1 # U-Boot pytest suite 2 3 ## Introduction 4 5 This tool aims to test U-Boot by executing U-Boot shell commands using the 6 console interface. A single top-level script exists to execute or attach to the 7 U-Boot console, run the entire script of tests against it, and summarize the 8 results. Advantages of this approach are: 9 10 - Testing is performed in the same way a user or script would interact with 11 U-Boot; there can be no disconnect. 12 - There is no need to write or embed test-related code into U-Boot itself. 13 It is asserted that writing test-related code in Python is simpler and more 14 flexible than writing it all in C. 15 - It is reasonably simple to interact with U-Boot in this way. 16 17 ## Requirements 18 19 The test suite is implemented using pytest. Interaction with the U-Boot console 20 involves executing some binary and interacting with its stdin/stdout. You will 21 need to implement various "hook" scripts that are called by the test suite at 22 the appropriate time. 23 24 On Debian or Debian-like distributions, the following packages are required. 25 Some packages are required to execute any test, and others only for specific 26 tests. Similar package names should exist in other distributions. 27 28 | Package | Version tested (Ubuntu 14.04) | 29 | -------------- | ----------------------------- | 30 | python | 2.7.5-5ubuntu3 | 31 | python-pytest | 2.5.1-1 | 32 | gdisk | 0.8.8-1ubuntu0.1 | 33 | dfu-util | 0.5-1 | 34 | dtc | 1.4.0+dfsg-1 | 35 | openssl | 1.0.1f-1ubuntu2.22 | 36 37 The test script supports either: 38 39 - Executing a sandbox port of U-Boot on the local machine as a sub-process, 40 and interacting with it over stdin/stdout. 41 - Executing an external "hook" scripts to flash a U-Boot binary onto a 42 physical board, attach to the board's console stream, and reset the board. 43 Further details are described later. 44 45 ### Using `virtualenv` to provide requirements 46 47 Older distributions (e.g. Ubuntu 10.04) may not provide all the required 48 packages, or may provide versions that are too old to run the test suite. One 49 can use the Python `virtualenv` script to locally install more up-to-date 50 versions of the required packages without interfering with the OS installation. 51 For example: 52 53 ```bash 54 $ cd /path/to/u-boot 55 $ sudo apt-get install python python-virtualenv 56 $ virtualenv venv 57 $ . ./venv/bin/activate 58 $ pip install pytest 59 ``` 60 61 ## Testing sandbox 62 63 To run the testsuite on the sandbox port (U-Boot built as a native user-space 64 application), simply execute: 65 66 ``` 67 ./test/py/test.py --bd sandbox --build 68 ``` 69 70 The `--bd` option tells the test suite which board type is being tested. This 71 lets the test suite know which features the board has, and hence exactly what 72 can be tested. 73 74 The `--build` option tells U-Boot to compile U-Boot. Alternatively, you may 75 omit this option and build U-Boot yourself, in whatever way you choose, before 76 running the test script. 77 78 The test script will attach to U-Boot, execute all valid tests for the board, 79 then print a summary of the test process. A complete log of the test session 80 will be written to `${build_dir}/test-log.html`. This is best viewed in a web 81 browser, but may be read directly as plain text, perhaps with the aid of the 82 `html2text` utility. 83 84 ### Testing under a debugger 85 86 If you need to run sandbox under a debugger, you may pass the command-line 87 option `--gdbserver COMM`. This causes two things to happens: 88 89 - Instead of running U-Boot directly, it will be run under gdbserver, with 90 debug communication via the channel `COMM`. You can attach a debugger to the 91 sandbox process in order to debug it. See `man gdbserver` and the example 92 below for details of valid values for `COMM`. 93 - All timeouts in tests are disabled, allowing U-Boot an arbitrary amount of 94 time to execute commands. This is useful if U-Boot is stopped at a breakpoint 95 during debugging. 96 97 A usage example is: 98 99 Window 1: 100 ```shell 101 ./test/py/test.py --bd sandbox --gdbserver localhost:1234 102 ``` 103 104 Window 2: 105 ```shell 106 gdb ./build-sandbox/u-boot -ex 'target remote localhost:1234' 107 ``` 108 109 Alternatively, you could leave off the `-ex` option and type the command 110 manually into gdb once it starts. 111 112 You can use any debugger you wish, so long as it speaks the gdb remote 113 protocol, or any graphical wrapper around gdb. 114 115 Some tests deliberately cause the sandbox process to exit, e.g. to test the 116 reset command, or sandbox's CTRL-C handling. When this happens, you will need 117 to attach the debugger to the new sandbox instance. If these tests are not 118 relevant to your debugging session, you can skip them using pytest's -k 119 command-line option; see the next section. 120 121 ## Command-line options 122 123 - `--board-type`, `--bd`, `-B` set the type of the board to be tested. For 124 example, `sandbox` or `seaboard`. 125 - `--board-identity`, `--id` set the identity of the board to be tested. 126 This allows differentiation between multiple instances of the same type of 127 physical board that are attached to the same host machine. This parameter is 128 not interpreted by the test script in any way, but rather is simply passed 129 to the hook scripts described below, and may be used in any site-specific 130 way deemed necessary. 131 - `--build` indicates that the test script should compile U-Boot itself 132 before running the tests. If using this option, make sure that any 133 environment variables required by the build process are already set, such as 134 `$CROSS_COMPILE`. 135 - `--build-dir` sets the directory containing the compiled U-Boot binaries. 136 If omitted, this is `${source_dir}/build-${board_type}`. 137 - `--result-dir` sets the directory to write results, such as log files, 138 into. If omitted, the build directory is used. 139 - `--persistent-data-dir` sets the directory used to store persistent test 140 data. This is test data that may be re-used across test runs, such as file- 141 system images. 142 143 `pytest` also implements a number of its own command-line options. Commonly used 144 options are mentioned below. Please see `pytest` documentation for complete 145 details. Execute `py.test --version` for a brief summary. Note that U-Boot's 146 test.py script passes all command-line arguments directly to `pytest` for 147 processing. 148 149 - `-k` selects which tests to run. The default is to run all known tests. This 150 option takes a single argument which is used to filter test names. Simple 151 logical operators are supported. For example: 152 - `'ums'` runs only tests with "ums" in their name. 153 - `'ut_dm'` runs only tests with "ut_dm" in their name. Note that in this 154 case, "ut_dm" is a parameter to a test rather than the test name. The full 155 test name is e.g. "test_ut[ut_dm_leak]". 156 - `'not reset'` runs everything except tests with "reset" in their name. 157 - `'ut or hush'` runs only tests with "ut" or "hush" in their name. 158 - `'not (ut or hush)'` runs everything except tests with "ut" or "hush" in 159 their name. 160 - `-s` prevents pytest from hiding a test's stdout. This allows you to see 161 U-Boot's console log in real time on pytest's stdout. 162 163 ## Testing real hardware 164 165 The tools and techniques used to interact with real hardware will vary 166 radically between different host and target systems, and the whims of the user. 167 For this reason, the test suite does not attempt to directly interact with real 168 hardware in any way. Rather, it executes a standardized set of "hook" scripts 169 via `$PATH`. These scripts implement certain actions on behalf of the test 170 suite. This keeps the test suite simple and isolated from system variances 171 unrelated to U-Boot features. 172 173 ### Hook scripts 174 175 #### Environment variables 176 177 The following environment variables are set when running hook scripts: 178 179 - `UBOOT_BOARD_TYPE` the board type being tested. 180 - `UBOOT_BOARD_IDENTITY` the board identity being tested, or `na` if none was 181 specified. 182 - `UBOOT_SOURCE_DIR` the U-Boot source directory. 183 - `UBOOT_TEST_PY_DIR` the full path to `test/py/` in the source directory. 184 - `UBOOT_BUILD_DIR` the U-Boot build directory. 185 - `UBOOT_RESULT_DIR` the test result directory. 186 - `UBOOT_PERSISTENT_DATA_DIR` the test persistent data directory. 187 188 #### `u-boot-test-console` 189 190 This script provides access to the U-Boot console. The script's stdin/stdout 191 should be connected to the board's console. This process should continue to run 192 indefinitely, until killed. The test suite will run this script in parallel 193 with all other hooks. 194 195 This script may be implemented e.g. by exec()ing `cu`, `kermit`, `conmux`, etc. 196 197 If you are able to run U-Boot under a hardware simulator such as qemu, then 198 you would likely spawn that simulator from this script. However, note that 199 `u-boot-test-reset` may be called multiple times per test script run, and must 200 cause U-Boot to start execution from scratch each time. Hopefully your 201 simulator includes a virtual reset button! If not, you can launch the 202 simulator from `u-boot-test-reset` instead, while arranging for this console 203 process to always communicate with the current simulator instance. 204 205 #### `u-boot-test-flash` 206 207 Prior to running the test suite against a board, some arrangement must be made 208 so that the board executes the particular U-Boot binary to be tested. Often, 209 this involves writing the U-Boot binary to the board's flash ROM. The test 210 suite calls this hook script for that purpose. 211 212 This script should perform the entire flashing process synchronously; the 213 script should only exit once flashing is complete, and a board reset will 214 cause the newly flashed U-Boot binary to be executed. 215 216 It is conceivable that this script will do nothing. This might be useful in 217 the following cases: 218 219 - Some other process has already written the desired U-Boot binary into the 220 board's flash prior to running the test suite. 221 - The board allows U-Boot to be downloaded directly into RAM, and executed 222 from there. Use of this feature will reduce wear on the board's flash, so 223 may be preferable if available, and if cold boot testing of U-Boot is not 224 required. If this feature is used, the `u-boot-test-reset` script should 225 perform this download, since the board could conceivably be reset multiple 226 times in a single test run. 227 228 It is up to the user to determine if those situations exist, and to code this 229 hook script appropriately. 230 231 This script will typically be implemented by calling out to some SoC- or 232 board-specific vendor flashing utility. 233 234 #### `u-boot-test-reset` 235 236 Whenever the test suite needs to reset the target board, this script is 237 executed. This is guaranteed to happen at least once, prior to executing the 238 first test function. If any test fails, the test infra-structure will execute 239 this script again to restore U-Boot to an operational state before running the 240 next test function. 241 242 This script will likely be implemented by communicating with some form of 243 relay or electronic switch attached to the board's reset signal. 244 245 The semantics of this script require that when it is executed, U-Boot will 246 start running from scratch. If the U-Boot binary to be tested has been written 247 to flash, pulsing the board's reset signal is likely all this script need do. 248 However, in some scenarios, this script may perform other actions. For 249 example, it may call out to some SoC- or board-specific vendor utility in order 250 to download the U-Boot binary directly into RAM and execute it. This would 251 avoid the need for `u-boot-test-flash` to actually write U-Boot to flash, thus 252 saving wear on the flash chip(s). 253 254 #### Examples 255 256 https://github.com/swarren/uboot-test-hooks contains some working example hook 257 scripts, and may be useful as a reference when implementing hook scripts for 258 your platform. These scripts are not considered part of U-Boot itself. 259 260 ### Board-type-specific configuration 261 262 Each board has a different configuration and behaviour. Many of these 263 differences can be automatically detected by parsing the `.config` file in the 264 build directory. However, some differences can't yet be handled automatically. 265 266 For each board, an optional Python module `u_boot_board_${board_type}` may exist 267 to provide board-specific information to the test script. Any global value 268 defined in these modules is available for use by any test function. The data 269 contained in these scripts must be purely derived from U-Boot source code. 270 Hence, these configuration files are part of the U-Boot source tree too. 271 272 ### Execution environment configuration 273 274 Each user's hardware setup may enable testing different subsets of the features 275 implemented by a particular board's configuration of U-Boot. For example, a 276 U-Boot configuration may support USB device mode and USB Mass Storage, but this 277 can only be tested if a USB cable is connected between the board and the host 278 machine running the test script. 279 280 For each board, optional Python modules `u_boot_boardenv_${board_type}` and 281 `u_boot_boardenv_${board_type}_${board_identity}` may exist to provide 282 board-specific and board-identity-specific information to the test script. Any 283 global value defined in these modules is available for use by any test 284 function. The data contained in these is specific to a particular user's 285 hardware configuration. Hence, these configuration files are not part of the 286 U-Boot source tree, and should be installed outside of the source tree. Users 287 should set `$PYTHONPATH` prior to running the test script to allow these 288 modules to be loaded. 289 290 ### Board module parameter usage 291 292 The test scripts rely on the following variables being defined by the board 293 module: 294 295 - None at present. 296 297 ### U-Boot `.config` feature usage 298 299 The test scripts rely on various U-Boot `.config` features, either directly in 300 order to test those features, or indirectly in order to query information from 301 the running U-Boot instance in order to test other features. 302 303 One example is that testing of the `md` command requires knowledge of a RAM 304 address to use for the test. This data is parsed from the output of the 305 `bdinfo` command, and hence relies on CONFIG_CMD_BDI being enabled. 306 307 For a complete list of dependencies, please search the test scripts for 308 instances of: 309 310 - `buildconfig.get(...` 311 - `@pytest.mark.buildconfigspec(...` 312 313 ### Complete invocation example 314 315 Assuming that you have installed the hook scripts into $HOME/ubtest/bin, and 316 any required environment configuration Python modules into $HOME/ubtest/py, 317 then you would likely invoke the test script as follows: 318 319 If U-Boot has already been built: 320 321 ```bash 322 PATH=$HOME/ubtest/bin:$PATH \ 323 PYTHONPATH=${HOME}/ubtest/py/${HOSTNAME}:${PYTHONPATH} \ 324 ./test/py/test.py --bd seaboard 325 ``` 326 327 If you want the test script to compile U-Boot for you too, then you likely 328 need to set `$CROSS_COMPILE` to allow this, and invoke the test script as 329 follow: 330 331 ```bash 332 CROSS_COMPILE=arm-none-eabi- \ 333 PATH=$HOME/ubtest/bin:$PATH \ 334 PYTHONPATH=${HOME}/ubtest/py/${HOSTNAME}:${PYTHONPATH} \ 335 ./test/py/test.py --bd seaboard --build 336 ``` 337 338 ## Writing tests 339 340 Please refer to the pytest documentation for details of writing pytest tests. 341 Details specific to the U-Boot test suite are described below. 342 343 A test fixture named `u_boot_console` should be used by each test function. This 344 provides the means to interact with the U-Boot console, and retrieve board and 345 environment configuration information. 346 347 The function `u_boot_console.run_command()` executes a shell command on the 348 U-Boot console, and returns all output from that command. This allows 349 validation or interpretation of the command output. This function validates 350 that certain strings are not seen on the U-Boot console. These include shell 351 error messages and the U-Boot sign-on message (in order to detect unexpected 352 board resets). See the source of `u_boot_console_base.py` for a complete list of 353 "bad" strings. Some test scenarios are expected to trigger these strings. Use 354 `u_boot_console.disable_check()` to temporarily disable checking for specific 355 strings. See `test_unknown_cmd.py` for an example. 356 357 Board- and board-environment configuration values may be accessed as sub-fields 358 of the `u_boot_console.config` object, for example 359 `u_boot_console.config.ram_base`. 360 361 Build configuration values (from `.config`) may be accessed via the dictionary 362 `u_boot_console.config.buildconfig`, with keys equal to the Kconfig variable 363 names. 364
