So it's been a big week in the psp scene. First off a buffer overflow was found in the PSP 2.0 firmware and then the PSP firmware downgrader was released. The story starts last year in japan when the psp was originally released with the 1.0 firmware. People began to develop homebrew apps and emulators to run off their memory sticks. Then by the time sony released the PSP in north america it came with the 1.5 firmware. The 1.5 fireware kept the homebrew applications from running but in June of this year they released a loader to load homebrew apps and umd binaries. Then later Fastloader was released to be able to run PSP Iso images. Everything was great in psp land until sony released firmware 1.51,1.52,2.0 which fixed the exploit that was being used to execute apps. Now fast forward to the present and 2.0 is now able to run apps and theres a working downgrader so any psp can be made to run games. The next step will be to see a release of a loader on the 2.0 firmware so that users can run games and use the 2.0 web browser. Luckily my psp had 1.5 on it.

**Update: here's a walkthrough on hackaday for the downgrader.