An SDK is a set of tools we can use outside Yocto/OE. These tools generally include a compiler, linker, debugger, libraries, and external headers. This set of compilation tools is called a toolchain. With the Raspberry Pi (or other embedded platforms), the toolchain is often composed of crosstools, which are tools executed on one architecture that produce a binary for use in another architecture.
The following figure depicts the process of cross-compilation:
The Yocto/OE build system can be used to generate a cross-compilation toolchain and matching sysroot folder for a target system.
Note
The sysroot folder contains the shared libraries, headers, and utilities that are used in the process of building recipes,
With this build system, there are several ways of generating an SDK that conforms to our Raspberry Pi platform.