cts: Refactor cts.py

Noteworthy changes:
- Move Board and its child classes in common/board.py
- Separate flashing and resetting. Flashing used to imply running tests.
- Move up constants up for better visibility
- Change default suite to 'meta'
- Removed redundant code
- Lots of renames (all lower case names, shorter names, etc.)

BUG=none
BRANCH=none
TEST=Ran meta test and verify the results match the expectations

Change-Id: I158d96e2ee104767d25b2e721d5206e528600381
Reviewed-on: https://chromium-review.googlesource.com/383911
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

3 files changed, 433 insertions, 431 deletions

diff --git a/cts/common/__init__.py b/cts/common/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/cts/common/__init__.py
diff --git a/cts/common/board.py b/cts/common/board.py
new file mode 100644
index 0000000000..68d447fb51
--- /dev/null
+++ b/cts/common/board.py
@@ -0,0 +1,319 @@
+# Copyright 2016 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.
+
+from abc import ABCMeta, abstractmethod
+import fcntl
+import os
+import select
+import subprocess as sp
+import time
+
+
+OCD_SCRIPT_DIR = '/usr/local/share/openocd/scripts'
+OPENOCD_CONFIGS = {
+    'stm32l476g-eval': 'board/stm32l4discovery.cfg',
+    'nucleo-f072rb': 'board/st_nucleo_f0.cfg',
+}
+FLASH_OFFSETS = {
+    'stm32l476g-eval': '0x08000000',
+    'nucleo-f072rb': '0x08000000',
+}
+
+
+class Board(object):
+  """Class representing a single board connected to a host machine
+
+  Attributes:
+    board: String containing actual type of board, i.e. nucleo-f072rb
+    config: Directory of board config file relative to openocd's
+        scripts directory
+    hla_serial: String containing board's hla_serial number (if board
+    is an stm32 board)
+    tty_port: String that is the path to the tty port which board's
+        UART outputs to
+    tty: String of file descriptor for tty_port
+  """
+
+  __metaclass__ = ABCMeta  # This is an Abstract Base Class (ABC)
+  def __init__(self, board, hla_serial=None):
+    """Initializes a board object with given attributes
+
+    Args:
+      board: String containing board name
+      hla_serial: Serial number if board's adaptor is an HLA
+    """
+    if not board in OPENOCD_CONFIGS:
+      msg = 'OpenOcd configuration not found for ' + board
+      raise RuntimeError(msg)
+    self.openocd_config = OPENOCD_CONFIGS[board]
+    if not board in FLASH_OFFSETS:
+      msg = 'Flash offset not found for ' + board
+      raise RuntimeError(msg)
+    self.flash_offset = FLASH_OFFSETS[board]
+    self.board = board
+    self.hla_serial = hla_serial
+    self.tty_port = None
+    self.tty = None
+
+  @staticmethod
+  def get_stlink_serials():
+    """Gets serial numbers of all st-link v2.1 board attached to host
+
+    Returns:
+      List of serials
+    """
+    usb_args = ['lsusb', '-v', '-d', '0x0483:0x374b']
+    usb_process = sp.Popen(usb_args, stdout=sp.PIPE, shell=False)
+    st_link_info = usb_process.communicate()[0]
+    st_serials = []
+    for line in st_link_info.split('\n'):
+      if not 'iSerial' in line:
+        continue
+      words = line.split()
+      if len(words) <= 2:
+        continue
+      st_serials.append(words[2].strip())
+    return st_serials
+
+  @abstractmethod
+  def get_serial(self):
+    """Subclass should implement this"""
+    pass
+
+  def send_open_ocd_commands(self, commands):
+    """Send a command to the board via openocd
+
+    Args:
+      commands: A list of commands to send
+    """
+    args = ['openocd', '-s', OCD_SCRIPT_DIR,
+            '-f', self.openocd_config, '-c', 'hla_serial ' + self.hla_serial]
+
+    for cmd in commands:
+      args += ['-c', cmd]
+    args += ['-c', 'shutdown']
+    sp.call(args)
+
+  def build(self, module, ec_dir, debug=False):
+    """Builds test suite module for board
+
+    Args:
+      module: String of the test module you are building,
+        i.e. gpio, timer, etc.
+      ec_dir: String of the ec directory path
+      debug: True means compile in debug messages when building (may
+        affect test results)
+    """
+    cmds = ['make',
+            '--directory=' + ec_dir,
+            'BOARD=' + self.board,
+            'CTS_MODULE=' + module,
+            '-j',
+            '-B']
+
+    if debug:
+      cmds.append('CTS_DEBUG=TRUE')
+
+    print ' '.join(cmds)
+    sp.call(cmds)
+
+  def flash(self):
+    """Flashes board with most recent build ec.bin"""
+    image_path = os.path.join('build', self.board, 'ec.bin')
+    cmd = ['reset_config connect_assert_srst',
+           'init',
+           'reset init',
+           'flash write_image erase %s %s' % (image_path, self.flash_offset)]
+    self.send_open_ocd_commands(cmd)
+
+  def to_string(self):
+    s = ('Type: Board\n'
+         'board: ' + self.board + '\n'
+         'hla_serial: ' + self.hla_serial + '\n'
+         'openocd_config: ' + self.openocd_config + '\n'
+         'tty_port: ' + self.tty_port + '\n'
+         'tty: ' + str(self.tty) + '\n')
+    return s
+
+  def reset(self):
+    """Reset board (used when can't connect to TTY)"""
+    self.send_open_ocd_commands(['init', 'reset init', 'resume'])
+
+  def setup_tty(self):
+    """Call this before trying to call readOutput for the first time.
+    This is not in the initialization because caller only should call
+    this function after serial numbers are setup
+    """
+    self.get_serial()
+    self.reset()
+    self.identify_tty_port()
+
+    # In testing 3 retries is enough to reset board (2 can fail)
+    num_file_setup_retries = 3
+    # In testing, 10 seconds is sufficient to allow board to reconnect
+    reset_wait_time_seconds = 10
+    tty = None
+    try:
+      tty = self.open_tty()
+    # If board was just connected, must be reset to be read from
+    except (IOError, OSError):
+      for i in range(num_file_setup_retries):
+        self.reset()
+        time.sleep(reset_wait_time_seconds)
+        try:
+          tty = self.open_tty()
+          break
+        except (IOError, OSError):
+          continue
+    if not tty:
+      raise ValueError('Unable to read ' + self.name + '\n'
+                       'If you are running cat on a ttyACMx file,\n'
+                       'please kill that process and try again')
+    self.tty = tty
+
+  def read_tty(self):
+    """Read info from a serial port described by a file descriptor
+
+    Return:
+      Bytes that UART has output
+    """
+    buf = []
+    while True:
+      if select.select([self.tty], [], [], 1)[0]:
+        buf.append(os.read(self.tty, 1))
+      else:
+        break
+    result = ''.join(buf)
+    return result
+
+  def identify_tty_port(self):
+    """Saves this board's serial port"""
+    dev_dir = '/dev'
+    id_prefix = 'ID_SERIAL_SHORT='
+    num_reset_tries = 3
+    reset_wait_time_s = 10
+    com_devices = [f for f in os.listdir(dev_dir) if f.startswith('ttyACM')]
+
+    for i in range(num_reset_tries):
+      for device in com_devices:
+        self.tty_port = os.path.join(dev_dir, device)
+        properties = sp.check_output(['udevadm',
+                        'info',
+                        '-a',
+                        '-n',
+                        self.tty_port,
+                        '--query=property'])
+        for line in [l.strip() for l in properties.split('\n')]:
+          if line.startswith(id_prefix):
+            if self.hla_serial == line[len(id_prefix):]:
+              return
+      if i != num_reset_tries - 1: # No need to reset the board the last time
+        self.reset() # May need to reset to connect
+        time.sleep(reset_wait_time_s)
+
+    # If we get here without returning, something is wrong
+    raise RuntimeError('The device dev path could not be found')
+
+  def open_tty(self):
+    """Read available bytes from device dev path"""
+    fd = os.open(self.tty_port, os.O_RDONLY)
+    flag = fcntl.fcntl(fd, fcntl.F_GETFL)
+    fcntl.fcntl(fd, fcntl.F_SETFL, flag | os.O_NONBLOCK)
+    return fd
+
+
+class TestHarness(Board):
+  """Subclass of Board representing a Test Harness
+
+  Attributes:
+    serial_path: Path to file containing serial number
+  """
+
+  def __init__(self, board, serial_path):
+    """Initializes a board object with given attributes
+
+    Args:
+      serial_path: Path to file containing serial number
+    """
+    Board.__init__(self, board=board)
+    self.serial_path = serial_path
+
+  def get_serial(self):
+    """Loads serial number from saved location"""
+    if self.hla_serial:
+      return # serial was already loaded
+    try:
+      with open(self.serial_path, mode='r') as ser_f:
+        self.hla_serial = ser_f.read()
+        return
+    except IOError:
+      msg = ('Your TH board has not been identified.\n'
+             'Connect only TH and run the script --setup, then try again.')
+      raise RuntimeError(msg)
+
+  def save_serial(self):
+    """Saves the TH serial number to a file"""
+    serials = Board.get_stlink_serials()
+    if len(serials) > 1:
+      msg = ('There are more than one test board connected to the host.'
+             '\nConnect only the test harness and remove other boards.')
+      raise RuntimeError(msg)
+    if len(serials) < 1:
+      msg = ('No test boards were found.'
+             '\nTry to run the script outside chroot.')
+      raise RuntimeError(msg)
+
+    serial = serials[0]
+    dir = os.path.dirname(self.serial_path)
+    if not os.path.exists(dir):
+      os.makedirs(dir)
+    with open(self.serial_path, mode='w') as ser_f:
+      ser_f.write(serial)
+      self.hla_serial = serial
+
+    print 'Your TH serial', serial, 'has been saved as', self.serial_path
+    return
+
+
+class DeviceUnderTest(Board):
+  """Subclass of Board representing a DUT board
+
+  Attributes:
+    th: Reference to test harness board to which this DUT is attached
+  """
+
+  def __init__(self, board, th, hla_ser=None):
+    """Initializes a Device Under Test object with given attributes
+
+    Args:
+      board: String containing board name
+      th: Reference to test harness board to which this DUT is attached
+      hla_serial: Serial number if board uses an HLA adaptor
+    """
+    Board.__init__(self, board, hla_serial=hla_ser)
+    self.th = th
+
+  def get_serial(self):
+    """Get serial number.
+
+    Precondition: The DUT and TH must both be connected, and th.hla_serial
+    must hold the correct value (the th's serial #)
+    """
+    if self.hla_serial != None:
+      # serial was already set ('' is a valid serial)
+      return
+
+    serials = Board.get_stlink_serials()
+    dut = [s for s in serials if self.th.hla_serial != s]
+
+    # If len(dut) is 0 then your dut doesn't use an st-link device, so we
+    # don't have to worry about its serial number
+    if  len(dut) != 1:
+      msg = ('Your TH serial number is incorrect, or your have'
+             ' too many st-link devices attached.')
+      raise RuntimeError(msg)
+
+    # Found your other st-link device serial!
+    self.hla_serial = dut[0]
+    return
\ No newline at end of file
diff --git a/cts/cts.py b/cts/cts.py
index 1880ce6018..983b9751d2 100755
--- a/cts/cts.py
+++ b/cts/cts.py
@@ -3,306 +3,41 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# This file is a utility to quickly flash boards
+# A script which builds, flashes, and runs EC CTS
+#
+# Software prerequisites:
+# - openocd version 0.10 or above
+# - lsusb
+# - udevadm
+#
+# To try it out, hook two boards (DEFAULT_TH and DEFAULT_DUT) with USB cables
+# to the host and execute the script:
+#   $ ./cts.py --debug
+# It'll run mock tests. The result will be stored in CTS_TEST_RESULT_DIR.
+
 
 import argparse
 import collections
-import fcntl
 import os
-import select
-import subprocess as sp
 import time
+import common.board as board
 from copy import deepcopy
-from abc import ABCMeta, abstractmethod
 import xml.etree.ElementTree as et
+from twisted.python.syslog import DEFAULT_FACILITY
+
 
 CTS_CORRUPTED_CODE = -2  # The test didn't execute correctly
 CTS_CONFLICTING_CODE = -1 # Error codes should never conflict
 CTS_SUCCESS_CODE = 0
 CTS_COLOR_RED = '#fb7d7d'
 CTS_COLOR_GREEN = '#7dfb9f'
-TH_BOARD = 'stm32l476g-eval'
-OCD_SCRIPT_DIR = '/usr/local/share/openocd/scripts'
+DEFAULT_TH = 'stm32l476g-eval'
+DEFAULT_DUT = 'nucleo-f072rb'
 MAX_SUITE_TIME_SEC = 3
 CTS_DEBUG_START = '[DEBUG]'
 CTS_DEBUG_END = '[DEBUG_END]'
+CTS_TEST_RESULT_DIR = '/tmp/cts'
 
-class Board(object):
-  """Class representing a single board connected to a host machine
-
-  This class is abstract, subclasses must define the updateSerial()
-  method
-
-  Attributes:
-    board: String containing actual type of board, i.e. nucleo-f072rb
-    config: Directory of board config file relative to openocd's
-        scripts directory
-    hla_serial: String containing board's hla_serial number (if board
-    is an stm32 board)
-    tty_port: String that is the path to the tty port which board's
-        UART outputs to
-    _tty_descriptor: String of file descriptor for tty_port
-  """
-
-  configs = {
-      'stm32l476g-eval': 'board/stm32l4discovery.cfg',
-      'nucleo-f072rb': 'board/st_nucleo_f0.cfg'
-  }
-
-  __metaclass__ = ABCMeta  # This is an Abstract Base Class (ABC)
-  def __init__(self, board, hla_serial=None, flash_offset='0x08000000'):
-    """Initializes a board object with given attributes
-
-    Args:
-      board: String containing board name
-      hla_serial: Serial number if board's adaptor is an HLA
-    """
-    self.board = board
-    self.hla_serial = hla_serial
-    self.tty_port = None
-    self._tty_descriptor = None
-    self.flash_offset = flash_offset
-
-  @abstractmethod
-  def updateSerial(self):
-    """Subclass should implement this"""
-    pass
-
-  def sendOpenOcdCommands(self, commands):
-    """Send a command to the board via openocd
-
-    Args:
-      commands: A list of commands to send
-    """
-    args = ['openocd', '-s', OCD_SCRIPT_DIR,
-        '-f', Board.configs[self.board], '-c', 'hla_serial ' + self.hla_serial]
-
-    for cmd in commands:
-      args += ['-c', cmd]
-    args += ['-c', 'shutdown']
-    sp.call(args)
-
-  def make(self, module, ec_dir, debug=False):
-    """Builds test suite module for board
-
-    Args:
-      module: String of the test module you are building,
-        i.e. gpio, timer, etc.
-      ec_dir: String of the ec directory path
-      debug: True means compile in debug messages when building (may
-        affect test results)
-    """
-    cmds = ['make',
-        '--directory=' + ec_dir,
-        'BOARD=' + self.board,
-        'CTS_MODULE=' + module,
-        '-j',
-        '-B']
-
-    if debug:
-      cmds.append('CTS_DEBUG=TRUE')
-
-    print 'EC directory is ' + ec_dir
-    print (
-        'Building module \'' + module + '\' for ' + self.board +
-        'with debug = ' + str(debug))
-    sp.call(cmds)
-
-  def flash(self):
-    """Flashes board with most recent build ec.bin"""
-    flash_cmds = [
-        'reset_config connect_assert_srst',
-        'init',
-        'reset init',
-        'flash write_image erase build/' +
-            self.board +
-            '/ec.bin ' +
-            self.flash_offset,
-        'reset']
-
-    self.sendOpenOcdCommands(flash_cmds)
-
-  def toString(self):
-    s = ('Type: Board\n'
-       'board: ' + self.board + '\n'
-       'hla_serial: ' + self.hla_serial + '\n'
-       'config: ' + Board.configs[self.board] + '\n'
-       'tty_port ' + self.tty_port + '\n'
-       '_tty_descriptor: ' + str(self._tty_descriptor) + '\n')
-    return s
-
-  def reset(self):
-    """Reset board (used when can't connect to TTY)"""
-    self.sendOpenOcdCommands(['init', 'reset init', 'resume'])
-
-  def setupForOutput(self):
-    """Call this before trying to call readOutput for the first time.
-    This is not in the initialization because caller only should call
-    this function after serial numbers are setup
-    """
-    self.updateSerial()
-    self.reset()
-    self._identifyTtyPort()
-
-    # In testing 3 retries is enough to reset board (2 can fail)
-    num_file_setup_retries = 3
-    # In testing, 10 seconds is sufficient to allow board to reconnect
-    reset_wait_time_seconds = 10
-    try:
-      self._getDevFileDescriptor()
-    # If board was just connected, must be reset to be read from
-    except (IOError, OSError):
-      for i in range(num_file_setup_retries):
-        self.reset()
-        time.sleep(reset_wait_time_seconds)
-        try:
-          self._getDevFileDescriptor()
-          break
-        except (IOError, OSError):
-          continue
-    if self._tty_descriptor is None:
-      raise ValueError('Unable to read ' + self.name + '\n'
-               'If you are running cat on a ttyACMx file,\n'
-               'please kill that process and try again')
-
-  def readAvailableBytes(self):
-    """Read info from a serial port described by a file descriptor
-
-    Return:
-      Bytes that UART has output
-    """
-    buf = []
-    while True:
-      if select.select([self._tty_descriptor], [], [], 1)[0]:
-        buf.append(os.read(self._tty_descriptor, 1))
-      else:
-        break
-    result = ''.join(buf)
-    return result
-
-  def _identifyTtyPort(self):
-    """Saves this board's serial port"""
-    dev_dir = '/dev/'
-    id_prefix = 'ID_SERIAL_SHORT='
-    num_reset_tries = 3
-    reset_wait_time_s = 10
-    com_devices = [f for f in os.listdir(
-      dev_dir) if f.startswith('ttyACM')]
-
-    for i in range(num_reset_tries):
-      for device in com_devices:
-        self.tty_port = os.path.join(dev_dir, device)
-        properties = sp.check_output(['udevadm',
-                        'info',
-                        '-a',
-                        '-n',
-                        self.tty_port,
-                        '--query=property'])
-        for line in [l.strip() for l in properties.split('\n')]:
-          if line.startswith(id_prefix):
-            if self.hla_serial == line[len(id_prefix):]:
-              return
-      if i != num_reset_tries - 1: # No need to reset the obard the last time
-        self.reset() # May need to reset to connect
-        time.sleep(reset_wait_time_s)
-
-    # If we get here without returning, something is wrong
-    raise RuntimeError('The device dev path could not be found')
-
-  def _getDevFileDescriptor(self):
-    """Read available bytes from device dev path"""
-    fd = os.open(self.tty_port, os.O_RDONLY)
-    flag = fcntl.fcntl(fd, fcntl.F_GETFL)
-    fcntl.fcntl(fd, fcntl.F_SETFL, flag | os.O_NONBLOCK)
-    self._tty_descriptor = fd
-
-class TestHarness(Board):
-  """Subclass of Board representing a Test Harness
-
-  Attributes:
-    serial_path: Path to file containing serial number
-  """
-
-  def __init__(self, serial_path=None):
-    """Initializes a board object with given attributes
-
-    Args:
-      serial_path: Path to file containing serial number
-    """
-    Board.__init__(self, TH_BOARD)
-    self.serial_path = serial_path
-
-  def updateSerial(self):
-    """Loads serial number from saved location"""
-    if self.hla_serial:
-      return # serial was already loaded
-    try:
-      with open(self.serial_path, mode='r') as ser_f:
-        self.hla_serial = ser_f.read()
-        return
-    except IOError:
-      msg = ('Your th hla_serial may not have been saved.\n'
-           'Connect only your th and run ./cts --setup, then try again.')
-      raise RuntimeError(msg)
-
-  def saveSerial(self):
-    """Saves the th serial number to a file
-
-    Return: the serial number saved
-    """
-    serial = Cts.getSerialNumbers()
-    if len(serial) != 1:
-      msg = ('TH could not be identified.\n'
-           '\nConnect your TH and remove other st-link devices')
-      raise RuntimeError(msg)
-    else:
-      ser = serial[0]
-      if not ser:
-        msg = ('Unable to save serial')
-        raise RuntimeError(msg)
-      if not os.path.exists(os.path.dirname(self.serial_path)):
-        os.makedirs(os.path.dirname(self.serial_path))
-      with open(self.serial_path, mode='w') as ser_f:
-        ser_f.write(ser)
-        self.hla_serial = ser
-        return ser
-
-class DeviceUnderTest(Board):
-  """Subclass of Board representing a DUT board
-
-  Attributes:
-    th: Reference to test harness board to which this DUT is attached
-  """
-
-  def __init__(self, board, th, hla_ser=None, f_offset='0x08000000'):
-    """Initializes a Device Under Test object with given attributes
-
-    Args:
-      board: String containing board name
-      th: Reference to test harness board to which this DUT is attached
-      hla_serial: Serial number if board uses an HLA adaptor
-    """
-    Board.__init__(self, board, hla_serial=hla_ser, flash_offset=f_offset)
-    self.th = th
-
-  def updateSerial(self):
-    """Stores the DUT's serial number.
-
-    Precondition: The DUT and TH must both be connected, and th.hla_serial
-    must hold the correct value (the th's serial #)
-    """
-    if self.hla_serial != None:
-      return # serial was already set ('' is a valid serial)
-    serials = Cts.getSerialNumbers()
-    dut = [s for s in serials if self.th.hla_serial != s]
-    if  len(dut) == 1:
-      self.hla_serial = dut[0]
-      return # Found your other st-link device serial!
-    else:
-      raise RuntimeError('Your TH serial number is incorrect, or your have'
-          ' too many st-link devices attached.')
-    # If len(dut) is 0 then your dut doesn't use an st-link device, so we
-    # don't have to worry about its serial number
 
 class Cts(object):
   """Class that represents a CTS testing setup and provides
@@ -312,7 +47,6 @@ class Cts(object):
     dut: DeviceUnderTest object representing dut
     th: TestHarness object representing th
     module: Name of module to build/run tests for
-    ec_directory: String containing path to EC top level directory
     test_names: List of strings of test names contained in given module
     test_results: Dictionary of results of each test from module, with
         keys being test name strings and values being test result integers
@@ -324,8 +58,7 @@ class Cts(object):
       messages sent while it was running
   """
 
-  def __init__(self, ec_dir,
-               dut='nucleo-f072rb', module='gpio', debug=False):
+  def __init__(self, ec_dir, dut, module, debug=False):
     """Initializes cts class object with given arguments.
 
     Args:
@@ -334,105 +67,66 @@ class Cts(object):
       dut: Name of board to use for DUT
       module: Name of module to build/run tests for
       debug: Boolean that indicates whether or not on-board debug message
-        printing should be enabled when building.
+        printing should be enabled.
     """
-    self.results_dir = '/tmp/cts_results'
+    self.results_dir = CTS_TEST_RESULT_DIR
+    self.ec_dir = ec_dir
     self.module = module
     self.debug = debug
-    self.ec_directory = ec_dir
-    self.th = TestHarness()
-    self.dut = DeviceUnderTest(dut, self.th)  # DUT constructor needs TH
-
-    th_ser_path = os.path.join(
-        self.ec_directory,
-        'build',
-        self.th.board,
-        'th_hla_serial')
-
-    self.module = module
-
-    testlist_path = os.path.join(
-        self.ec_directory,
-        'cts',
-        self.module,
-        'cts.testlist')
-
-    self.test_names = Cts._getMacroArgs(testlist_path, 'CTS_TEST')
+    serial_path = os.path.join(self.ec_dir, 'build', 'cts_th_serial')
+    self.th = board.TestHarness(DEFAULT_TH, serial_path)
+    self.dut = board.DeviceUnderTest(dut, self.th)
+    cts_dir = os.path.join(self.ec_dir, 'cts')
+    testlist_path = os.path.join(cts_dir, self.module, 'cts.testlist')
+    self.test_names = Cts.get_macro_args(testlist_path, 'CTS_TEST')
 
     self.debug_output = {}
     for test in self.test_names:
       self.debug_output[test] = []
 
-    self.th.serial_path = th_ser_path
-
-
-    return_codes_path = os.path.join(self.ec_directory,
-        'cts',
-        'common',
-        'cts.rc')
-
-    self.return_codes = dict(enumerate(Cts._getMacroArgs(
+    return_codes_path = os.path.join(cts_dir, 'common', 'cts.rc')
+    self.return_codes = dict(enumerate(Cts.get_macro_args(
         return_codes_path, 'CTS_RC_')))
 
     self.return_codes[CTS_CONFLICTING_CODE] = 'RESULTS CONFLICT'
     self.return_codes[CTS_CORRUPTED_CODE] = 'CORRUPTED'
-
     self.test_results = collections.OrderedDict()
 
-  def make(self):
-    self.dut.make(self.module, self.ec_directory, self.debug)
-    self.th.make(self.module, self.ec_directory, self.debug)
+  def build(self):
+    """Build images for DUT and TH"""
+    self.dut.build(self.module, self.ec_dir, self.debug)
+    self.th.build(self.module, self.ec_dir, self.debug)
 
-  def flashBoards(self):
+  def flash_boards(self):
     """Flashes th and dut boards with their most recently build ec.bin"""
-    self.updateSerials()
+    self.identify_boards()
     self.th.flash()
     self.dut.flash()
 
   def setup(self):
-    """Saves th serial number if th only is connected.
+    """Setup boards"""
+    self.th.save_serial()
 
-    Return:
-      Serial number that was saved
-    """
-    return self.th.saveSerial()
-
-  def updateSerials(self):
+  def identify_boards(self):
     """Updates serials of both th and dut, in that order (order matters)"""
-    self.th.updateSerial()
-    self.dut.updateSerial()
+    self.th.get_serial()
+    self.dut.get_serial()
 
-  def resetBoards(self):
+  def reset_boards(self):
     """Resets the boards and allows them to run tests
     Due to current (7/27/16) version of sync function,
     both boards must be rest and halted, with the th
     resuming first, in order for the test suite to run
     in sync
     """
-    self.updateSerials()
-    self.th.sendOpenOcdCommands(['init', 'reset halt'])
-    self.dut.sendOpenOcdCommands(['init', 'reset halt'])
-    self.th.sendOpenOcdCommands(['init', 'resume'])
-    self.dut.sendOpenOcdCommands(['init', 'resume'])
-
-  @staticmethod
-  def getSerialNumbers():
-    """Gets serial numbers of all st-link v2.1 board attached to host
-
-    Returns:
-      List of serials
-    """
-    usb_args = ['lsusb', '-v', '-d', '0x0483:0x374b']
-    usb_process = sp.Popen(usb_args, stdout=sp.PIPE, shell=False)
-    st_link_info = usb_process.communicate()[0]
-    st_serials = []
-    for line in st_link_info.split('\n'):
-      if 'iSerial' in line:
-        st_serials.append(line.split()[2].strip())
-    return st_serials
+    self.identify_boards()
+    self.th.send_open_ocd_commands(['init', 'reset halt'])
+    self.dut.send_open_ocd_commands(['init', 'reset halt'])
+    self.th.send_open_ocd_commands(['init', 'resume'])
+    self.dut.send_open_ocd_commands(['init', 'resume'])
 
   @staticmethod
-  def _getMacroArgs(filepath, macro):
+  def get_macro_args(filepath, macro):
     """Get list of args of a certain macro in a file when macro is used
     by itself on a line
 
@@ -441,14 +135,15 @@ class Cts(object):
       macro: String containing text of macro to get args of
     """
     args = []
-    with open(filepath, 'r') as fl:
-      for ln in [ln for ln in fl.readlines(
-      ) if ln.strip().startswith(macro)]:
-        ln = ln.strip()[len(macro):]
-        args.append(ln.strip('()').replace(',', ''))
+    with open(filepath, 'r') as f:
+      for l in f.readlines():
+        if not l.strip().startswith(macro):
+          continue
+        l = l.strip()[len(macro):]
+        args.append(l.strip('()').replace(',', ''))
     return args
 
-  def extractDebugOutput(self, output):
+  def extract_debug_output(self, output):
     """Append the debug messages from output to self.debug_output
 
     Args:
@@ -480,7 +175,7 @@ class Cts(object):
           test_num += 1
       i += 1
 
-  def _parseOutput(self, r1, r2):
+  def parse_output(self, r1, r2):
     """Parse the outputs of the DUT and TH together
 
     Args;
@@ -491,8 +186,8 @@ class Cts(object):
 
     first_corrupted_test = len(self.test_names)
 
-    self.extractDebugOutput(r1)
-    self.extractDebugOutput(r2)
+    self.extract_debug_output(r1)
+    self.extract_debug_output(r2)
 
     for output_str in [r1, r2]:
       test_num = 0
@@ -527,7 +222,7 @@ class Cts(object):
       for test in self.test_names[first_corrupted_test:]:
         self.test_results[test] = CTS_CORRUPTED_CODE
 
-  def _resultsAsString(self):
+  def _results_as_string(self):
     """Takes saved results and returns a duplicate of their dictionary
     with the return codes replaces with their string representation
 
@@ -541,13 +236,13 @@ class Cts(object):
         result[test] = self.return_codes.get(code, 'UNKNOWN %d' % code)
     return result
 
-  def prettyResults(self):
+  def prettify_results(self):
     """Takes saved results and returns a string representation of them
 
     Return: Dictionary similar to self.test_results, but with strings
         instead of error codes
     """
-    res = self._resultsAsString()
+    res = self._results_as_string()
     t_long = max(len(s) for s in res.keys())
     e_max_len = max(len(s) for s in res.values())
 
@@ -560,8 +255,8 @@ class Cts(object):
 
     return pretty_results
 
-  def resultsAsHtml(self):
-    res = self._resultsAsString()
+  def results_as_html(self):
+    res = self._results_as_string()
     root = et.Element('html')
     head = et.SubElement(root, 'head')
     style = et.SubElement(head, 'style')
@@ -607,39 +302,33 @@ class Cts(object):
 
     return et.tostring(root, method='html')
 
-  def resetAndRecord(self):
+  def run(self):
     """Resets boards, records test results in results dir"""
-    self.updateSerials()
-    self.dut.setupForOutput()
-    self.th.setupForOutput()
+    self.identify_boards()
+    self.dut.setup_tty()
+    self.th.setup_tty()
 
-    self.dut.readAvailableBytes()  # clear buffer
-    self.th.readAvailableBytes()
-    bad_cat_message = (
-        'Output missing from boards.\n'
-        'If you are running cat on a ttyACMx file,\n'
-        'please kill that process and try again'
-        )
+    # clear buffers
+    self.dut.read_tty()
+    self.th.read_tty()
 
-    self.resetBoards()
+    self.reset_boards()
 
     time.sleep(MAX_SUITE_TIME_SEC)
 
-    dut_results = self.dut.readAvailableBytes()
-    th_results = self.th.readAvailableBytes()
+    dut_results = self.dut.read_tty()
+    th_results = self.th.read_tty()
 
     if not dut_results or not th_results:
+      msg = ('Output missing from boards. If you have a process reading '
+             'ttyACMx, please kill that process and try again.')
       raise ValueError(bad_cat_message)
 
-    self._parseOutput(dut_results, th_results)
-    pretty_results = self.prettyResults()
-    html_results = self.resultsAsHtml()
+    self.parse_output(dut_results, th_results)
+    pretty_results = self.prettify_results()
+    html_results = self.results_as_html()
 
-    dest = os.path.join(
-        self.results_dir,
-        self.dut.board,
-        self.module + '.html'
-        )
+    dest = os.path.join(self.results_dir, self.dut.board, self.module + '.html')
     if not os.path.exists(os.path.dirname(dest)):
       os.makedirs(os.path.dirname(dest))
 
@@ -648,42 +337,43 @@ class Cts(object):
 
     print pretty_results
 
+
 def main():
-  """Main entry point for cts script from command line"""
-  ec_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..')
+  """Main entry point for CTS script from command line"""
+  ec_dir = os.path.realpath(os.path.join(
+      os.path.dirname(os.path.abspath(__file__)), '..'))
   os.chdir(ec_dir)
 
-  dut_board = 'nucleo-f072rb'  # nucleo by default
-  module = 'gpio'  # gpio by default
-  debug = False
+  dut = DEFAULT_DUT
+  module = 'meta'
 
   parser = argparse.ArgumentParser(description='Used to build/flash boards')
   parser.add_argument('-d',
-            '--dut',
-            help='Specify DUT you want to build/flash')
+                      '--dut',
+                      help='Specify DUT you want to build/flash')
   parser.add_argument('-m',
-            '--module',
-            help='Specify module you want to build/flash')
+                      '--module',
+                      help='Specify module you want to build/flash')
   parser.add_argument('--debug',
-            action='store_true',
-            help='If building, build with debug printing enabled. This may'
-                 'change test results')
+                      action='store_true',
+                      help=('If building, build with debug printing enabled. '
+                            'This may change test results'))
   parser.add_argument('-s',
-            '--setup',
-            action='store_true',
-            help='Connect only the th to save its serial')
+                      '--setup',
+                      action='store_true',
+                      help='Connect only the TH to save its serial')
   parser.add_argument('-b',
-            '--build',
-            action='store_true',
-            help='Build test suite (no flashing)')
+                      '--build',
+                      action='store_true',
+                      help='Build test suite (no flashing)')
   parser.add_argument('-f',
-            '--flash',
-            action='store_true',
-            help='Flash boards with most recent image and record results')
+                      '--flash',
+                      action='store_true',
+                      help='Flash boards with most recent images')
   parser.add_argument('-r',
-            '--reset',
-            action='store_true',
-            help='Reset boards and save test results (no flashing)')
+                      '--run',
+                      action='store_true',
+                      help='Run tests without flashing')
 
   args = parser.parse_args()
 
@@ -691,29 +381,22 @@ def main():
     module = args.module
 
   if args.dut:
-    dut_board = args.dut
-
-  if args.debug:
-    debug = args.debug
+    dut = args.dut
 
-  cts_suite = Cts(ec_dir, module=module, dut=dut_board, debug=debug)
+  cts = Cts(ec_dir, dut=dut, module=module, debug=args.debug)
 
   if args.setup:
-    serial = cts_suite.setup()
-    print 'Your th hla_serial # has been saved as: ' + serial
-
-  elif args.reset:
-    cts_suite.resetAndRecord()
-
+    cts.setup()
   elif args.build:
-    cts_suite.make()
-
+    cts.build()
   elif args.flash:
-    cts_suite.flashBoards()
-
+    cts.flash_boards()
+  elif args.run:
+    cts.run()
   else:
-    cts_suite.make()
-    cts_suite.flashBoards()
+    cts.build()
+    cts.flash_boards()
+    cts.run()
 
 if __name__ == "__main__":
   main()