官术网_书友最值得收藏!

Middleware

Some of the features may already have a well-known solution that has been previously implemented by a single developer, a community, or an enterprise. Solutions may be generic, or perhaps designed for a different platform, or even coming from outside the embedded world. In any case, it is always worth looking for libraries for any data transformation, protocol implementation, or subsystem model that might already have been coded and is waiting to be integrated in our project.

A number of open source libraries and software components are ready be included in embedded projects and allow us to implement a broader set of functionalities. Integrating components from open source projects is particularly useful to deliver standard functionalities. There is a vast choice of well-established open source implementations designed for embedded devices that can be easily integrated on embedded projects. These include:

  • Real-time operating systems
  • Cryptography libraries
  • TCP/IP, 6LoWPAN, and other network protocols
  • Transport Layer Security (TLS) libraries
  • Filesystems
  • IoT message queue protocols
  • Parsers

Some components from these categories are described in more detail later in this book.

Basing the software upon an operating system allows us to manage memory areas and thread execution. In this case, threads execute independently from each other, and it is even possible to implement memory separation among threads, and between running threads and the kernel. This approach is advisable when the complexity of the design increases, or when there are well-known blocking points in the modules that cannot be redesigned. If an operating system is used, other libraries usually require multithreading support, which can be enabled at compile time if present.

The decision of integrating third-party libraries must be evaluated by measuring the resources needed, in terms of code size and memory used, to perform specific tasks on the target platform. As the whole firmware is distributed as a single executable file, all the licenses of the components must be compatible, and the integration must not violate the license terms of any of its single components.

主站蜘蛛池模板: 仁怀市| 衡东县| 鹰潭市| 琼中| 松原市| 上高县| 枣阳市| 湾仔区| 安泽县| 海安县| 抚松县| 日土县| 萨嘎县| 黄平县| 临安市| 宣恩县| 长春市| 灵宝市| 阿坝县| 临高县| 盐城市| 新野县| 凌源市| 阿荣旗| 娱乐| 海兴县| 武乡县| 凤山市| 鄄城县| 新化县| 广州市| 宁蒗| 同仁县| 瓦房店市| 渝北区| 鸡东县| 英吉沙县| 金坛市| 泾阳县| 广丰县| 陇西县|