test/py/u_boot_utils.py - platform/external/u-boot - Gitiles

 # SPDX-License-Identifier: GPL-2.0
 # Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.

 """
 Utility code shared across multiple tests.
 """

 import hashlib
 import inspect
 import os
 import os.path
 import pathlib
 import signal
 import sys
 import time
 import re
 import pytest

 def md5sum_data(data):
     """Calculate the MD5 hash of some data.

     Args:
         data: The data to hash.

     Returns:
         The hash of the data, as a binary string.
     """

     h = hashlib.md5()
     h.update(data)
     return h.digest()

 def md5sum_file(fn, max_length=None):
     """Calculate the MD5 hash of the contents of a file.

     Args:
         fn: The filename of the file to hash.
         max_length: The number of bytes to hash. If the file has more
             bytes than this, they will be ignored. If None or omitted, the
             entire file will be hashed.

     Returns:
         The hash of the file content, as a binary string.
     """

     with open(fn, 'rb') as fh:
         if max_length:
             params = [max_length]
         else:
             params = []
         data = fh.read(*params)
     return md5sum_data(data)

 class PersistentRandomFile:
     """Generate and store information about a persistent file containing
     random data."""

     def __init__(self, u_boot_console, fn, size):
         """Create or process the persistent file.

         If the file does not exist, it is generated.

         If the file does exist, its content is hashed for later comparison.

         These files are always located in the "persistent data directory" of
         the current test run.

         Args:
             u_boot_console: A console connection to U-Boot.
             fn: The filename (without path) to create.
             size: The desired size of the file in bytes.

         Returns:
             Nothing.
         """

         self.fn = fn

         self.abs_fn = u_boot_console.config.persistent_data_dir + '/' + fn

         if os.path.exists(self.abs_fn):
             u_boot_console.log.action('Persistent data file ' + self.abs_fn +
                 ' already exists')
             self.content_hash = md5sum_file(self.abs_fn)
         else:
             u_boot_console.log.action('Generating ' + self.abs_fn +
                 ' (random, persistent, %d bytes)' % size)
             data = os.urandom(size)
             with open(self.abs_fn, 'wb') as fh:
                 fh.write(data)
             self.content_hash = md5sum_data(data)

 def attempt_to_open_file(fn):
     """Attempt to open a file, without throwing exceptions.

     Any errors (exceptions) that occur during the attempt to open the file
     are ignored. This is useful in order to test whether a file (in
     particular, a device node) exists and can be successfully opened, in order
     to poll for e.g. USB enumeration completion.

     Args:
         fn: The filename to attempt to open.

     Returns:
         An open file handle to the file, or None if the file could not be
             opened.
     """

     try:
         return open(fn, 'rb')
     except:
         return None

 def wait_until_open_succeeds(fn):
     """Poll until a file can be opened, or a timeout occurs.

     Continually attempt to open a file, and return when this succeeds, or
     raise an exception after a timeout.

     Args:
         fn: The filename to attempt to open.

     Returns:
         An open file handle to the file.
     """

     for i in range(100):
         fh = attempt_to_open_file(fn)
         if fh:
             return fh
         time.sleep(0.1)
     raise Exception('File could not be opened')

 def wait_until_file_open_fails(fn, ignore_errors):
     """Poll until a file cannot be opened, or a timeout occurs.

     Continually attempt to open a file, and return when this fails, or
     raise an exception after a timeout.

     Args:
         fn: The filename to attempt to open.
         ignore_errors: Indicate whether to ignore timeout errors. If True, the
             function will simply return if a timeout occurs, otherwise an
             exception will be raised.

     Returns:
         Nothing.
     """

     for _ in range(100):
         fh = attempt_to_open_file(fn)
         if not fh:
             return
         fh.close()
         time.sleep(0.1)
     if ignore_errors:
         return
     raise Exception('File can still be opened')

 def run_and_log(u_boot_console, cmd, ignore_errors=False, stdin=None, env=None):
     """Run a command and log its output.

     Args:
         u_boot_console: A console connection to U-Boot.
         cmd: The command to run, as an array of argv[], or a string.
             If a string, note that it is split up so that quoted spaces
             will not be preserved. E.g. "fred and" becomes ['"fred', 'and"']
         ignore_errors: Indicate whether to ignore errors. If True, the function
             will simply return if the command cannot be executed or exits with
             an error code, otherwise an exception will be raised if such
             problems occur.
         stdin: Input string to pass to the command as stdin (or None)
             env: Environment to use, or None to use the current one

     Returns:
         The output as a string.
     """
     if isinstance(cmd, str):
         cmd = cmd.split()
     runner = u_boot_console.log.get_runner(cmd[0], sys.stdout)
     output = runner.run(cmd, ignore_errors=ignore_errors, stdin=stdin, env=env)
     runner.close()
     return output

 def run_and_log_expect_exception(u_boot_console, cmd, retcode, msg):
     """Run a command that is expected to fail.

     This runs a command and checks that it fails with the expected return code
     and exception method. If not, an exception is raised.

     Args:
         u_boot_console: A console connection to U-Boot.
         cmd: The command to run, as an array of argv[].
         retcode: Expected non-zero return code from the command.
         msg: String that should be contained within the command's output.
     """
     try:
         runner = u_boot_console.log.get_runner(cmd[0], sys.stdout)
         runner.run(cmd)
     except Exception:
         assert retcode == runner.exit_status
         assert msg in runner.output
     else:
         raise Exception("Expected an exception with retcode %d message '%s',"
                         "but it was not raised" % (retcode, msg))
     finally:
         runner.close()

 ram_base = None
 def find_ram_base(u_boot_console):
     """Find the running U-Boot's RAM location.

     Probe the running U-Boot to determine the address of the first bank
     of RAM. This is useful for tests that test reading/writing RAM, or
     load/save files that aren't associated with some standard address
     typically represented in an environment variable such as
     ${kernel_addr_r}. The value is cached so that it only needs to be
     actively read once.

     Args:
         u_boot_console: A console connection to U-Boot.

     Returns:
         The address of U-Boot's first RAM bank, as an integer.
     """

     global ram_base
     if u_boot_console.config.buildconfig.get('config_cmd_bdi', 'n') != 'y':
         pytest.skip('bdinfo command not supported')
     if ram_base == -1:
         pytest.skip('Previously failed to find RAM bank start')
     if ram_base is not None:
         return ram_base

     with u_boot_console.log.section('find_ram_base'):
         response = u_boot_console.run_command('bdinfo')
         for l in response.split('\n'):
             if '-> start' in l or 'memstart    =' in l:
                 ram_base = int(l.split('=')[1].strip(), 16)
                 break
         if ram_base is None:
             ram_base = -1
             raise Exception('Failed to find RAM bank start in `bdinfo`')

     # We don't want ram_base to be zero as some functions test if the given
     # address is NULL (0). Besides, on some RISC-V targets the low memory
     # is protected that prevents S-mode U-Boot from access.
     # Let's add 2MiB then (size of an ARM LPAE/v8 section).

     ram_base += 1024 * 1024 * 2

     return ram_base

 class PersistentFileHelperCtxMgr(object):
     """A context manager for Python's "with" statement, which ensures that any
     generated file is deleted (and hence regenerated) if its mtime is older
     than the mtime of the Python module which generated it, and gets an mtime
     newer than the mtime of the Python module which generated after it is
     generated. Objects of this type should be created by factory function
     persistent_file_helper rather than directly."""

     def __init__(self, log, filename):
         """Initialize a new object.

         Args:
             log: The Logfile object to log to.
             filename: The filename of the generated file.

         Returns:
             Nothing.
         """

         self.log = log
         self.filename = filename

     def __enter__(self):
         frame = inspect.stack()[1]
         module = inspect.getmodule(frame[0])
         self.module_filename = module.__file__
         self.module_timestamp = os.path.getmtime(self.module_filename)

         if os.path.exists(self.filename):
             filename_timestamp = os.path.getmtime(self.filename)
             if filename_timestamp < self.module_timestamp:
                 self.log.action('Removing stale generated file ' +
                     self.filename)
                 pathlib.Path(self.filename).unlink()

     def __exit__(self, extype, value, traceback):
         if extype:
             try:
                 pathlib.Path(self.filename).unlink()
             except Exception:
                 pass
             return
         logged = False
         for _ in range(20):
             filename_timestamp = os.path.getmtime(self.filename)
             if filename_timestamp > self.module_timestamp:
                 break
             if not logged:
                 self.log.action(
                     'Waiting for generated file timestamp to increase')
                 logged = True
             os.utime(self.filename)
             time.sleep(0.1)

 def persistent_file_helper(u_boot_log, filename):
     """Manage the timestamps and regeneration of a persistent generated
     file. This function creates a context manager for Python's "with"
     statement

     Usage:
         with persistent_file_helper(u_boot_console.log, filename):
             code to generate the file, if it's missing.

     Args:
         u_boot_log: u_boot_console.log.
         filename: The filename of the generated file.

     Returns:
         A context manager object.
     """

     return PersistentFileHelperCtxMgr(u_boot_log, filename)

 def crc32(u_boot_console, address, count):
     """Helper function used to compute the CRC32 value of a section of RAM.

     Args:
         u_boot_console: A U-Boot console connection.
         address: Address where data starts.
         count: Amount of data to use for calculation.

     Returns:
         CRC32 value
     """

     bcfg = u_boot_console.config.buildconfig
     has_cmd_crc32 = bcfg.get('config_cmd_crc32', 'n') == 'y'
     assert has_cmd_crc32, 'Cannot compute crc32 without CONFIG_CMD_CRC32.'
     output = u_boot_console.run_command('crc32 %08x %x' % (address, count))

     m = re.search('==> ([0-9a-fA-F]{8})$', output)
     assert m, 'CRC32 operation failed.'

     return m.group(1)

 def waitpid(pid, timeout=60, kill=False):
     """Wait a process to terminate by its PID

     This is an alternative to a os.waitpid(pid, 0) call that works on
     processes that aren't children of the python process.

     Args:
         pid: PID of a running process.
         timeout: Time in seconds to wait.
         kill: Whether to forcibly kill the process after timeout.

     Returns:
         True, if the process ended on its own.
         False, if the process was killed by this function.

     Raises:
         TimeoutError, if the process is still running after timeout.
     """
     try:
         for _ in range(timeout):
             os.kill(pid, 0)
             time.sleep(1)

         if kill:
             os.kill(pid, signal.SIGKILL)
             return False

     except ProcessLookupError:
         return True

     raise TimeoutError(
         "Process with PID {} did not terminate after {} seconds."
         .format(pid, timeout)
     )
	# SPDX-License-Identifier: GPL-2.0
	# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.

	"""
	Utility code shared across multiple tests.
	"""

	import hashlib
	import inspect
	import os
	import os.path
	import pathlib
	import signal
	import sys
	import time
	import re
	import pytest

	def md5sum_data(data):
	"""Calculate the MD5 hash of some data.

	Args:
	data: The data to hash.

	Returns:
	The hash of the data, as a binary string.
	"""

	h = hashlib.md5()
	h.update(data)
	return h.digest()

	def md5sum_file(fn, max_length=None):
	"""Calculate the MD5 hash of the contents of a file.

	Args:
	fn: The filename of the file to hash.
	max_length: The number of bytes to hash. If the file has more
	bytes than this, they will be ignored. If None or omitted, the
	entire file will be hashed.

	Returns:
	The hash of the file content, as a binary string.
	"""

	with open(fn, 'rb') as fh:
	if max_length:
	params = [max_length]
	else:
	params = []
	data = fh.read(*params)
	return md5sum_data(data)

	class PersistentRandomFile:
	"""Generate and store information about a persistent file containing
	random data."""

	def __init__(self, u_boot_console, fn, size):
	"""Create or process the persistent file.

	If the file does not exist, it is generated.

	If the file does exist, its content is hashed for later comparison.

	These files are always located in the "persistent data directory" of
	the current test run.

	Args:
	u_boot_console: A console connection to U-Boot.
	fn: The filename (without path) to create.
	size: The desired size of the file in bytes.

	Returns:
	Nothing.
	"""

	self.fn = fn

	self.abs_fn = u_boot_console.config.persistent_data_dir + '/' + fn

	if os.path.exists(self.abs_fn):
	u_boot_console.log.action('Persistent data file ' + self.abs_fn +
	' already exists')
	self.content_hash = md5sum_file(self.abs_fn)
	else:
	u_boot_console.log.action('Generating ' + self.abs_fn +
	' (random, persistent, %d bytes)' % size)
	data = os.urandom(size)
	with open(self.abs_fn, 'wb') as fh:
	fh.write(data)
	self.content_hash = md5sum_data(data)

	def attempt_to_open_file(fn):
	"""Attempt to open a file, without throwing exceptions.

	Any errors (exceptions) that occur during the attempt to open the file
	are ignored. This is useful in order to test whether a file (in
	particular, a device node) exists and can be successfully opened, in order
	to poll for e.g. USB enumeration completion.

	Args:
	fn: The filename to attempt to open.

	Returns:
	An open file handle to the file, or None if the file could not be
	opened.
	"""

	try:
	return open(fn, 'rb')
	except:
	return None

	def wait_until_open_succeeds(fn):
	"""Poll until a file can be opened, or a timeout occurs.

	Continually attempt to open a file, and return when this succeeds, or
	raise an exception after a timeout.

	Args:
	fn: The filename to attempt to open.

	Returns:
	An open file handle to the file.
	"""

	for i in range(100):
	fh = attempt_to_open_file(fn)
	if fh:
	return fh
	time.sleep(0.1)
	raise Exception('File could not be opened')

	def wait_until_file_open_fails(fn, ignore_errors):
	"""Poll until a file cannot be opened, or a timeout occurs.

	Continually attempt to open a file, and return when this fails, or
	raise an exception after a timeout.

	Args:
	fn: The filename to attempt to open.
	ignore_errors: Indicate whether to ignore timeout errors. If True, the
	function will simply return if a timeout occurs, otherwise an
	exception will be raised.

	Returns:
	Nothing.
	"""

	for _ in range(100):
	fh = attempt_to_open_file(fn)
	if not fh:
	return
	fh.close()
	time.sleep(0.1)
	if ignore_errors:
	return
	raise Exception('File can still be opened')

	def run_and_log(u_boot_console, cmd, ignore_errors=False, stdin=None, env=None):
	"""Run a command and log its output.

	Args:
	u_boot_console: A console connection to U-Boot.
	cmd: The command to run, as an array of argv[], or a string.
	If a string, note that it is split up so that quoted spaces
	will not be preserved. E.g. "fred and" becomes ['"fred', 'and"']
	ignore_errors: Indicate whether to ignore errors. If True, the function
	will simply return if the command cannot be executed or exits with
	an error code, otherwise an exception will be raised if such
	problems occur.
	stdin: Input string to pass to the command as stdin (or None)
	env: Environment to use, or None to use the current one

	Returns:
	The output as a string.
	"""
	if isinstance(cmd, str):
	cmd = cmd.split()
	runner = u_boot_console.log.get_runner(cmd[0], sys.stdout)
	output = runner.run(cmd, ignore_errors=ignore_errors, stdin=stdin, env=env)
	runner.close()
	return output

	def run_and_log_expect_exception(u_boot_console, cmd, retcode, msg):
	"""Run a command that is expected to fail.

	This runs a command and checks that it fails with the expected return code
	and exception method. If not, an exception is raised.

	Args:
	u_boot_console: A console connection to U-Boot.
	cmd: The command to run, as an array of argv[].
	retcode: Expected non-zero return code from the command.
	msg: String that should be contained within the command's output.
	"""
	try:
	runner = u_boot_console.log.get_runner(cmd[0], sys.stdout)
	runner.run(cmd)
	except Exception:
	assert retcode == runner.exit_status
	assert msg in runner.output
	else:
	raise Exception("Expected an exception with retcode %d message '%s',"
	"but it was not raised" % (retcode, msg))
	finally:
	runner.close()

	ram_base = None
	def find_ram_base(u_boot_console):
	"""Find the running U-Boot's RAM location.

	Probe the running U-Boot to determine the address of the first bank
	of RAM. This is useful for tests that test reading/writing RAM, or
	load/save files that aren't associated with some standard address
	typically represented in an environment variable such as
	${kernel_addr_r}. The value is cached so that it only needs to be
	actively read once.

	Args:
	u_boot_console: A console connection to U-Boot.

	Returns:
	The address of U-Boot's first RAM bank, as an integer.
	"""

	global ram_base
	if u_boot_console.config.buildconfig.get('config_cmd_bdi', 'n') != 'y':
	pytest.skip('bdinfo command not supported')
	if ram_base == -1:
	pytest.skip('Previously failed to find RAM bank start')
	if ram_base is not None:
	return ram_base

	with u_boot_console.log.section('find_ram_base'):
	response = u_boot_console.run_command('bdinfo')
	for l in response.split('\n'):
	if '-> start' in l or 'memstart =' in l:
	ram_base = int(l.split('=')[1].strip(), 16)
	break
	if ram_base is None:
	ram_base = -1
	raise Exception('Failed to find RAM bank start in `bdinfo`')

	# We don't want ram_base to be zero as some functions test if the given
	# address is NULL (0). Besides, on some RISC-V targets the low memory
	# is protected that prevents S-mode U-Boot from access.
	# Let's add 2MiB then (size of an ARM LPAE/v8 section).

	ram_base += 1024 * 1024 * 2

	return ram_base

	class PersistentFileHelperCtxMgr(object):
	"""A context manager for Python's "with" statement, which ensures that any
	generated file is deleted (and hence regenerated) if its mtime is older
	than the mtime of the Python module which generated it, and gets an mtime
	newer than the mtime of the Python module which generated after it is
	generated. Objects of this type should be created by factory function
	persistent_file_helper rather than directly."""

	def __init__(self, log, filename):
	"""Initialize a new object.

	Args:
	log: The Logfile object to log to.
	filename: The filename of the generated file.

	Returns:
	Nothing.
	"""

	self.log = log
	self.filename = filename

	def __enter__(self):
	frame = inspect.stack()[1]
	module = inspect.getmodule(frame[0])
	self.module_filename = module.__file__
	self.module_timestamp = os.path.getmtime(self.module_filename)

	if os.path.exists(self.filename):
	filename_timestamp = os.path.getmtime(self.filename)
	if filename_timestamp < self.module_timestamp:
	self.log.action('Removing stale generated file ' +
	self.filename)
	pathlib.Path(self.filename).unlink()

	def __exit__(self, extype, value, traceback):
	if extype:
	try:
	pathlib.Path(self.filename).unlink()
	except Exception:
	pass
	return
	logged = False
	for _ in range(20):
	filename_timestamp = os.path.getmtime(self.filename)
	if filename_timestamp > self.module_timestamp:
	break
	if not logged:
	self.log.action(
	'Waiting for generated file timestamp to increase')
	logged = True
	os.utime(self.filename)
	time.sleep(0.1)

	def persistent_file_helper(u_boot_log, filename):
	"""Manage the timestamps and regeneration of a persistent generated
	file. This function creates a context manager for Python's "with"
	statement

	Usage:
	with persistent_file_helper(u_boot_console.log, filename):
	code to generate the file, if it's missing.

	Args:
	u_boot_log: u_boot_console.log.
	filename: The filename of the generated file.

	Returns:
	A context manager object.
	"""

	return PersistentFileHelperCtxMgr(u_boot_log, filename)

	def crc32(u_boot_console, address, count):
	"""Helper function used to compute the CRC32 value of a section of RAM.

	Args:
	u_boot_console: A U-Boot console connection.
	address: Address where data starts.
	count: Amount of data to use for calculation.

	Returns:
	CRC32 value
	"""

	bcfg = u_boot_console.config.buildconfig
	has_cmd_crc32 = bcfg.get('config_cmd_crc32', 'n') == 'y'
	assert has_cmd_crc32, 'Cannot compute crc32 without CONFIG_CMD_CRC32.'
	output = u_boot_console.run_command('crc32 %08x %x' % (address, count))

	m = re.search('==> ([0-9a-fA-F]{8})$', output)
	assert m, 'CRC32 operation failed.'

	return m.group(1)

	def waitpid(pid, timeout=60, kill=False):
	"""Wait a process to terminate by its PID

	This is an alternative to a os.waitpid(pid, 0) call that works on
	processes that aren't children of the python process.

	Args:
	pid: PID of a running process.
	timeout: Time in seconds to wait.
	kill: Whether to forcibly kill the process after timeout.

	Returns:
	True, if the process ended on its own.
	False, if the process was killed by this function.

	Raises:
	TimeoutError, if the process is still running after timeout.
	"""
	try:
	for _ in range(timeout):
	os.kill(pid, 0)
	time.sleep(1)

	if kill:
	os.kill(pid, signal.SIGKILL)
	return False

	except ProcessLookupError:
	return True

	raise TimeoutError(
	"Process with PID {} did not terminate after {} seconds."
	.format(pid, timeout)
	)