PW2 Strange diags partition issue

[evilReader]

So I've been playing around on an old Paperwhite 2 (5.12.2.2), and while I was trying to install the rescue pack, it just kept failing. The log said it wasn't able to find the /etc/shadow file after it mounted the diags partition which was strange.

Going into a shell I check what the contents of the diags partition were and it was empty save for a single file called 'hjkl', the only contents of which were:

version:0
location:

I guessed at this point that for whatever reason the diags partition got wiped so I re-flashed it over fastboot (using the diags image from https://www.mobileread.com/forums/sh...d.php?t=342535). I checked to make sure it worked properly and I was able to get into diags mode using a serial cable.

After rebooting into normal mode again, I try to install the rescue pack, same error, just the one 'hjkl' file in the partition.

So looking wherever else was using the diags partition, on boot '/etc/upstart/filesystems_nh.conf' tries to mount diags to /usr/share/nh which looks to be used by some 'nhinstaller', and if it fails to mount it tries to format the partition and recreate it before attempting to mount again. It logs this during boot so that didn't look to be happening.

At this point I'm at a dead end. Did amazon decide to remove the diags partition in the latest PW2 update or something?