Overview
Introduction
The HummingBird RISC-V Software Development Kit (SDK) is an open-source software platform to speed up the software development of SoCs based on HummingBird RISC-V Processor Cores.
This HummingBird SDK is built based on the modified version of NMSIS, user can access all the APIs provided by NMSIS and also the APIs that provided by HummingBird SDK which mainly for on-board peripherals access such as GPIO, UART, SPI and I2C, etc.
HummingBird SDK provides a good start base for embedded developers which will help them simplify software development and improve time-to-market through well-designed software framework.
Note
The NMSIS used in this HummingBird SDK is modified for HummingBird RISC-V Core, which is not compatiable with Nuclei NMSIS, take care.
HummingBird SDK is developed based on Nuclei SDK 0.2.4 release, and will diverge in future.
To get a pdf version of this documentation, please click HBird SDK Document
Design and Architecture
The HummingBird SDK general design and architecture are shown in the block diagram as below.

HummingBird SDK Design and Architecture Diagram
As HummingBird SDK Design and Architecture Diagram shown, The HummingBird SDK provides the following features:
HummingBird RISC-V Core API service is built on top of a modified version of NMSIS, so silicon vendors of HummingBird RISC-V processors can easily port their SoCs to HummingBird SDK, and quickly evaluate software on their SoC.
NMSIS-NN and NMSIS-DSP library can be also used in HummingBird SDK, and the prebuilt libraries are included in NMSIS/Library folder of HummingBird SDK.
Mainly support two HummingBird RISC-V Processor based SoCs, HummingBird SoC.
Provided realtime operation system service via FreeRTOS, UCOSII and RT-Thread
Provided bare-metal service for embedded system software beginners and resource-limited use-cases.
Currently HummingBird SDK didn’t define any common device APIs to access GPIO/I2C/SPI/UART devices, it still relied on the device/peripheral APIs from firmware libraries from various silicon vendors.
Applications are logically seperated into three parts:
General applications for all HummingBird RISC-V Processors: In the HummingBird SDK software code, the applications provided are all general applications which can run on all HummingBird RISC-V Processors, with basic UART service to provide
printf
function.HummingBird SoC applications: These applications are not included in the HummingBird SDK software code, it is maintained seperately, it will use resource from HummingBird SoC and its evaluation boards to develop applications, which will not be compatiable with different boards.
Get Started
Please refer to Quick Startup to get started to take a try with HummingBird SDK.
Contributing
Contributing to HummingBird SDK is welcomed, if you have any issue or pull request want to open, you can take a look at Contributing section.
Copyright
Copyright (c) 2019 - Present, Nuclei System Technology. All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the Nuclei System Technology., nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. NY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
License
HummingBird SDK is an opensource project licensed by Apache License 2.0.