Ethos-u Linux driver stack

Clone this repo:
  1. 2c01713 Add nullptr checks by Jonny Svärd · 4 weeks ago master
  2. 4e5e056 Update license headers by Anton Moberg · 6 weeks ago
  3. 031f4c1 Add support for float32 in inference_runner by Henrik Hoglind · 6 weeks ago
  4. 097d292 Trademark information and missing license files by Kristofer Jonsson · 2 months ago 21.02
  5. c823bcf Use namespace for ethosu kernel headers by Per Åstrand · 4 months ago

Linux driver stack for Arm(R) Ethos(TM)-U

The Linux driver stack for Arm(R) Ethos(TM)-U provides an example of how a rich operating system like Linux can dispatch inferences to an Arm Cortex(R)-M subsystem, consisting of an Arm Cortex-M of choice and an Arm Ethos-U NPU.


The driver stack comes with a CMake based build system. Cross compile for an Arm CPU can for example be done with the provided toolchain file.

$ mkdir build
$ cd build
$ cmake .. -DCMAKE_TOOLCHAIN_FILE=../cmake/toolchain/aarch64-linux-gnu.cmake -DKDIR=<Kernel directory>
$ make


The kernel driver uses the mailbox APIs as a doorbell mechanism.

/ {
  reserved-memory {
    #address-cells = <2>;
    #size-cells = <2>;

    ethosu_msg: ethosu_msg@80000000 {
      compatible = "shared-dma-pool";
      reg = <0 0x80000000 0 0x00040000>;

    ethosu_reserved: ethosu_reserved@80040000 {
      compatible = "shared-dma-pool";
      reg = <0 0x80040000 0 0x00040000>;

  ethosu_mailbox: mhu@6ca00000 {
    compatible = "arm,mhu", "arm,primecell";
    reg = <0x0 0x6ca00000 0x0 0x1000>;
    interrupts = <0 168 4>;
    interrupt-names = "npu_rx";
    #mbox-cells = <1>;
    clocks = <&soc_refclk100mhz>;
    clock-names = "apb_pclk";

  ethosu {
    #address-cells = <2>;
    #size-cells = <2>;

    compatible = "arm,ethosu";
    reg = <0 0x80000000 0 0x00010000>,
          <0 0x80010000 0 0x00010000>;
    reg-names = "in_queue", "out_queue";
    memory-region = <&ethosu_reserved>;
    dma-ranges = <0 0x60000000 0 0x80000000 0 0x20000000>;
    mboxes= <&ethosu_mailbox 0>, <&ethosu_mailbox 0>;
    mbox-names = "tx", "rx";


The kernel drivers are provided under a GPL v2 license. All other software componantes are provided under an Apache 2.0 license.

Please see LICENSE-APACHE-2.0.txt and LICENSE-GPL-2.0.txt for more information.


The Arm Ethos-U project welcomes contributions under the Apache-2.0 license.

Before we can accept your contribution, you need to certify its origin and give us your permission. For this process we use the Developer Certificate of Origin (DCO) V1.1 (

To indicate that you agree to the terms of the DCO, you "sign off" your contribution by adding a line with your name and e-mail address to every git commit message. You must use your real name, no pseudonyms or anonymous contributions are accepted. If there are more than one contributor, everyone adds their name and e-mail to the commit message.

Author: John Doe \<\>
Date:   Mon Feb 29 12:12:12 2016 +0000

Title of the commit

Short description of the change.
Signed-off-by: John Doe
Signed-off-by: Foo Bar

The contributions will be code reviewed by Arm before they can be accepted into the repository.


Please see Security.

Trademark notice

Arm, Cortex and Ethos are registered trademarks of Arm Limited (or its subsidiaries) in the US and/or elsewhere.