Hello, Codespaces

This repository contains an application that prints "Hello, Codespaces!" and a counter value via semihosting output on an Arm FVP simulation model (Cortex-M3).

A codespace is a development environment that's hosted in the cloud. Each codespace you create is hosted by GitHub in a Docker container, running on a virtual machine. Regardless of your local operating system, your codespace will run in a Linux environment. You can connect to your codespaces from your browser, from Visual Studio Code, or by using GitHub CLI.

Quick Start

1. Click on Use this Template (in the top right corner) and select Create a new Repository.
2. Enter a name for the new repository and click on Create repository. The new repository opens in your browser.
3. Click on the drop down next to <> Code and select Codespaces.
4. Click on Create codespace on main.

Note

The first time you create the Codespace will take a while as it installs the tools as described in the devcontainer.json file.

During the process, you will see a pop up like this:

Click on Allow For Current Workspace. This will install the tools specified in the vcpkg-configuration.json file automatically into your codespace.

When the installation finishes, you will see a pop up in the bottom right corner:

Click on Manage Arm license to select from the available options. For evaluation purposes, you can use the Arm Keil MDK-Community edition:

Note

If you missed the pop up, you can activate a license by clicking on the notification in the status bar.

Build and Run

The project is configured for execution on an Arm Cortex-M3 FVP. Using a model removes the requirement for a physical hardware board. This enables software testing directly on GitHub repositories.

1. Open the CMSIS view.
2. If the current target set context avh in the status bar shows a red background, click on the three dots and select Refresh (reload packs, update RTE). This will trigger a project update with the arm tool license you have added previously.
3. Click on Build solution to start the build process. The build should finish without errors or warnings.
4. Click on Load & Run application to run the image on the simulation model. The Terminal shows the output:

 *  Executing task: FVP_MPS2_Cortex-M3 -f fvp-config.txt --simlimit 120 -a out/hello/avh/debug/hello.axf  

Info: FVP_MPS2_Cortex_M3: telnetterminal0: Listening for serial connection on port 5000
Info: FVP_MPS2_Cortex_M3: telnetterminal1: Listening for serial connection on port 5001
Info: FVP_MPS2_Cortex_M3: telnetterminal2: Listening for serial connection on port 5002
Hello, Codespaces! 0
Hello, Codespaces! 1
Hello, Codespaces! 2
Hello, Codespaces! 3
Hello, Codespaces! 4
Hello, Codespaces! 5
Hello, Codespaces! 6
Hello, Codespaces! 7
Hello, Codespaces! 8
Hello, Codespaces! 9
Hello, Codespaces! 10
Hello, Codespaces! 11
...

Info: Simulation is stopping. Reason: Simulated time has been exceeded.
Info: /OSCI/SystemC: Simulation stopped by user.

Note

The simulation stops automatically after 120 seconds runtime.

Repository Structure

  📦
  ┣ 📂 .devcontainer                    Development container control files
     ┗ 📄 devcontainer.json              Installs the required VS Code extensions (Keil Studio Pack)
  ┣ 📂 .vscode                          VS Code specific settings files
     ┗ 📄 tasks.json                     Load & run commands to start the Arm FVP model
  ┣ 📂 hello                            Project files
     ┣ 📂 RTE                            Run-time environment related files
     ┣ 📄 hello.cproject.yml             Project file in CMSIS solution format
     ┗ 📄 main.c                         C code
  ┣ 📂 images                           Images for this README.md file
  ┣ 📄 .gitignore                       List of files not to be committed to Git
  ┣ 📄 fvp-config.txt                   Arm FVP configuration file 
  ┣ 📄 hello_codespaces.csolution.yml   CMSIS Solution file 
  ┣ 📄 LICENSE                          Apache 2.0 license file
  ┣ 📄 README.md                        This file
  ┗ 📄 vcpkg-configuration.json         Tools configuration file