Crosstooling

Crosstooling is the practice of creating and using a cross-compilation toolchain to build software for a target architecture on a different host architecture. The goal is to produce executables that run on the target system without requiring a native build environment on that system. Crosstooling is essential in embedded development, where the target devices may be small, appliances, or otherwise unable to host a full development toolchain.

A cross-toolchain typically includes a cross compiler (such as gcc or clang configured for the target), cross-binutils (assembler, linker, and related tools), and a target C library (commonly glibc, musl, or uClibc) along with the corresponding header files and sysroot. The host system builds these components and then installs them with a target-specific prefix, producing tools like arm-linux-gnueabi-gcc, arm-linux-gnueabi-ld, and similar binaries. The resulting tools generate executables for the target while run on the host system.

Common workflows use automated toolchain builders such as crosstool-ng, Buildroot, or OpenEmbedded to configure, compile, and assemble the toolchain according to specified target architectures, ABIs, and C libraries. The choice of library and ABI, as well as endianness and toolchain triplets, affects compatibility with the target system.

Crosstooling is contrasted with native toolchains, which build for the same architecture as the host. It enables cross-compilation workflows, improves portability, and supports reproducible builds for development boards, embedded devices, and cross-platform software. Challenges include managing ABI compatibility, sysroots, and library availability for the target.