Model-based testing (MBT) has been previously used to validate embedded systems. However, (i) creation of a model conforming to the behavioural aspects of an embedded system, (ii) generation of executable test scripts and (iii) assessment of test verdict, re-quires a systematic process. In this paper, we have presented a three-phase tool-supported MBT workflow for the testing of an embedded system, that spans from requirements specification to test verdict assessment. The workflow starts with a simplistic, yet practical, application of a Domain-Specific Language (DSL) based on Gherkin-like style, which allows the requirements engineer to specify requirements and to extract information about model elements(i.e. states and transitions). This is done to assist the graphical modelling of the complete system under test (SUT). Later stages of the workflow generates an executable test script that runs on a domain-specific simulation platform. We have evaluated this tool-supported workflow by specifying the requirements, extracting information from the DSL and developing a model of a subsystem of the train control management system developed at Alstom Transport AB in Sweden. The C# test script generated from the SUT model is successfully executed at the Software-in-the-Loop (SIL) execution platform and test verdicts are visualized as a sequence of passed and failed test steps.