Porting GCC to your OS

Difficulty level
Master

This page or section is a work in progress and may thus be incomplete. Its content may be changed in the near future.

Read GCC Cross-Compiler.
Make a OS Specific Toolchain.
Read Hosted GCC Cross-Compiler.
Have a sufficient C Library. GCC is fairly portable and needs the C standard library, and some extensions from POSIX. It needs fork and exec, for instance, to run the assembler and linker. You will need a C++ standard library (such as libstdc++) as GCC is now written in C++.
Cross-compile libgmp, libmpc, libmpfr and other dependencies with instructions in Cross-Porting Software.
Likewise cross-compile Binutils and GCC, but pass the special configure options --with-build-sysroot=/your/sysroot and --with-sysroot=/. The option --with-build-sysroot option uses that sysroot for the duration of the build, but the final program does not remember it. --with-sysroot=/ should not be needed or should be set to the empty string, but some binutils/gcc versions are buggy and require it, which has the disadvantage the final toolchain might use //foo instead of /foo. You should only pass these options to the Binutils and GCC builds, some other packages also have a --with-sysroot option, but it instead means a libtool feature you should not use.
Become self-hosting and complete Bare Bones II. Congratulations.

See Also