- PSP Updates covered this pretty well, so I'll just let them tell you how it is:
"Today hundreds of PSP's will say hello to the world as they run their first piece of homebrew - the "Hello World" application. This will be made possible by a new exploit found that does not require one to own a copy of Grand Theft Auto: Liberty City Stories, but rather load a simple image off of your memory stick. This remarkable demonstration can be executed on 2.0, 2.01, 2.50, 2.60, 2.70, 2.71, and 2.80 firmwares!
If you are stumbling while reading this sentence, I wouldn’t be surprised. I just told you that you are now able to execute a homebrew application on 2.0-2.80 firmware. Now that you know it is possible, you are probably wondering how. With the combined effort of several dedicated users – NOPx86 (provided the original x86 proof of concept), psp250, skylark, joek2100, jimp, cswindle and Fanjita, they have managed to execute the first piece of homebrew on all firmwares above (and including) 2.0!
Less than a week ago, Fanjita dropped by our forums to tell us that a newly discovered exploit is indeed genuine and a usable exploit. This “exploit” started off as a discovery by NOPx86 in libtiff. He managed to find vulnerability and as a result – alter it to crash the PSP and many other image viewers. Fanjita, NOPx86 and the rest of this exploit team have put their hearts and souls into this exploit, and as a result they were able to execute a Hello World application on all PSP’s with the ability to view tiff files (2.0+). This application runs in "User Mode", but kernel mode will be achievable on all firmwares except 2.80.
To execute this “Hello World” application on your 2.0+ PSP, please follow the following directions -
1. Unpack the ZIP file to your PSP's PHOTO folder
2. Navigate to your PSP's PHOTO director and attempt to view the newly transferred picture
Note: You may find that the screen does not show correct (occasionally happens) - just restart your PSP (fully shutoff by holding the power button up) and open the picture again."