#!/usr/bin/env python3
# Copyright 2018 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Verify RO only boots valid RW and not corrupt/ dev signed RW"""

from __future__ import print_function

import sys
import time

import common
import hammerd_api # pylint: disable=import-error


# Before this test, please flash MP-signed locked image (staff.bin)
def main(argv):
  if argv:
    sys.exit('Test takes no args!')
  updater = hammerd_api.FirmwareUpdater(common.BASE_VENDOR_ID,
                                        common.BASE_PRODUCT_ID,
                                        common.BASE_USB_PATH)
  # Load EC image.
  with open(common.RW_VALID, 'rb') as f:
    ec_image = f.read()
  updater.LoadEcImage(ec_image)

  common.disable_hammerd()
  # Update to invalid RW with corrupt bytes at begining of image
  image_desc = 'Update to invalid RW with corrupt bytes at begining of image'
  update_invalid_rw(updater, common.RW_CORRUPT_FIRST_BYTE, image_desc)

  # Restore to valid RW
  restore_valid_rw(updater, common.RW_VALID)

  # Update to invalid RW with corrupt bytes at end of image
  image_desc = 'Update to invalid RW with corrupt bytes at end of image'
  update_invalid_rw(updater, common.RW_CORRUPT_LAST_BYTE, image_desc)

  # Restore to valid RW
  restore_valid_rw(updater, common.RW_VALID)


def init_before_updaterw(updater):
  common.connect_usb(updater)
  print('EC information:')
  pdu_resp = updater.GetFirstResponsePdu().contents
  print('PDU Response: %s' % pdu_resp)
  print('Current section before updating RW: %s' % updater.CurrentSection())
  assert updater.CurrentSection() == 1, 'Running section should be 1 (RW)'


def transfer_rw(updater, image):
  with open(image, 'rb') as f:
    ec_image = f.read()
  updater.LoadEcImage(ec_image)
  print('Transferring RW')
  updater.TransferImage(1)
  updater.SendSubcommand(hammerd_api.UpdateExtraCommand.ImmediateReset)
  updater.CloseUsb()
  time.sleep(0.5)
  common.connect_usb(updater)


def update_invalid_rw(updater, image, image_desc):
  init_before_updaterw(updater)
  common.reset_stay_ro(updater)
  unlock_rw(updater)
  print(image_desc)
  transfer_rw(updater, image)
  updater.SendSubcommand(hammerd_api.UpdateExtraCommand.JumpToRW)
  updater.CloseUsb()
  # If successful (it should not be), jump to RW resets the base.
  common.connect_usb(updater)
  updater.SendFirstPdu()
  updater.SendDone()
  print('Current section-invalid RW update: %s' % updater.CurrentSection())
  assert updater.CurrentSection() == 0, 'Running section should be 0 (RO)'


def restore_valid_rw(updater, image):
  print('Restoring to valid RW')
  transfer_rw(updater, image)
  updater.SendSubcommand(hammerd_api.UpdateExtraCommand.JumpToRW)
  time.sleep(2)
  updater.CloseUsb()
  time.sleep(0.5)
  # Jump to RW resets the base. Need to reconnect
  common.connect_usb(updater)
  updater.SendFirstPdu()
  updater.SendDone()
  print('Current section after valid RW update: %s' % updater.CurrentSection())
  assert updater.CurrentSection() == 1, 'Running section should be 1 (RW)'
  common.sim_disconnect_connect(updater)


def get_wp_status(updater):
  wp_rw = (get_flash_protection(updater) & common.EC_FLASH_PROTECT_RW_NOW) > 0
  return wp_rw


def get_flash_protection(updater):
  pdu_resp = updater.GetFirstResponsePdu().contents
  return pdu_resp.flash_protection


def unlock_rw(updater):
  # Check if RW is locked and unlock if needed
  wp_rw = (get_flash_protection(updater) & common.EC_FLASH_PROTECT_RW_NOW) > 0
  print('WP status:  %s' %str(wp_rw))
  if wp_rw:
    print('Need to unlock RW')
    unlocked = updater.UnlockRW()
    assert unlocked == 1, 'Failed to unlock RW'
    common.reset_stay_ro(updater)

if __name__ == '__main__':
  sys.exit(main(sys.argv[1:]))