For my Operating Systems class, we were presented with kernel code to build and tinker around with. In my typical fashion, I decided to go overboard and implement the entire build process in Nix, rather than mess around with a fragile VM environment. This flake builds a cross compiler/linker toolchain, as well as a cross-targeted gdb package, most notably with GCC 5.4, binutils 2.26.1.

Each of the folders in ./kernel are built as a flake output. A given folder can be compiled with nix build .#name, such as nix build .#01_gdb.

Additionally, there are the gcc, binutils, and gdb outputs for the cross-compiler versions of those programs. For easy access, these (plus qemu and nasm) are included in the devshell, for which direnv is also provided.

Finally, for easy running, each of the kernel folders also have a series of run scripts built for use with nix run:

• name-run runs the kernel in normal QEMU
• name-curses runs the kernel in QEMU using curses
• name-debug runs the kernel in QEMU using curses, with the gdb target enabled
• name-gdb runs gdb with the kernel elf, kernel sources, etc, included. Automatically targets the gdb host from name-debug
• name is an alias to name-curses

This flake only supports building on x86_64-linux out of the box. Edit flake.nix if you are using another type of system.