Makefile: add a target to (cross-)compile Linux
By moving away from a single config file, and instead maintain a separate list of CONFIG_* options, we can achieve two things:
- make it easy to apply these options on different architectures
- Avoid duplicating the instructions of how to compile the kernel
between the
README
andconfig/linux_config_x86_64.sample
.
With this step done, this commit also adds a new Makefile target that simplifies the compilation of Linux, and even cross-compilation!