vscode-skelly-stm32

VSCode STM32 skelleton base example project to work (develop and debug) with STM32 microcontrollers on a Linux system without the need of a full IDE.

This project example target a Nucleo-F401RE board, but the repository can be used as a reference to create new projects for other targets.

Requirements

Install required libraries:

sudo apt-get update
sudo apt-get -y install libncurses5 libncurses5-dev libncursesw5-dev
sudo apt-get -y install libc6 libc6-dev
sudo apt-get -y install libudev libudev-dev

Install the ARM Toolchain:

cd /opt
sudo wget https://developer.arm.com/-/media/Files/downloads/gnu-rm/10.3-2021.07/gcc-arm-none-eabi-10.3-2021.07-x86_64-linux.tar.bz2
sudo tar -xf gcc-arm-none-eabi-10.3-2021.07-x86_64-linux.tar.bz2
sudo rm -f gcc-arm-none-eabi-10.3-2021.07-x86_64-linux.tar.bz2
sudo ln -sf /opt/gcc-arm-none-eabi-10.3-2021.07/bin/* /usr/bin/

Install Debugging Tools:

sudo apt-get -y install openocd
sudo apt-get -y install stlink-tools

In vscode, install C/C++ and Cortex-Debug extensions.

How to Create a STM32 project supported by vscode

Here is the steps that has been followed to create current project:

Use STM32CubeMX software to create a STM32 base project for a specific target, and generate it as a "Makefile project".
Open the generated project directory inside vscode.
Create a ./vscode/settings.json file and setup specific Toolchain and tools path in there.
Create a ./vscode/c_cpp_properties.json file and setup C & C++ standard versions, the arm-none-eabi-gcc compiler path, Defines and the compiler arguments that are used in project Makefile to setup correctly intellisense functionality.
Create a ./vscode/tasks.json file and setup Make build commands, and tasks available, to be used from vscode.
Create a ./vscode/launch.json file and setup each available debuggers to be used and their specific configurations for target device.

Adding Segger RTT debug interface support

To get the Segger Real Time Transfer (RTT) debugging mechanism to send and receive messages (or any data) through a JLINK debugger:

Get and install the Segger RTT API by downloading the JLink Software Pack, and extract the API from /opt/SEGGER/JLink/Samples/RTT/* into project Drivers/ directory. You can also get the API files from this GIT repository, however it won't receive updates from Segger.
Modify the project Makefile to point to the new headers and sources of the RTT API.
Include the RTT main header on a file where you want to have access to it, and start using the RTT functionality.

Usage

Build and Debug:

Physically connect the hardware programmer to target device and the PC.
Open main.c file.
Go to Run and Debug left panel menu and select some launch configuration according to programmer and debugger that will be used (stlink, jlink, openocd...).
Press Run button.

Release Flash:

Press Ctrl+Shift+B to show the configured Tasks of the project.
Execute one of the Task to flash the firmware into the device through any of the supported and configured interfaces (STFlash for stlink, JFlash for jklink, **UARTFlash for UART interface).

Notes

Remember that compiler optimizations will translate the C/C++ code to an efficient memory/speed ASM, causing that lines execution behavior when debugging will confuse a human. To keep a sequentially line-by-line execution a -Og flag/parameter needs to be passed to the compiler (change that in Makefile). Of course, you won't want this debug oriented optimization for Release, so you should use -Os for firmware Release.
There is a good video resource where I have based this project setup from.
Some resources regarding Segger RTT debugging:

https://www.segger.com/products/debug-probes/j-link/technology/about-real-time-transfer/

https://www.codeinsideout.com/blog/stm32/j-link-rtt/