Cross toolchain for systems not yet in nixpkgs

Help
1

I’m trying to get a cross-compiler toolchain for the m68k-elf target similar to this:
https://aur.archlinux.org/packages/m68k-elf-toolchain/
I’ve found a really pretty solution in the wiki which works for a large number of CPUs that can be parsed by lib/systems/parse.nix.
This doesn’t however work in this case, since specifying config=m68k-elf results in an Unknown CPU type: m68k error.

I did also try to directly specify a platform attribute like this:

crossSystem = {
  config = "m68k-elf";
  platform = {
    bits = 32;
    family = "m68k";
  };
};

But this doesn’t work.

It seems the most straightforward way would be to fork nixpkgs and add the m68k CPU to the list of options.
However I’d like to know if there is a way to do this without forking nixpkgs.

2

It seems the most straightforward way would be to fork nixpkgs
and add the m68k CPU to the list of options.
However I’d like to know if there is a way to do this without
forking nixpkgs.

I don’t believe there is a way to do this without forking. However,
I think its reasonable to add the CPU metadata to Nixpkgs and keep
the toolchain in an overlay.