Per IEC 61508-3 Section 7.4.2.12 and DO-178C Section 12.1.4, this document records the qualification basis for the Arm Ethos-U Vela compiler. Vela is a host-side build tool, not firmware SOUP: no Vela code is linked into the firmware image. It is recorded here because it goes through the same vendor process as the runtime components (owner requirement) and because the model command streams it emits are a build input to the shipped firmware.

Component identity

Name: Arm Ethos-U Vela
Version: pinned ethos-u-vela==5.1.0 (the vela dependency group in pyproject.toml, resolved by uv.lock).
Upstream URL: https://gitlab.arm.com/artificial-intelligence/ethos-u/ethos-u-vela (PyPI: https://pypi.org/project/ethos-u-vela/)
Local path: not vendored as source. Pinned as a documented build dependency in the vela group in pyproject.toml, resolved by uv.lock; usage notes in tools/vela/README.md.

Provenance

Origin: Arm Limited (Ethos-U project).
License: Apache-2.0.
How it is consumed: installed on the developer / CI host into a throwaway uv-managed environment from committed pyproject.toml and uv.lock; run offline at build time. It is never cross-compiled or linked into the RA8P1 image.

Use case in this firmware

Offline compilation of a quantized .tflite model into an Ethos-U55-optimized .tflite: NPU-supported operators are fused into a single ethos-u custom operator wrapping a Vela command stream; unsupported operators remain as CPU kernels for the on-device runtime.
The _vela.tflite output is baked into a Phase-2 examples/ra8p1_foundation application and executed by the vendored TFLite-micro MicroInterpreter. The ethos-u operator dispatches the command stream to the NPU via the first-party ra8_npu driver (see docs/SOUP/tflite-micro.md, "Phase 2").

Qualification basis

Vendor tool: Vela is Arm's own reference compiler for the Ethos-U NPU family; the command-stream format it emits is the contract the on-device Ethos-U operator implements. Compiler and runtime are version-matched by construction.
Build-time only: a defect in Vela cannot corrupt firmware at runtime; it can only produce an incorrect model artifact, which is caught by end-to-end model output verification (Phase 2 test).
Reproducibility: pinned to an exact version so command-stream output is deterministic across hosts.

Risk mitigation

Runs in an isolated virtualenv on the host; not part of the firmware trust boundary.
Its output (_vela.tflite) is validated by comparing on-device inference results against a golden reference before a model is accepted (Phase 2).

Deviations / patches

None. Consumed as the unmodified upstream PyPI release.

Last review date

Reviewed: 2026-07-10
Expected re-review by: 2027-07-10