Linux Kernel Module Cheat

We have made a crazy setup that allows you to just cd into submodules/gem5, and edit Python scripts directly there.

This is not normally possible with Buildroot, since normal Buildroot packages first copy files to the output directory ($(./getvar -a <arch> buildroot_build_build_dir)/<pkg>), and then build there.

So if you modified the Python scripts with this setup, you would still need to ./build to copy the modified files over.

For gem5 specifically however, we have hacked up the build so that we cd into the submodules/gem5 tree, and then do an out of tree build to out/common/gem5.

Another advantage of this method is the we factor out the arm and aarch64 gem5 builds which are identical and large, as well as the smaller arch generic pieces.

Using Buildroot for gem5 is still convenient because we use it to:

The out of build tree is required, because otherwise Buildroot would copy the output build of all archs to each arch directory, resulting in arch^2 build copies, which is significant.