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PS2 Exploit Allows Running of Unsigned Code
DrEldarion writes "This man has figured out a way to make the PS2 run unsigned code without a modchip. "To make a long story short, the exploit allows anyone with a memory card and
a valid, legal PS1 disc to hijack the boot process and run any piece of code.""
... to get arbitrary files on a memory card? I don't know about you, but *I* don't have anything like that. Will a small industry be created selling pre-altered memory cards?
"I will trust Google to 'do no evil' until the founders no longer run it." Hello Alphabet.
I hadn't even thought about playing non-us games. Shoots a hole through my rant. Are US playstations able to output PAL?
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
Quoted from the page:
PS1DRV parses a file called mc0:/BXDATA-SYSTEM/TITLE.DB (the X represents the
PS2's region code) to load graphic parameters for the PS1 game that was loaded
from the disc drive. There is a catastrophic buffer overflow in the parsing
routine that allows one to overflow the stack and execute arbitrary code by
rewriting the $RA register. If we load up our own TITLE.DB, with an entry for
every PS1 disc that we want to trigger the exploit, then we can take over the
PS2 boot process as soon as the disc is recognized and PS1DRV is executed.
So this hack would allow Backed up and Import games to run on an unmodded system? Basically all one needs is a USB/Mem card interface to put the files on a PS1 memcard and then use a legit PS1 game to boot the machine?
I've got a stack of games from SE Asia that I would love to play on my PS2 and this hack seems like the most non-invasive way to do it.
"There is no time, sir, at which ties do not matter," Jeeves, (Jeeves and the Impending Doom)
I suspect that there will eventually be a PS2 dashboard with functionality similar to EvoX on Xbox. By running unsigned code, you could probably initialize the PS2 HDD - or maybe even Firewire HDD(s) - and load a PS2 native menu with options for then loading Linux, your PS1/2 game backups, native emulators and media players, and homebrew games, demos, and applications. In some ways the Xbox might be better for this; it has newer and more powerful processors, more Ram, and the x86-based architechture is a familiar hardware and software environment to many developers. But the PS2 Firewire port in particular does seem full of potential.
A USB -> PS 1&2 memory card adapter from Lik Sang can be found here.
I have PS2 linux, but the PS2 linux memory card drivers are crippleware, dunno how I'd write to the raw memory card from that environment. Do I need special hardware to program a PS1 memory card? Perhaps now a real PS2 linux distribution will be developed, that will unlock the full capability of the hardware. For example, under Sony's crippleware linux drivers, there is no support for ieee1394 or the hardware MPEG-2 codec. r4lv3k
Calm down! First of all, if I understand correctly, this exploit takes a valid PSX game, stops it from booting, then loads 'any piece of code' _right off the memory card_. It does not provide for any sort of disc swap. This means you can not use it to load any game which the PS2 would not normally load; you can only load an .elf (I think) file which is _on the memory card_.
:)
Meaning this is only useful for _small_ homebrew apps.
Second of all, it is unlikely this will ever be expanded to allow loading out-of-region/copied games. Sony uses a special copy-protection trick... as far as I know it involves a tiny sector in the beginning of a disc which has a checksum of zero. Inside this sector there is the data containing region information (should be impossible to contain any data if the checksum is zero, but it does). CD burners 'correct' this sector by writing the actual checksum, and hence PSX/PS2 games cannot be copied correctly. When you insert any disc into a PSX or PS2, the unmodified hardware checks that sector to see if the checksum is zero and if the region code is correct, and refuses to read any further data, _no matter what_, if that sector isn't just right. A mod chip works by injecting the correct data into the CPU at the right time.
This means, even though you could use the exploit to read abritrary data off something other than the disc the console was going to read from, you can't read it from another disc: if you eject that valid disc and put in another, the PS2 is going to check that special sector. Unless I misunderstand something, this exploit _does not_ address that, and so you can only load code off a memory card. Maybe someone will come out with a way to load stuff off a hard drive with it, but it's unlikely you'll ever be able to load stuff off a different (invalid) disc.
I should also point out that the terms 'signed' and 'unsigned' are possibly incorrect for this sort of thing, as the copy protection isn't really in the form of an encrypted key, per se... just a crazy sector containing simple data, with a checksum of zero.
This is how it has been explained to me over the years by a variety of people and is AFAIK the generally accepted understanding of the Sony copy protection method. I have never worked for Sony so I cannot verify it. If you have any corrections here, feel free to speak up
~ Aero
The c-64 games I wrote in the late eighties displayed over 40 flicker-free hardware sprites. The basic technique was to reposition the hardware position settings of each of the 8 hardware sprites with the raster interrupt. The tricky bit was sorting the raster lines for the handler (I used a bucket sort on the stack).
When doing scrolling you set a bit to make the borders come in so you wouldn't see the scrolling characters just pop on. If you used the raster interrupt to set this off again when the raster scan was in this region, the whole border disappeared.
I am doing equivalent hacks these days for the PS2, NGC and XBOX to get extra performance when I need it. Yes it is fancy ASM hacking - and no, they don't stop you doing it.
The difference is that these aren't open platforms - which sucks. Hard.
I don't typically read or post on /. these days, but since you folks were so kind as to saturate my cable connection :P, I read through the comments and wanted to clarify a few things:
Oh, about all the Linux posts: I've been developing a way to get ps2linux to boot without Sony's kit, and it will all tie into this. No ETA on that yet.
Cheers to all who've stepped up with the positive posts.