1# Copyright 2023 The Chromium Authors 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4"""Functionalities to reliably reboot the device.""" 5 6import enum 7 8from typing import Optional 9 10class BootMode(enum.Enum): 11 """Specifies boot mode for device.""" 12 REGULAR = enum.auto() 13 RECOVERY = enum.auto() 14 BOOTLOADER = enum.auto() 15 16 17class StateTransitionError(Exception): 18 """Raised when target does not transition to desired state.""" 19 20 21def boot_device(target_id: Optional[str], 22 mode: BootMode, 23 serial_num: Optional[str] = None, 24 must_boot: bool = False) -> None: 25 """Boot device into desired mode. 26 27 Args: 28 target_id: Optional target_id of device. 29 mode: Desired boot mode. 30 must_boot: Forces device to boot, regardless of current state. 31 Raises: 32 StateTransitionError: When final state of device is not desired. 33 """ 34 # Avoid cycle dependency. 35 # This file will be replaced with serial_boot_device quite soon, later one 36 # should be much more reliable comparing to ffx target list and ssh. So 37 # changing the file structure is not necessary in the current situation. 38 # pylint: disable=cyclic-import, import-outside-toplevel 39 # pylint: disable=wrong-import-position 40 import serial_boot_device 41 if not serial_boot_device.boot_device(target_id, serial_num, mode, 42 must_boot): 43 raise StateTransitionError( 44 f'Could not get device to desired state {mode}.') 45