Ceedling is a build automation tool that helps you create and run C unit test suites. Ceedling provides two core functions: [1] It packages up several tools including the C unit test framework Unity, the mock generation tool CMock, and other features. [2] It simplifies tool configuration for embedded or native C toolchains and automates the running and reporting of tests. Ceedling projects are created with a YAML configuration file. A variety of conventions within the tool simplify generating mocks from C files and assembling suites of unit test functions.