libdisplay-info/README.md
Simon Ser 147d6611a6 readme: update test suite instructions
Since eed3e1e0f8 ("test: remove edid-decode as a test
dependency"), edid-decode is no longer required to run the test
suite. It's only required to re-generate the test data.

Expand a bit on how to setup edid-decode to re-generate the test
data.

Signed-off-by: Simon Ser <contact@emersion.fr>
2023-03-02 19:43:44 +01:00

3.1 KiB

libdisplay-info

EDID and DisplayID library.

Goals:

  • Provide a set of high-level, easy-to-use, opinionated functions as well as low-level functions to access detailed information.
  • Simplicity and correctness over performance and resource usage.
  • Well-tested and fuzzed.

Documentation is available on the website.

Using

The public API headers are categorised as either high-level or low-level API as per the comments in the header files. Users of libdisplay-info should prefer high-level API over low-level API when possible.

If high-level API lacks needed features, please propose additions to the high-level API upstream before using low-level API to get what you need. If the additions are rejected, you are welcome to use the low-level API.

This policy is aimed to propagate best practises when interpreting EDID and DisplayID information which can often be cryptic or even inconsistent.

libdisplay-info uses semantic versioning. The public API is not yet stable.

Contributing

Open issues and merge requests on the GitLab project. Discuss and ask questions in the #wayland IRC channel on OFTC.

In general, the Wayland contribution guidelines should be followed. In particular, each commit must carry a Signed-off-by tag to denote that the submitter adheres to the Developer Certificate of Origin 1.1. This project follows the freedesktop.org Contributor Covenant.

Building

libdisplay-info has the following dependencies:

  • hwdata for the PNP ID database used at build-time only.

libdisplay-info is built using Meson:

meson setup build/
ninja -C build/

Testing

The low-level EDID library is tested against edid-decode. test/data/ contains a small collection of EDID blobs and diffs between upstream edid-decode and our di-edid-decode clone. Our CI ensures the diffs are up-to-date. A patch should never make the diffs grow larger. To re-generate the test data, build edid-decode at the Git revision mentioned in .gitlab-ci.yml, put the executable in PATH, and run ninja -C build/ gen-test-data.

The latest code coverage report is available on GitLab CI.

Fuzzing

To fuzz libdisplay-info with AFL, the library needs to be instrumented:

CC=afl-gcc meson build/
ninja -C build/
afl-fuzz -i test/data/ -o afl/ build/di-edid-decode/di-edid-decode