在Yocto中为何需要NATIVESDK？请说明其作用

Great question! Let's start by confirming your understanding of native first—you've got it exactly right! Packages with BBCLASSEXTEND = "native" are built to run on your build host (like your x86_64 Linux machine) and exist solely to support the Yocto build system itself. For example, cmake-native provides the cmake binary that other recipes (using CMake) call to generate build configurations for the target embedded system. These native tools live in Yocto's temporary build directories and are only used during the build process.

Now, onto NATIVESDK—it serves a completely different purpose, focused on external application development rather than Yocto's internal build workflow:

• It creates a distributable cross-development SDK
  NATIVESDK packages are part of a standalone SDK that you can generate and install on any compatible host machine (not just the one running Yocto builds). This SDK gives external developers all the tools they need to cross-compile applications for your target embedded system, without requiring them to set up or understand the full Yocto build environment.

• Pre-configured for target architecture
  Unlike native tools (which run on the host), NATIVESDK tools are set up to target your embedded system's architecture (e.g., ARM, RISC-V). For example, nativesdk-cmake isn't just a host cmake binary—it's a version of CMake pre-configured to use the cross-compiler, target-specific headers, and libraries from your Yocto project. When a developer sources the SDK's environment script, tools like cmake, gcc, or make automatically point to the right target resources.

• Separates build system tools from developer tools
  Think of it this way:

  • native tools are for Yocto to build your embedded OS image.
  • NATIVESDK tools are for you (or other developers) to build applications that run on that OS image, without re-running the entire Yocto build every time you tweak your app.

For example, if you're developing a custom IoT application for an ARM-based target, you can generate the NATIVESDK once, install it on your laptop, and then compile, test, and iterate on your app quickly—no need to mess with Yocto's build directories or recipes after the initial SDK setup.

内容的提问来源于stack exchange，提问作者Ravi Kumar