As I described previously, "todo" server pushes download requests to Kindle, firmware update files are automatically downloaded to the user partition and later applied when Kindle goes to sleep.
If you want to disable automatic update "execution", change /usr/bin/process_update script:
Code:
--- process_update~orig 2009-07-25 22:08:55.000000000 -0700
+++ process_update 2009-07-25 22:41:11.000000000 -0700
@@ -39,9 +39,7 @@
exit 0
fi
- # Start updatewait in background and exit
- ${_UPDATE_WAIT} &
- msg "Started ${_UPDATE_WAIT}" I
+ msg "Auto updates are disabled, exiting..." I
exit 0
fi
Note that manual updates are not disabled - you can still apply downloaded updates from UI.