HummingBird SDK is developed based on Modified NMSIS, all the SoCs supported in it are following the Modified NMSIS-Core Device Templates Guidance.

So this HummingBird SDK can be treated as a software guide for how to use NMSIS.

The build system we use in HummingBird SDK is Makefile, it support both Windows and Linux, and when we develop HummingBird SDK build system, we keep it simple, so it make developer can easily port this HummingBird SDK software code to other IDEs.

Click Overview to learn more about the HummingBird SDK project overview.

For example, we have ported HummingBird SDK to use Segger embedded Studio and PlatformIO.

Directory Structure

To learn deeper about HummingBird SDK project, the directory structure is a good start point.

Below, we will describe our design about the HummingBird SDK directory structure:

Here is the directory structure for this HummingBird SDK.

├── application
│   ├── baremetal
│   ├── freertos
│   ├── ucosii
│   └── rtthread
├── Build
│   ├── gmsl
│   ├── Makefile.base
│   ├── Makefile.conf
│   ├── Makefile.components
│   ├── Makefile.core
│   ├── Makefile.files
│   ├── Makefile.global
│   ├── Makefile.misc
│   ├── Makefile.rtos
│   ├── Makefile.rules
│   └── Makefile.soc
├── doc
│   ├── build
│   ├── source
│   ├── Makefile
│   └── requirements.txt
│   ├── Core
│   ├── DSP
│   ├── NN
│   └── Library
├── OS
│   ├── FreeRTOS
│   ├── UCOSII
│   └── RTThread
├── SoC
│   ├── hbird
│   └── hbirdv2
├── test
│   ├── core
│   ├── ctest.h
│   ├── LICENSE
│   └── README.md
├── Makefile
├── README.md
├── setup.bat
└── setup.sh
  • application

    This directory contains all the application softwares for this HummingBird SDK.

    The application code can be divided into mainly 4 parts, which are:

    • Baremetal applications, which will provide baremetal applications without any OS usage, these applications will be placed in application/baremetal/ folder.

    • FreeRTOS applications, which will provide FreeRTOS applications using FreeRTOS RTOS, placed in application/freertos/ folder.

    • UCOSII applications, which will provide UCOSII applications using UCOSII RTOS, placed in application/ucosii/ folder.

    • RTThread applications, which will provide RT-Thread applications using RT-Thread RTOS, placed in application/rtthread/ folder.

  • SoC

    This directory contains all the supported SoCs for this HummingBird SDK, the directory name for SoC and its boards should always in lower case.

    Here we mainly support HummingBird processor cores running in Hummingbird FPGA evaluation board, the support package placed in SoC/hbird/ and SoC/hbirdv2/.

    In each SoC’s include directory, hbird_sdk_soc.h must be provided, and include the soc header file, for example, SoC/hbird/Common/Include/hbird_sdk_soc.h.

    In each SoC Board’s include directory, hbird_sdk_hal.h must be provided, and include the board header file, for example, SoC/hbird/Board/hbird_eval/Include/hbird_sdk_hal.h.

  • Build

    This directory contains the key part of the build system based on Makefile for HummingBird SDK.


    This directory contains the modified NMSIS header files, which is widely used in this HummingBird SDK, you can check the NMSIS_VERSION file to know the current NMSIS version used in HBird-SDK.

    We will also sync the changes in NMSIS project when it provided a new release.

  • OS

    This directory provided two RTOS package we suppported which are FreeRTOS and UCOSII.


    HummingBird SDK license file.


    NMSIS Version file. It will show current NMSIS version used in HummingBird SDK.

  • Makefile

    An external Makefile just for build, run, debug application without cd to any coresponding application directory, such as application/baremetal/helloworld/.

  • setup.sh

    HummingBird SDK environment setup script for Linux. You need to create your own setup_config.sh.


    In the $NUCLEI_TOOL_ROOT for Linux, you need to have Nuclei RISC-V GNU GCC toolchain and OpenOCD installed as below.

    ├── gcc
    │   ├── bin
    │   ├── include
    │   ├── lib
    │   ├── libexec
    │   ├── riscv-nuclei-elf
    │   └── share
    └── openocd
        ├── bin
        ├── contrib
        ├── distro-info
        ├── OpenULINK
        ├── scripts
        └── share
  • setup.bat

    HummingBird SDK environment setup bat script for Windows. You need to create your own setup_config.bat.

    set NUCLEI_TOOL_ROOT=\path\to\your_tool_root

    In the %NUCLEI_TOOL_ROOT% for Windows, you need to have Nuclei RISC-V GNU GCC toolchain, necessary Windows build tools and OpenOCD installed as below.

    ├── build-tools
    │   ├── bin
    │   ├── gnu-mcu-eclipse
    │   └── licenses
    ├── gcc
    │   ├── bin
    │   ├── include
    │   ├── lib
    │   ├── libexec
    │   ├── riscv-nuclei-elf
    │   └── share
    └── openocd
        ├── bin
        ├── contrib
        ├── distro-info
        ├── OpenULINK
        ├── scripts
        └── share

Project Components

This HummingBird SDK project components is list as below:

  • HummingBird RISC-V Processor: How HummingBird RISC-V Processor Core is used in HummingBird SDK

  • SoC: How HummingBird RISC-V processor code based SoC device is supported in HummingBird SDK

  • Board: How HummingBird RISC-V based SoC’s Board is supported in HummingBird SDK

  • Peripheral: How to use the peripheral driver in HummingBird SDK

  • RTOS: What RTOSes are supported in HummingBird SDK

  • Application: How to use pre-built applications in HummingBird SDK