code: def list_installed():
      '''
      Return a list of all installed kernels.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' kernelpkg.list_installed
      '''
      pkg_re = re.compile(r'^{0}-[\d.-]+-{1}$'.format(
          _package_prefix(), _kernel_type()))
      pkgs = __salt__['pkg.list_pkgs'](versions_as_list=True)
      if pkgs is None:
          pkgs = []
  
      result = list(filter(pkg_re.match, pkgs))
      if result is None:
          return []
  
      prefix_len = len(_package_prefix()) + 1
  
      if six.PY2:
          return sorted([pkg[prefix_len:] for pkg in result], cmp=_cmp_version)
      else:
          return sorted([pkg[prefix_len:] for pkg in result], key=functools.cmp_to_key(_cmp_version)f list_installed():
      '''
      Return a list of all installed kernels.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' kernelpkg.list_installed
      '''
      pkg_re = re.compile(r'^{0}-[\d.-]+-{1}$'.format(
          _package_prefix(), _kernel_type()))
      pkgs = __salt__['pkg.list_pkgs'](versions_as_list=True)
      if pkgs is None:
          pkgs = []
  
      result = list(filter(pkg_re.match, pkgs))
      if result is None:
          return []
  
      prefix_len = len(_package_prefix()) + 1
  
      if six.PY2:
          return sorted([pkg[prefix_len:] for pkg in result], cmp=_cmp_version)
      else:
          return sorted([pkg[prefix_len:] for pkg in result], key=functools.cmp_to_key(_cmp_version))
docs: Return a list of all installed kernels.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' kernelpkg.list_installed