Ok, so this is the Hello World version of the GripShift exploit, complete with a binary loader and SDK to make your own binaries.
The readme says it all:
Download Hello WorldCode:Hello World on PSP FW 1.52-5.02 The Spartaaaaaaaaaaaaaaaaaaaa!!! Exploit by MaTiAz & FreePlay Instructions ------------ 1. Copy the contents of MS_ROOT into the root of your memory stick. (This will overwrite the first GripShift savegame slot). 2. Launch the US version of GripShift. 3. Load up the game (if it doesn't autoload). 4. See your PSP run unsigned code. :) It'll autoexit after some time. You can use the home button to exit too if you've seen enough. FAQ --- Q: Will this allow downgrading? A: No, because this is an usermode exploit and functions required to downgrade are only available in kernel mode. Q: Why the name? A: Because the original exploit was found by overwriting the player name with "this is spartaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa". Q: Can/Will Sony block this? A: Yes. Q: I wanna make homebrew using the exploit. How? A: Get FreePlay's GS SDK: http://f6y.ath.cx/pspdev/sparta_sdk.zip It has some constraints though, check the readme. The Hello World was written with it. :) Credits ------- Exploit and binary loader: MaTiAz SDK: FreePlay Greets go to Dark_AleX, Mathieulh, jas0nuk, Hellcat, etc. etc. etc, you know.
Download Sparta SDK