ethosu_operator
Classes
EthosUOperator(op: AirOperator, model: AirModel, platform: SocPlatform, prefix: str = 'aot', attributes: dict[str, str] = {})
AIR Ethos-U custom operator.
The generated kernel drives the Arm Ethos-U NPU through the Ethos-U core
driver (ethosu_driver.h / ethosu_invoke_v3), which is a hard
dependency. The emitted source is fail-closed: if the driver header is not
on the include path the translation unit stops with a #error rather
than silently compiling a no-op stub. A non-functional stub remains
available for host-side / bring-up builds by defining
HELIA_ETHOSU_ALLOW_STUB=1 (the NPU is not executed in that mode). The
generated CMake module advertises and wires the driver dependency; see
aot/templates/cmake/CMakeLists.txt.j2.
Tensor alignment: :meth:on_resolve stamps alignment_hint = 16 on the
command stream, Vela-added auxiliary tensors, and this operator's inputs and
outputs, so the memory planner places every NPU-visible buffer on the
16-byte boundary the Ethos-U requires.
Platform gating: :meth:validate rejects conversion when the target
platform does not declare :attr:SocCapability.NPU, so scheduling this
operator onto an accelerator-less platform fails at convert time with an
actionable message instead of later in the integrator's build (#265).
Simulator targets whose NPU is provided externally (e.g. Corstone FVP)
can opt out via the require_platform_npu: "false" operator attribute,
which is reachable only through the operators: attribute ruleset in a
config YAML -- the --operators CLI flag rejects inline values because
:class:~helia_aot.attributes.defines.AttributeRuleset is a nested model.