ra8_npu.c File Reference

Arm Ethos-U55 NPU command/queue driver foundation (RA8P1-only). More...

#include "ra8_attributes.h"
#include "ra8_device.h"

Include dependency graph for ra8_npu.c:

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Typedefs
typedef int	ra8_npu_not_on_this_device_t

Detailed Description

Arm Ethos-U55 NPU command/queue driver foundation (RA8P1-only).

Tag

[Ring 3 / HAL] {World: S}

Implementation of the ra8_npu.h contract. The whole translation unit is gated behind RA8_HAS_NPU so it compiles to nothing on the RA8D2 (which has no NPU) and is only built for the RA8P1 (-DRA8_DEVICE_RA8P1). Every MMIO access carries an Arm Ethos-U55 NPU TRM citation; the RA8P1 integration facts (module-stop bit, clock, IRQ) are sourced in ra8_npu_regs.h.

The command-stream model implemented here is the Ethos-U55 submission protocol: program QBASE/QSIZE at the Vela command stream, program each BASEPn tensor-arena base, then write CMD.transition_to_running_state to run; completion and faults are read from STATUS. There is no RA8P1 board yet, so this is host-tested for the register write sequence only – a real on-silicon inference is a follow-up.

Copyright

Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since

0.1.0

Definition in file ra8_npu.c.

Typedef Documentation

ra8_npu_not_on_this_device_t

typedef int ra8_npu_not_on_this_device_t

Definition at line 450 of file ra8_npu.c.