Originally Posted by geekmaster
During operation that is generally correct, but the startup scripts also write to the main partitions when booting both from main and from diags. But they wrap those writes with "mntroot rw" and "mntroot ro" in each case that I have seen.
In diags, various diag test write in the /opt directory tree (which is on the diags boot partition).
Newer firmwares are also know to DELETE stuff from the main boot partition (such as /usr/local).
And of course, some hacks write to the main partition as well (to install startup scripts or keys).
But most changeds are made to /var/local or /mnt/us, as you said.
So in the end that means just about everywhere....
I took a look around my kindle and after an 30 minutes I gave up looking for it. I'm working on reverse engineering the website... I'll figure it out eventually