AUSMT stands for Auto-Update System Modification Technology. AUSMT enables
patching of webOS system safely, handling the situations like OTA updates
etc.

General information:

  The AUSMT scripts can be called via the package postinst/prerm scripts,
  scripts for patches and themes are located under the patches/ and themes/
  folders. The scripts only need one parameter which is the path for the
  directory holding the patches etc. to be installed into the system. The
  structure of the directory can be seen below.

Directory structure:

  # This is the structure of the patch/theme dir, any of these can be present,
  # i.e. not all are needed. The AUSMT script will install what it finds. 

  binary_patches        # Directory that contains all binary patches
  files_additional      # Directory containing additional system files
  files_replaceable     # Directory containinig replaceable system files
  tweaks_prefs.json     # Preferences file for Tweaks service
  unified_diff.patch    # The patch file in unified diff format
  packages_cache.list   # Cache file that speads up the md5sum fetching

Other related directories:

  # These are meant for apps taking use of patches/themes so that they
  # dont need to be run outside of jail. Even if these gets deleted/modified
  # everything just works or can be recovered with build in recovery.

  # For example Tweaks will have means for user to install his own .patch
  # files or modify the installed patch files and test them. These should 
  # make modifying of existing patches easy.

  # Theme Manager already have means for user to create custom theme from
  # installed themes and allows easy way of user to modify the installed
  # themes through these dirs.

  /media/internal/.patches/
    <id> (user patches installed via patch files for example)
    .<id> (system themes installed via ipk's for example)

  /media/internal/.themes/
    <id> (user themes installed via zip's for example)
    .<id> (system themes installed via ipk's for example)