docs: def InstallDriver(kext_path):
    """Calls into the IOKit to load a kext by file-system path.
  
    Apple kext API doco here:
      http://developer.apple.com/library/mac/#documentation/IOKit/Reference/
        KextManager_header_reference/Reference/reference.html
  
    Args:
      kext_path: Absolute or relative POSIX path to the kext.
  
    Raises:
      OSError: On failure to load the kext.
    """
    km = objc.KextManager()
  
    cf_kext_path = km.PyStringToCFString(kext_path)
    kext_url = km.dll.CFURLCreateWithFileSystemPath(
        objc.CF_DEFAULT_ALLOCATOR, cf_kext_path, objc.POSIX_PATH_STYLE, True)
    status = km.iokit.KextManagerLoadKextWithURL(kext_url, None)
  
    km.dll.CFRelease(kext_url)
    km.dll.CFRelease(cf_kext_path)
    if status is not objc.OS_SUCCESS:
      raise OSError("Failed to load kext at {0}: {1}".format(kext_path, status))