Real 2.0 to 1.5 PSP Firmware Downgrader

Well, whaddya know? It's been done.
The seemingly innocuous 64K non-kernal mode buffer overflow exploit recently found in the picture viewer of the version 2.0 PSP firmware has been used to make a downgrade possible. The best we'd seen from this exploit until now was a rather weak version of Pong, but now 2.0 users can actually downgrade their PSP's firmware back to the homebrew-friendly 1.50 version.

There are several files required for the downgrade, including the official Sony 1.50 upgrade file. The process itself, while fairly straightforward, has a few hair-raising moments, such as when the 1.50 "upgrade" gets to 99% completion and then crashes with an error. After a reboot, it errors again, but finally after another restart, the PSP settles in as a fully functional 1.50 unit.

I'm not going into a lot of detail or providing any links, as there's considerable potential for irresponsible use (ie. mass piracy and the odd bricked PSP). Having said that, it's worth noting that ex-WAB team member Yoshihiro is one of the coders responsible. After the WAB team debarcle, Yoshihiro has silenced his critics with this release. No doubt Sony will release a plugged version 2.1 firmware upgrade very soon, and make it a mandatory upgrade for upcoming PSP titles, like GTA: Liberty City Stories. Until then, it seems PSP owners have the ability to upgrade and downgrade between versions 1.50 and 2.0 as they see fit.