Developer shuffle2 has successfully ported PSGrade over to Rockbox. Now you can use the following portable devices to downgrade any PS3 running firmware v3.41 or v3.50: iPod video (5G), iPod (4G), iPod Mini (2G), iPod Nano (1G), and Sansa e200. Currently, only the source code is available therefore, you’ll need to compile it first before you can use it. We’ll keep you posted once we get our hands on the compiled version.
FAQ:
Q: What is Rockbox?
A: Visit the official site for information. Here.
Q: What is the easiest way to get Rockbox onto my device?
A: You can use Rockbox PSGroove Installer. See here or here for installation instructions