I noticed that I forgot to release a script to extract Kindle firmware updates. So I decided to combine it with update maker, make it a bit more flexible and add support for K2 (though I can't test this part). The result is this script
The simplest usage is to convert a shell script to an "update" to run it on the device. For example, to add a custom screensaver
kindle_update_tool.py e update_mmm.bin
Extract a Kindle or Kindle 2 firmware update file. Outputs a .tgz file with decrypted content.
kindle_update_tool.py m [-k2] name file1 [file2 ...]
Makes a Kindle or Kindle 2 (if -k2 specified) OTA firmware update file from the list of files.
"name" is the update file suffix (final file will be called update_name.bin).
Any file with .sh extension will be marked as a shell script to be executed.