How did Edison manage to set the cpu clock to 333 MHz? - PSP3D.com - Sony PlayStation Portable News, Homebrew, Hacks, Reviews, Videos, Mods, Forums

Homer · #1 (**permalink**) 01-22-2006, 12:37 PM

Hi there!
I have another question... This time it's about the CheatDevice. I just wondered how the heck Edison managed to set the cpu clock freq to 333 MHz? Don't you need kernel access for that?
I know how to check what the freq is at, but the command for changing it didn't seem to work.

Here's the command to check the current cpu clock freq:

Code:

int sceGetCpuClockFrequency()
{
	register int lret asm("$2");
	asm("syscall 0x219F;"
			: "=r" (lret)
		);
		return(lret);
}

And here's the non-working set cpu clock freq:

Code:

int sceSetCpuClockFrequency(int cpu, int ram, int bus)
// cpu = 1 - 333
// ram = 1 - 333
// bus = 1 - 167
{
	register int lret asm("$2");
	asm("syscall 0x21A7;"      
	    : "=r" (lret)
      : "r" (cpu), "r" (ram), "r" bus()
      );
}

Btw, I got the correct sycall addresses from here http://home.zhwin.ch/~oem/syscalls_game_2.00.txt

KyleNic · #2 (**permalink**) 01-22-2006, 12:43 PM

Quote:

Originally Posted by Matte

Don't you need kernel access for that?

No you dont need KERNAL mode for that as the GTA HACK is USermode only and doesnt have access to KERNAL

Homer · #3 (**permalink**) 01-22-2006, 12:49 PM

Okay.. That's what I thought.
But does anyone (fanjita) know the command he used?

Homer · #4 (**permalink**) 01-23-2006, 04:14 PM

I'm still wondering this... (also known as bump)

Percival · #5 (**permalink**) 01-23-2006, 04:29 PM

You're missing something.
Try:

Code:

int sceSetCpuClockFrequency(int cpu, int ram, int bus)
// cpu = 1 - 333
// ram = 1 - 333
// bus = 1 - 167
{
  register int lret asm("$2");
  register int lcpu asm("$4") = cpu;
  register int lram asm("$5") = ram;
  register int lbus asm("$6") = bus;

  asm("syscall 0x21A7"
      : "=r" (lret)
      : "r" (lcpu), "r" (lram), "r" (lbus)
      );

  return(lret);
}

Of course, no guarantee that this works.
::Edit:: syscall wasn't right.. changed to 0x21A7

Homer · #6 (**permalink**) 01-23-2006, 04:46 PM

Actually, I believe that sysall could've been right. I found out that there was one so that you could change the cpu's, ram's and bus' speed while the other was only for the cpu.
Thank you anyways, I'll test it right away

Ohh.. I see, you wrote the wrong syscall? Anyway, what I said still is true.

Percival · #7 (**permalink**) 01-23-2006, 04:52 PM

Yeah that is what I meant, I copied the wrong syscall.
But did it work? I'm also interested in this

Homer · #8 (**permalink**) 01-23-2006, 05:09 PM

Sorry, no... It didn't work. Hmm... I'll mess some with it, I'll be sure to let you know if I end up with something good

Sin · #9 (**permalink**) 01-23-2006, 05:55 PM

KyleNic

I love your double posters .Gif img

Homer · #10 (**permalink**) 01-23-2006, 06:00 PM

Wtf??
Couldn't you just have sent him a PM saying that instead of spamming the forums?