Using Kexec Allows Starting Linux In PlayStation 4

jones_supa writes: Team fail0verflow, the hacker group who made Sony PlayStation 4, has introduced another method to start Linux in the game console. Instead of the previous exploit which was based on a security hole in an old PS4 firmware version, the new trick allows a kexec call to start Linux through Orbis OS (the FreeBSD-based system software of PS4). The code can be found in GitHub. Maybe this will lead to more and better PlayStation clusters.

Comments

Re:What?

[jones_supa]

Facepalm. It seems that both I and Timothy are sleeping on the wheel. :D

Anyway, I would also add to the summary that you need some another way to actually make the kexec call. Over at PSXHAX there was posted a new BadIRET exploit last Wednesday. Maybe it works.

Re:PS3 clusters were *briefly* interesting...

[Dutch Gun]

Unfortunately, while it had tremendous capability to run certain traditional HPC jobs, it wasn't that good a match for what game developers needed most...

Which is???

The cell broadband chip was originally designed to be used for multimedia processing. It had amazing vector processing capabilities, but videogame code doesn't have a lot of cases where you're crunching large amounts of data using simple algorithms, as with video decoding. As it turns out, typical game code tends to have lots of branches, special cases, one offs, etc (physics, AI, pathfinding, skeletal animation, etc). I imagine this is also why the major manufacturers returned to a more traditional x86-64 architecture instead of the PPC. The PowerPC had crappy out-of-order processing and branch prediction, and suffers rather badly when faced with branch-heavy code.

In other words, most videogames require processors that can deal efficiently with branching code and lots of small, irregular data sets via caching. That's pretty much the exact opposite of what the cell is good at. There were some some devs who went through some fairly heroic efforts to squeeze all they could out of the cell, but in the end, all that effort netted about the same results as another couple of general-purpose CPU cores that took almost no coding effort. Most game developers I know disliked the PS3, because to get the same performance as on the Xbox 360 required about 10x the effort.