Sysroots

A sysroot is a directory hierarchy that contains the necessary header files and libraries for a particular target system. It is primarily used in cross-compilation environments where a program is being compiled on one system (the host) but intended to run on a different system (the target). The sysroot acts as a substitute for the target system's root filesystem, allowing the compiler to find the correct versions of headers and libraries for the target architecture and operating system.

When building software for embedded systems or different operating system architectures, developers often use a sysroot to ensure that the compiled binaries are compatible with the target environment. This prevents issues that can arise from using headers and libraries that are specific to the host system. The sysroot typically includes a copy of the target system's standard library, as well as any other essential development files.

The concept of a sysroot is crucial for toolchains, which are sets of software development tools. A cross-compilation toolchain will often be configured to use a specific sysroot. This ensures that when the compiler encounters an include directive or a library dependency, it looks within the designated sysroot directory rather than the host system's directories. This separation is vital for maintaining the integrity and correctness of the cross-compilation process. Without a properly configured sysroot, the resulting executables might fail to link or run on the target platform.