Li Dongshan - How to make OpenHarmony support Bluetooth low energy chip GR551x

Editor's note: During the ecological development of OpenHarmony, a large number of outstanding code contributors have emerged. This topic aims to recognize contributions and share experience. The content in this article is from guest interviews and does not represent the views of the OpenHarmony Working Committee.

Hello everyone, my name is Li Dongshan, from Shenzhen Huiding Technology Co., Ltd., and I am currently a R&D engineer in the BLE product development department. From September 2021, I will be responsible for connecting the BLE SoC GR551x to OpenAtom OpenHarmony ("OpenHarmony" for short). ) ecological adaptation task. As of January this year, the code has been reviewed and merged into the trunk. I am very happy to witness the transition from 0 to 1 and the successful integration into the trunk with the team. This is the first time I have participated in such a large-scale open source project. I hope Share your feelings and experiences during the project development process with everyone.

Q1 As a well-known technical expert in the development field, why did you initially choose to join the OpenHarmony ecosystem and participate in open source co-construction? What do you think is the most attractive point of the OpenHarmony project?

OpenHarmony is a distributed operating system for the era of all scenarios, all connections, and all intelligence. It is oriented towards the Internet of Everything, which is very suitable for the application direction of our BLE SoC products. We contribute to the prosperity and development of the Internet of Everything and thousands of industries.

The OpenHarmony code follows business-friendly open source protocols such as Apache 2.0. All enterprises, institutions and individuals can use the OpenHarmony open source code and combine their own advantages to make operating system distributions and terminal products in various fields.

Q2 When did you form the OpenHarmony open source project team? After how long it took to complete the adaptation of the GR5515 Starter Kit development board, the core code has been integrated into the trunk, and now it has been selected as the "Monthly Code Contribution Star" by the OpenHarmony PMC Committee, which is really amazing! Is it convenient for you to tell us about this product, or this experience? You have achieved such good results in such a short period of time. What are your "secrets"?

We started investing resources to adapt OpenHarmony in September 2021. After more than two months of hard work, our first Bluetooth LE lightweight device chip GR551x series SoC was adapted to OpenHarmony. It successfully passed the OpenHarmony compatibility test on November 18, 2021, and was officially incorporated on January 7, 2022. OpenHarmony trunk.

$$ GR5515 Starter Kit Adaptation Code Repository$$

The development board adaptation work can be completed in a short time not only because of the concerted efforts of our ecological team partners, but also because of OpenHarmony's complete development platform and tool chain, excellent code framework, and rich documentation resources. At the beginning, our warehouse was incubated on SIG. After two graduation defense reviews, the code was merged into the trunk. I am very grateful to the teachers in the community for their professional guidance and support.

Q3 can develop such an excellent product and integrate the core code into the trunk, you and your team must have paid a lot. Could you please share with us the entire process of developing this product, including the early, middle, and late stages, what work have you done, and how much manpower and resources have you invested?

In the early stage of the development board adaptation, we studied and investigated the OpenHarmony lightweight system, and began to try the adaptation after fully evaluating the feasibility. Everything is difficult at the beginning. At the beginning of adapting to the V1.1.2-LTS version, from building the development environment, getting familiar with the build system, and porting the first line of code, I solved many problems and stepped on many pits. Finally, after two weeks, the system is running stably on our SoC.

In the middle of the project, we upgraded to V3.0.0-LTS. Version 3.0 introduced many new features. We began to adapt HDF driver, BLE interface, file system, low power consumption, etc., and passed the compatibility test.

In the later stage of the project, we aligned with the master version of the trunk. The master version introduced the advanced design concept of separating board and soc. We have refactored and optimized the code framework a lot. After the code structure and specifications meet the requirements, the code is merged into the OpenHarmony trunk.

Goodix Technology is very optimistic about OpenHarmony. We continue to invest manpower in this project. At present, we have basically completed the adaptation of the first BLE Soc GR5515 chip. In the future, we will continue to optimize and maintain the adapted code. Participate in the co-construction of the graphic display of the lightweight system and the direction of BLE IoT.

Q4 What technical or other difficulties have you and your team encountered throughout the development process? How are these problems solved one by one? In the process of solving these problems, what valuable experiences or lessons have you drawn?

In the early stage of development, there were almost no guidance documents on the Internet for the adaptation of the lightweight system of the ARM architecture, and the construction environment was also very complicated. There were only 3 development boards for reference. I know how to add our code, but I don't know how to build it, and I was almost "dissuaded" by the various difficulties encountered. Fortunately, OpenHarmony comes with a sample development board based on RSIC-V architecture. After in-depth study of its compilation framework and adaptation details, we ported the SDK to OpenHarmony and built it successfully.

OpenHarmony has very comprehensive support for ARM and RSIC-V architectures. Cortex-M core related arch porting liteos-m has been done for us. Porting a new development board only needs to focus on compiling and building, BSP porting, and XTS testing. , business function development.

Q5 What is your biggest surprise since joining the OpenHarmony ecosystem? Or what specific gains?

Since joining the OpenHarmony ecosystem, I have personally felt that it is developing so fast. From the original version 1.0 to the current version 3.0, each version will bring many practical updates, more and more development boards, and more documents. The more abundant, the more active the community exchanges, and the easier it is for developers to participate in co-construction.

I have also been learning OpenHarmony. During the learning process, I have learned a lot of advanced concepts in code architecture, which has brought great help to my usual development work. I have always insisted on sharing my learning experience and open source transplantation cases through blogs. .

Q6 What aspects of OpenHarmony are expected to be improved and provide more support in the future?

After more than a year of rapid development, OpenHarmony has done a very good job in compilation and construction, code architecture, documentation support, and community building. I personally expect that OpenHarmony and its supporting IDE DevEco Device Tool can be popularized as soon as possible, and promote the adaptation and support of many development boards, which is conducive to bringing a more convenient experience to developers and end customers.

Q7 OpenHarmony is still in the development and exploration stage. Many co-construction units and ecological partners still do not know how to play open source projects, or do not know how to start development. Could you please share with us a piece of experience that you think is the most important or worth sharing?

The output of open source projects will provide developers with more learning paths and light up the way forward for many developers. I encountered a lot of technical difficulties in the development process. When I couldn't ask for help from others, I found inspiration and ideas by studying other people's open source code. Open source is actually an efficient way to learn from each other and make progress together.

Q8 Open questions, you can speak freely. Do you have anything else to tell everyone?

I am very grateful to OpenHarmony for providing us with such an excellent operating system. I am very happy to be able to participate in the open source co-construction and contribute my little power to open source. From the "ignorant" Xiaobai at the beginning, he grew up with OpenHarmony. Although the process was full of challenges, he also gained a lot. I really feel the rapid development of OpenHarmony, and I hope that more companies and developers will participate in the construction of OpenHarmony's prosperous ecosystem.