First step on the way to your very own Kindleberry Pi is downgrading your Kindle:

  1. Turn on the airplane mode

    While jailbreak itself should survive firmware updates, custom hacks it enables might not. Proceed at your own risk.

  2. Download firmware

    At the time of writing, the most recent jailbreak works with firmware version 5.4.4.2. With a bit of URL trickery, we can download it from Amazon.

  3. Copy the firmware to the Kindle root directory.

    Do not disconnect or eject your Kindle just yet. Instead, restart it by long pressing the power button on the bottom edge. Update progress dialogue should appear.

  4. Confirm that downgrade went well

    From Home screen, tap Menu, then Settings.
    From Settings screen, tap Menu again, then Device Info.
    Firmware Version:Kindle 5.4.4.2 means we are golden and ready to jailbreak.

  5. Make sure your Kindle is still yours

    It seems like downgrading can unregister your device. If that's the case, simply register it again.