Wololo has written a very intuitive tutorial for all the aspiring PSP developers out there. More often than not I see new users over at lan.st posting their findings — some turn up exploitable, some not. Basically if you can overwrite “ra” (return address) you’ve likely stumbled upon a user-mode exploit and you’re set. Bonus points if you find a kernel exploit. But what next once you found said exploit? Wololo answers: Port Half Byte Loader. And once you’ve done that: Email hacks @ psp-hacks with a dot com and share your work with the world. You’ll make your mother proud, my word.
To complete this tutorial, you need basic shell skills, a working pspsdk, a working game exploit and the associated binary loader / hello world, a ruby interpreter, and basic ruby skills (usually, if you know any other scripting language, you’ll figure it out easily, there are not so many changes required).
http://wololo.net/wagic/2010/09/14/port ... e-exploit/