To compile the OS for the CPU, we need a cross compiler, a cross linker, etc.. It allows us to compile for another target than your current OS.

We have made a Docker image, to build and run it, run the next instructions:

docker build -t osdev .

If you want to run qemu in graphical mode from the container (Forwarding X socket),

docker run -it -e DISPLAY=$DISPLAY \
 -v /tmp/.X11-unix:/tmp/.X11-unix \
 -v $PWD:/osdev osdev

if you just want to compile,

docker run -it -v $PWD:/osdev osdev

You can build it by hand from this source https://wiki.osdev.org/GCC_Cross-Compiler.

To read the documentaion Doc.