[geekmaster]

My K3 units now have firmware version 3.3, but the previous version also used 3 hex digits.

My DX and DXG have firmware version 2.5.8, but the the previous version also used 3 hex digits.

Sir Alex's KDT adds an extra digit that I must remove for the root password on my older kindles.

My newer K4NT and Touch use 4 hex digits. Booting into diagnostics mode on the newer kindles uses a different password than the normal root password.

So, it appears that what root password you need depends on which model of kindle, and on which version of firmware is installed on it, and on which partition you boot from (main mmcblk0p1, or diag mmclbk0p2).

There is not a one-size-fits-all solution for finding the correct root password.

Perhaps your javascript web page should give all three (first try 4 hex digits fionoXXXX, then try mario, then try 3 hex digits fionaXXX), with an emergency alternative (user framework, password mario).