FAQ about Debian on Plug Computers
Which Plug Computers are supported by Debian?
Debian no longer supports plug computers.
The last release to support these device was Debian 12 (bookworm).
How much space do I need to install Debian?
A normal installation of Debian (i.e. base system plus standard components) will take about 400 MB, so a 1 GB USB stick or SD card is enough (even though more is recommended).
How can I recover if U-Boot is not working?
The U-Boot binary mentioned on the upgrade page was tested and is working. However, in case you flashed a version of U-Boot that does not work, you can use OpenOCD to recover your SheevaPlug.
I don't have documentation on how to recover ("unbrick") using OpenOCD, but the following two pages might be useful: