1# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. 2# 3# SPDX-License-Identifier: GPL-2.0 4 5# Utility code shared across multiple tests. 6 7import hashlib 8import os 9import os.path 10import pytest 11import sys 12import time 13import pytest 14 15def md5sum_data(data): 16 """Calculate the MD5 hash of some data. 17 18 Args: 19 data: The data to hash. 20 21 Returns: 22 The hash of the data, as a binary string. 23 """ 24 25 h = hashlib.md5() 26 h.update(data) 27 return h.digest() 28 29def md5sum_file(fn, max_length=None): 30 """Calculate the MD5 hash of the contents of a file. 31 32 Args: 33 fn: The filename of the file to hash. 34 max_length: The number of bytes to hash. If the file has more 35 bytes than this, they will be ignored. If None or omitted, the 36 entire file will be hashed. 37 38 Returns: 39 The hash of the file content, as a binary string. 40 """ 41 42 with open(fn, 'rb') as fh: 43 if max_length: 44 params = [max_length] 45 else: 46 params = [] 47 data = fh.read(*params) 48 return md5sum_data(data) 49 50class PersistentRandomFile(object): 51 """Generate and store information about a persistent file containing 52 random data.""" 53 54 def __init__(self, u_boot_console, fn, size): 55 """Create or process the persistent file. 56 57 If the file does not exist, it is generated. 58 59 If the file does exist, its content is hashed for later comparison. 60 61 These files are always located in the "persistent data directory" of 62 the current test run. 63 64 Args: 65 u_boot_console: A console connection to U-Boot. 66 fn: The filename (without path) to create. 67 size: The desired size of the file in bytes. 68 69 Returns: 70 Nothing. 71 """ 72 73 self.fn = fn 74 75 self.abs_fn = u_boot_console.config.persistent_data_dir + '/' + fn 76 77 if os.path.exists(self.abs_fn): 78 u_boot_console.log.action('Persistent data file ' + self.abs_fn + 79 ' already exists') 80 self.content_hash = md5sum_file(self.abs_fn) 81 else: 82 u_boot_console.log.action('Generating ' + self.abs_fn + 83 ' (random, persistent, %d bytes)' % size) 84 data = os.urandom(size) 85 with open(self.abs_fn, 'wb') as fh: 86 fh.write(data) 87 self.content_hash = md5sum_data(data) 88 89def attempt_to_open_file(fn): 90 """Attempt to open a file, without throwing exceptions. 91 92 Any errors (exceptions) that occur during the attempt to open the file 93 are ignored. This is useful in order to test whether a file (in 94 particular, a device node) exists and can be successfully opened, in order 95 to poll for e.g. USB enumeration completion. 96 97 Args: 98 fn: The filename to attempt to open. 99 100 Returns: 101 An open file handle to the file, or None if the file could not be 102 opened. 103 """ 104 105 try: 106 return open(fn, 'rb') 107 except: 108 return None 109 110def wait_until_open_succeeds(fn): 111 """Poll until a file can be opened, or a timeout occurs. 112 113 Continually attempt to open a file, and return when this succeeds, or 114 raise an exception after a timeout. 115 116 Args: 117 fn: The filename to attempt to open. 118 119 Returns: 120 An open file handle to the file. 121 """ 122 123 for i in xrange(100): 124 fh = attempt_to_open_file(fn) 125 if fh: 126 return fh 127 time.sleep(0.1) 128 raise Exception('File could not be opened') 129 130def wait_until_file_open_fails(fn, ignore_errors): 131 """Poll until a file cannot be opened, or a timeout occurs. 132 133 Continually attempt to open a file, and return when this fails, or 134 raise an exception after a timeout. 135 136 Args: 137 fn: The filename to attempt to open. 138 ignore_errors: Indicate whether to ignore timeout errors. If True, the 139 function will simply return if a timeout occurs, otherwise an 140 exception will be raised. 141 142 Returns: 143 Nothing. 144 """ 145 146 for i in xrange(100): 147 fh = attempt_to_open_file(fn) 148 if not fh: 149 return 150 fh.close() 151 time.sleep(0.1) 152 if ignore_errors: 153 return 154 raise Exception('File can still be opened') 155 156def run_and_log(u_boot_console, cmd, ignore_errors=False): 157 """Run a command and log its output. 158 159 Args: 160 u_boot_console: A console connection to U-Boot. 161 cmd: The command to run, as an array of argv[]. 162 ignore_errors: Indicate whether to ignore errors. If True, the function 163 will simply return if the command cannot be executed or exits with 164 an error code, otherwise an exception will be raised if such 165 problems occur. 166 167 Returns: 168 The output as a string. 169 """ 170 171 runner = u_boot_console.log.get_runner(cmd[0], sys.stdout) 172 output = runner.run(cmd, ignore_errors=ignore_errors) 173 runner.close() 174 return output 175 176ram_base = None 177def find_ram_base(u_boot_console): 178 """Find the running U-Boot's RAM location. 179 180 Probe the running U-Boot to determine the address of the first bank 181 of RAM. This is useful for tests that test reading/writing RAM, or 182 load/save files that aren't associated with some standard address 183 typically represented in an environment variable such as 184 ${kernel_addr_r}. The value is cached so that it only needs to be 185 actively read once. 186 187 Args: 188 u_boot_console: A console connection to U-Boot. 189 190 Returns: 191 The address of U-Boot's first RAM bank, as an integer. 192 """ 193 194 global ram_base 195 if u_boot_console.config.buildconfig.get('config_cmd_bdi', 'n') != 'y': 196 pytest.skip('bdinfo command not supported') 197 if ram_base == -1: 198 pytest.skip('Previously failed to find RAM bank start') 199 if ram_base is not None: 200 return ram_base 201 202 with u_boot_console.log.section('find_ram_base'): 203 response = u_boot_console.run_command('bdinfo') 204 for l in response.split('\n'): 205 if '-> start' in l or 'memstart =' in l: 206 ram_base = int(l.split('=')[1].strip(), 16) 207 break 208 if ram_base is None: 209 ram_base = -1 210 raise Exception('Failed to find RAM bank start in `bdinfo`') 211 212 return ram_base 213