commit	116a635581f292cb4882ea1a086f842904f85c3c	[log] [tgz]
author	Kristofer Jonsson <kristofer.jonsson@arm.com>	Thu Aug 20 17:25:23 2020 +0200
committer	Kristofer Jonsson <kristofer.jonsson@arm.com>	Thu Aug 27 13:58:01 2020 +0200
tree	96ed12cebd8dbf9f1dc7b8f116be7d528779a2bb
parent	cd13a572fe223fe95cd58c5b55b659885fb7b4cd [diff]

Linux driver stack for Arm Ethos-U

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

Licenses

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

Building

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

DTB

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

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

    ethosu_msg: ethosu_msg@80000000 {
      compatible = "shared-dma-pool";
      reg = <0 0x80000000 0 0x00040000>;
      no-map;
    };

    ethosu_reserved: ethosu_reserved@80040000 {
      compatible = "shared-dma-pool";
      reg = <0 0x80040000 0 0x00040000>;
      no-map;
    };
  };

  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";
  };
};