Manufacturer Test Hooks - OTTF Feature


The OpenTitan Test Framework (OTTF) defines both pre- and post-test hook functions (see the prototypes below) that are invoked before and after (respectively) a test runs. By default, these hook functions do nothing. However, they provide a mechanism for manufacturers to develop closed-source test initialization / cleanup code that can be used with open-source tests.

bool manufacturer_pre_test_hook(void);
bool manufacturer_post_test_hook(void);

This feature is implemented with the help of some custom Bazel repository rules. Specifically, in sw/device/test/closed_source we define a secondary Bazel repository (@manufacturer_test_hooks) that is designed to be used in conjunction with the main OpenTitan Bazel repository. Within this repository, we define a single test_hooks library that is linked with the OTTF. The test_hooks library itself just contains default weak symbols for each test hook function. However, the test_hooks library is linked with other libraries based on a Bazel config_setting that allows you to toggle which test hook library should be override the defaults. However, the Bazel config_settings and example manufacturer test hooks library (test_hooks_1) provided in this repository are merely examples, as the test hook functions implemented do nothing, except print a message and return true;.

To learn how to use the example default and non-default test hooks with existing (open-source) tests, see the sw/default/tests/closed_source/BUILD.bazel file.

Implementing your own Test Hooks

If you are a manufacturer, and would like to implement custom test hooks (that replace the defaults) you may do so by:

  1. copying the sw/device/tests/closed_source/ directory to another location on your system,
  2. follow the steps (labeled TH-Step *) in the sw/default/tests/closed_source/BUILD.bazel file to add additional test hook libraries / config settings,
  3. invoking bazel with the MANUFACTURER_HOOKS_DIR environment variable set, and the proper config_setting , e.g., MANUFACTURER_HOOKS_DIR=</path/to/test_hooks/> bazel test //sw/device/tests:<target> --define test_hooks=<test hooks setting>

Note, with the above configuration you may place several test hook libraries in the same MANUFACTURER_HOOKS_DIR.

Implementing your own Tests

If you are a manufacturer, and would like to implement custom (closed-source) tests, you may do so by following the single step (labeled OTFT-Step 1) in the sw/default/tests/closed_source/BUILD.bazel file.