CMSIS-Pack

heliaRT provides a source-pack generator driven by the same source manifest as its CMake integrations. Use it with an existing CMSIS-based application when you want its project tools to manage runtime sources.

Build the pack

Use a pinned runtime checkout with Python 3 and CMake available. From its root:

python3 tools/cmsis_pack/build_pack.py --output dist --keep-stage

For runtime v1.21.2, this produces:

dist/Ambiq.helia-rt.1.21.2.pack
dist/Ambiq.helia-rt.1.21.2.stage/

The generator derives the version from the runtime source manifest. Use the filename printed by your checkout rather than assuming the example version. It includes the selected runtime sources, public headers, license and PDSC description.

Validate and install

Install CMSIS-Toolbox for packchk and cpackget, then validate the generated pack:

python3 tools/cmsis_pack/check_pdsc.py dist/Ambiq.helia-rt.1.21.2.pack
packchk --disable-validation dist/Ambiq.helia-rt.1.21.2.stage/Ambiq.helia-rt.pdsc
cpackget add --agree-embedded-license dist/Ambiq.helia-rt.1.21.2.pack

--agree-embedded-license accepts the license file shipped inside the pack, which cpackget otherwise asks about interactively. The packchk invocation matches the repository’s packaging workflow: semantic checks run with XSD validation disabled. The separate Python check verifies the pack’s expected identity and dependency contract. Neither check builds an application; the example below does.

Select a component

In your project’s component selection, use the Ambiq Machine Learning / TFLM Runtime / helia-rt component and choose one backend variant:

Variant	Dependency
Reference	Portable runtime kernels without an external NN library.
CMSIS-NN	Upstream Arm CMSIS-NN kernel dependency for your target.
HELIA	The Ambiq heliaCORE (ns-cmsis-nn) source component. The generated PDSC requires version 7.35.0 or newer.

Keep runtime and kernel feature settings consistent. A HELIA component selection does not establish support for every operator, tensor type or model shape. Review Model compatibility before enabling float kernels.

Build the example consumer

tools/cmsis_pack/examples/hello_world is a minimal CMSIS-Toolbox solution. It targets the generic ARM::ARMCM55 device and builds one project per variant: hello_world selects Reference, and hello_world_helia selects HELIA with heliaCORE built from the Ambiq::NS-CMSIS-NN source pack. Each links a MicroInterpreter against the installed packs. Add the heliaRT pack with cpackget, plus the ns-cmsis-nn pack (Ambiq.NS-CMSIS-NN.<version>.pack from the ns-cmsis-nn release that heliaRT pins, 7.35.0 or newer). Then point CMSIS-Toolbox 2.13.0 at each compiler’s bin directory with a variable named after its version, for example GCC_TOOLCHAIN_14_3_1 for Arm GNU 14.3.rel1 and CLANG_TOOLCHAIN_22_1_0 for ATfE 22.1.0. Then build:

cd tools/cmsis_pack/examples/hello_world
cbuild hello_world.csolution.yml --toolchain GCC --update-rte --packs
cbuild hello_world.csolution.yml --toolchain CLANG --update-rte --packs

--packs installs the pinned public ARM::CMSIS and ARM::Cortex_DFP packs from the public pack index on first use. The example links --specs=nosys.specs on GCC and -lsemihost on ATfE to satisfy the C library’s I/O and exit hooks; a board application supplies its own retarget layer instead. The packaging workflow builds this example on both compilers. It proves the Reference and HELIA variants compile and link together with their dependencies. It does not build the CMSIS-NN variant or run a model.

A project that selects HELIA also adds the ns-cmsis-nn pack root to its include path, as hello_world_helia.cproject.yml does with add-path: $Pack(Ambiq::NS-CMSIS-NN)$. heliaRT includes heliaCORE headers as Include/<name>.h, relative to the ns-cmsis-nn root, which the ns-cmsis-nn pack does not export (ns-cmsis-nn#657 tracks exporting the root).

Your consumer project still provides the device/board support, compiler settings, startup code, memory layout and application sources. Add the model and inference sequence from First inference, build with your CMSIS toolchain, then verify known inputs and outputs on the board.

Distribution scope

The repository workflow generates the pack as a CI artifact. This guide uses a pack built from your checkout; only the example’s Arm device packs come from the public pack index, and the ns-cmsis-nn pack comes from its GitHub release. The pack generator, contract checker and packaging workflow define its contents and checks. Board-level validation of your own project is separate from package validation.