This repository contains a device driver for the Arm(R) Ethos(TM)-U NPU.

The source code comes with a CMake based build system. The driver is expeced to be cross compiled for any of the supported Arm Cortex(R)-M CPUs, which will require the user to setup a custom toolchain file.

The user is also required to define CMAKE_SYSTEM_PROCESSOR for the target CPU, for example cortex-m55+nodsp+nofp. This can be done either in the toolchain file or on the command line.

$ mkdir build
$ cd build
$ cmake .. -DCMAKE_TOOLCHAIN_FILE=<toolchain> -DCMAKE_SYSTEM_PROCESSOR=cortex-m<nr><features>
$ make

For running the driver on Arm CPUs which are configured with datacache, the cache maintenance functions in the driver are exported with weakly linked symbols that should be overriden. An example implementation using the CMSIS primitives found in cachel1_armv7.h could be as below:

extern "C" {
void ethosu_flush_dcache(uint32_t *p, size_t bytes) {
    if (p)
        SCB_CleanDCache_by_Addr(p, bytes);
    else
        SCB_CleanDCache();
}

void ethosu_invalidate_dcache(uint32_t *p, size_t bytes) {
    if (p)
        SCB_InvalidateDCache_by_Addr(p, bytes);
    else
        SCB_InvalidateDCache();
}
}

The Arm Ethos-U core driver is provided under an Apache-2.0 license. Please see LICENSE.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 (https://developercertificate.org).

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 \<[email protected]\>
Date:   Mon Feb 29 12:12:12 2016 +0000

Title of the commit

Short description of the change.
   
Signed-off-by: John Doe [email protected]
Signed-off-by: Foo Bar [email protected]

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

Please see Security.

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