Added optional support for mbedTLS that can be taken by passing arguments
Fixes issue: #18319

Summary

• MicroPython’s UNIX port by default uses a bundled lib/mbedtls submodule.

• This causes issues if the submodule is missing or you prefer the system-installed MbedTLS.

• MICROPY_USE_SYSTEM_MBEDTLS=1 tells the Makefile to use the system-installed MbedTLS

Benefits:

No need for lib/mbedtls submodule.

Uses system-managed MbedTLS version.

Optional: can revert to bundled submodule by not setting the flag.

Portable: works on different Linux systems if pkg-config is available.

Testing

Need to export the value before :

Signals to the ports/unix/Makefile that you want to link against the system-installed MbedTLS rather than the bundled lib/mbedtls submodule.

It’s a clean way to make the build optional — you can turn it off just by not exporting it.

Why it’s needed:

• MicroPython’s UNIX port by default expects the bundled lib/mbedtls.

• If you want to avoid downloading or maintaining the submodule, this variable instructs the Makefile to skip it.

Trade-offs and Alternatives

• You could also hardcode the use of system MbedTLS in the Makefile by directly editing it, but that makes the build less flexible for others who might want the bundled version.

Note:
Ensure you have the necessary packages: