I created a docker container that hosts the gcc cross-compiler I used to build my own OS:

https://hub.docker.com/r/brett/gcc-cross-x86_64-elf/

It hosts the gcc 7.1 x86_64-elf compiler with redzone disabled.

If you don't want to use the docker container, you can view the dockerfile to see the steps required to build the cross-compiler yourself:

https://github.com/beevik/docker/tree/master/gcc-cross-x86_6...