--- title: "Tests and coverage on the board" --- # Tests and coverage on the board The image's runtime tests in the Testing view, run with bitbake -c testimage against a board or QEMU, ptest-runner on a board, results compared with resulttool, and structural coverage of tests run on the board with gcov. ## Runtime tests and ptest **State:** modelled: all 120 runtime test ids of poky's `meta` layer equal to OEQA's own loader; a real `bitbake -c testimage` started from the module (BitBake 2.8.1, poky scarthgap 5.0.21, meta-freescale, imx8mp-lpddr4-evk) against a BusyBox stand-in board over OpenSSH, with `testdata.json` written by OE-Core; resulttool comparing two real runs; real `run-ptest` output read per test. **No image was built**, testimage on QEMU (`TEST_TARGET = "qemu"`) was not run, and `ptest-runner` itself was not run. Not run on a real board, on Windows, against a real build server or on Wind River Linux. On the build host, add `IMAGE_CLASSES += "testimage"` and build the image so its test data is written; for ptest, add `ptest-runner` and the `ptest` distro feature to the image. 1. Run **Select Runtime Test Image** and **Select Runtime Test Target** (a board of the Targets view, or QEMU). 2. The **Testing** view lists the image's runtime tests (**Embedded Linux Runtime Tests**), read from TEST_SUITES and each layer's `lib/oeqa/runtime/cases` when you expand the image. Clicking a test opens its case at the line that declares it. 3. **Run testimage** runs `bitbake -c testimage` after a confirmation that shows TEST_TARGET (`simpleremote` for a board), TEST_TARGET_IP, TEST_SERVER_IP and the command. Only those settings and TEST_SUITES are passed; no build directory changes, though the first run with new settings reparses every recipe into a second parse cache. 4. `testresults.json` is read back; each failure appears at its line. 5. **Run ptests on Target** runs `ptest-runner` on a board over SSH after a confirmation; results are read per package and per test, with each package's log (**Open ptest-runner Log**). 6. **Open Runtime Test Results** opens a `testresults.json`; **Compare Runtime Test Results** compares two runs with `resulttool report` and `regression`, with the module's own comparison by resulttool's rules where poky 5.0's resulttool stops with an error. Agent tools: five read-only, two that ask first. ## Structural coverage on the board **State:** modelled with GCC 13.3 and 14.2 with gcov, gcovr 8.6 and lcov 2.0 on a C and C++ library with tests run on a stand-in BusyBox board over OpenSSH: all three engines agree, and the totals equal gcovr's own Cobertura; a real stamp mismatch set aside; condition outcomes equal to gcov's summary; an aarch64 cross GCC 13.3 on a QEMU arm64 board with Dropbear; the running app from build to gutters. The kernel path was modelled on a folder in gcov-kernel's layout; no kernel with `CONFIG_GCOV_KERNEL` was booted. Not run with a real Yocto, Wind River or vendor SDK, with devtool and BitBake, on Windows, against a real build server or at realistic size. Coverage here is not qualified MC/DC. 1. Install gcovr or lcov on the build host, or list their folders in `neuralInverse.embeddedLinux.coverage.toolFolders`. 2. **Build Application with Coverage...** adds `--coverage -fprofile-update=atomic`, plus `-fcondition-coverage` when the SDK's GCC is 14 or later (said plainly when it is not), and builds through the SDK into a `-coverage` build folder, after a confirmation with the exact flags. **Set or Remove Coverage Flags of a devtool Recipe...** writes the same flags into the devtool workspace's bbappend instead. 3. **Run Tests with Coverage on Target...** copies the program, runs a command or `ptest: ` with GCOV_PREFIX and GCOV_PREFIX_STRIP, packs the counters, copies them to the build host with their SHA-256 and removes them from the board. **Stop Coverage Run** stops it. 4. Each counter file is paired with the build's notes by gcov version and stamp; mismatches are named and left out. 5. The report is read with the SDK's cross gcov through gcovr, lcov or gcov alone. **Open Coverage Report...** opens the **Structural Coverage** editor: the build and board identity, what gcov does not measure (decision coverage and MC/DC), and per file and function the lines, branch edges, GCC condition outcomes and calls. 6. The working copy gets line, branch and condition gutters with hovers. 7. **Export Coverage for the Safety Record** writes Cobertura XML, an HTML summary and a JSON record with tool versions and build identity. ![A coverage hover in the source: how often a line ran, the branch edges taken and the GCC condition outcomes covered.](https://neuralinverse.com/docs-images/modules/embedded-linux/linux-coverage-gutter-hover.webp) **Collect Kernel Coverage on Target...** reads gcov-kernel's debugfs tree for a driver folder after a test command. Agent tools: four read-only; building, writing recipe flags, running and collecting ask first. Next: [Profiling and memory checking](https://neuralinverse.com/docs/modules/embedded-linux/profiling/).