the constraints of the PS2 emulator (running itself in the PS4 stack), on the PS5 system. It’s still very cool, and possibly the first public release with actual “fun” usefulness for end users on the PS5! But for all intents and purposes, understand that this is currently limited to running PS2 homebrew (that includes emulators designed for the PS2, as demonstrated below).

Aladdin Sega Genesis version running on an emulator on PS5 through mast1c0re exploit

A Genesis emulator running inside a PS2 emulator running inside the PS4 stack of your PS5. Wow! Insert obvious reference below.

What is Mast1c0re for PS5 and PS4?

Mast1c0re is an unpatched exploit for PS4 and PS5, which leverages a vulnerability in the PS2 emulation layer of Sony’s newer consoles. The vulnerability was disclosed, and described with great detail, by PlayStation hacker CTurt in September last year, but no full “user friendly” implementation was released then.

Back then, CTurt stated Sony had no plan to fix the vulnerability. It has now been fully confirmed that the vulnerability is still here, in the latest PS5 6.50 firmware and in PS4 10.01 as well,  as of February 2023.

Recently released Beta firmwares PS5 7.00 and PS4 10.50 still need to be confirmed, but there’s good reason to believe they are vulnerable as well.

Emulators for PS5 are being released

Scene Hacker Markus95 in particular has shared a PS4/PS5-compatible version of emulator PGEN (Sega Genesis/Megadrive emulator) that will run on all PS5 models up to firmware 6.50 included (and 7.00 very likely as well). And Most likely on PS4 as well, up to the latest firmware (pending confirmation).

You will of course need a legit copy of the exploitable game Okage Shadow King (still available on PSN at the time of writing), and a way to sign your gamesave file (either a Jailbroken PS4, or a Save Wizard subscription, or a Friend with one of those who can sign the savedata for you. Details below).

Scene Veteran Wrozen has also shared a screenshot of Super Mario 64 running on the PS4 through this hack. This is a Native PS2 port of Super Mario 64 (I assume this one?), not an N64 emulator.

Yea it’s a native build of SM64. Unfortunately you don’t get very far in the game before it crashes everytime though.

— Wr0zen (@Wr0zen) February 19, 2023

I’m convinced we’ll see more cool PS2 stuff showing up for this exploit in the days to come. Of course, with minor modifications, all of these releases should work on the latest PS4 firmware (10.01) as well.

Should I buy Okage Shadow King? Should I upgrade my PS4/PS5?

If you’re on a lower PS4/PS5 Firmware, unless PS2 Homebrew and emulators (running on a PS2!) are really exciting for you, I would advise against updating your console, but this is up to you.

However if you happen to be on the latest PS4/PS5 Firmware, and have access to the PSN, I would strongly recommend that you buy Shadow King by now. The game costs 10 bucks, which I feel is an ok price even if all you get to do is play for a few minutes with and old Genesis emulator. Bigger things might not come for this, but at this point I’m feeling that it’s worth it, compared to the risk of missing out: it is a growing possibility that Sony will remove the game from the PSN if they fear that more threatening stuff could come out of this. I am sure there are Sony engineers who are actually enjoying the creativity of hackers to run unsigned code, and I’m sure they’re also not worried as long as it doesn’t allow PS4/PS5 piracy.

Download and run PGEN ( Sega Genesis/Megadrive emulator) for PS5

• Download PGEN PS5 version here
  • Don’t forget to add ROMs, using a tool such as CDGen
• Create and run the Okage exploit following our tutorial here, but instead of the hello world, use the save data (VMC0.card) for the PS2 ELF loader: here
• Once the exploit runs on your PS5, send the iso loader ELF, then the emulator iso to the PS5 with mast1c0re-send-file.py

Known limitations:

• The emulator download link does not include ROMs, you will have to ad them to the iso yourself, using a tool such as CDGen
• PS2 functionality is not perfect and that means there might be significant bugs and glitches (some of which can be seen in Markus95’s video above), even crashes
• This is probably obvious by now, but you need a way to sign the Okage savedata in order to run on your PS5 account. This is “easy” to achieve if you have a Jailbroken PS4, otherwise you might have to ask a Friend (with a Jailbroken PS4) to do it for you, or you need a subscription to paid service Save Wizard (I have never used that service so I cannot vouch for them)

As for people who ask “why would you run old PS2 stuff on your next-gen PS5?”. Because we can.

Source: Markus95