Hi,
If it is a generic Eclipse project (not STM32CubeIDE), VisualGDB won’t be able to import it automatically. Instead, we would advise using the generic import mode of the Embedded Project Wizard to pull all the project sources into a new Visual Studio project. Then, you would need to manually transfer the build settings (list of include directories, preprocessor macros, and device-specific flags).
When importing the project, you can select “specify flags manually” on the MCU selection page (see this tutorial) and later use the first page of VisualGDB Project Properties to specify the device-specific settings. If you use Advanced CMake, you can later export the custom BSP into a reusable package and use it to create new projects easier.
With J-Link, VisualGDB caches the device list in the %LOCALAPPDATA%\VisualGDB\EmbeddedDebugPackages\com.sysprogs.arm.segger-dmsp\DeviceList.txt file. You can either delete it to have VisualGDB re-query the device list, or just patch it manually. You can also bypass it completely and edit the J-Link command line manually via the Advanced view in the VisualGDB Settings.