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