1. Create a new project according to MbedCE instructions
2. Add this as submodule to your project via git submodule add --depth 1 https://github.com/mbed-ce-libraries-examples/custom_targets custom_targets
3. The top level CMakeList.txt (in root of your project) should be modified according to this wiki page

• if you want add a custom target that can be handy for anyone or a target that exist on public market (like BluePhill) make PR.
• For personal non-public targets make fork and create it in your own repository.
• When memory banks will be necesaeery for a new target then be sure the device-name is not present in custom_target.json5 for that target. Run python -m mbed_tools.cli.main cmsis-mcu-descr fetch-missing from path /mbed-os/tools/python and fill memory section into custom_target.json5 under memory_banks section.

• We are unable to test all targets because we simply don't have them.

Feel free to contact us for any help.