Skip to content
Snippets Groups Projects
u_boot_utils.py 7.28 KiB
Newer Older
  • Learn to ignore specific revisions
  • # Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
    #
    # SPDX-License-Identifier: GPL-2.0
    
    # Utility code shared across multiple tests.
    
    import hashlib
    import os
    import os.path
    
    import sys
    import time
    
    
    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(object):
    
        """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 xrange(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 i in xrange(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):
    
        """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.
    
        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)
    
        runner.close()
    
    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 as e:
    
            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))
    
    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`')
    
        return ram_base