For those of you with 4th generation “click-wheel” iPods itching to replace the code on the little white box with Linux so you could, what, run Linux apps on a tiny little white box with a tiny little screen and a wheel that clicks, now you can!
What makes the story interesting though isn’t that you can, but how it was cracked:
(Bernard) Leach had already cracked the code of the component which controls the wheel’s clicking sound. In order to work out how the bootloader code worked, (Nils) Schneider played it as sound through the click wheel.
The clicks were recorded and converted back into code. Some 20 hours and one sound-proof box later, the puzzle was solved and the iPod was capable of running new games as well as a Linux OS.