liminix/devices/qemu/default.nix

# This "device" generates images that can be used with the QEMU
# emulator. The default output is a directory containing separate
# kernel (uncompressed vmlinux) and initrd (squashfs) images

{
  system = {
    crossSystem = {
      config = "mips-unknown-linux-musl";
      gcc = {
        abi = "32";
        arch = "mips32";          # maybe mips_24kc-
      };
    };
  };

  module = {pkgs, ... }: {
    kernel = {
      src = pkgs.pkgsBuildBuild.fetchurl {
        name = "linux.tar.gz";
        url = "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.19.16.tar.gz";
        hash = "sha256-m4NeoEsCEK0HSIKTZ6zYTgk1fD3W0PSOMXN6fyHpkP8=";
      };
      config = {
        MIPS_MALTA= "y";
        CPU_LITTLE_ENDIAN= "n";
        CPU_BIG_ENDIAN= "y";
        CPU_MIPS32_R2= "y";

        SQUASHFS = "y";
        SQUASHFS_XZ = "y";

        VIRTIO_MENU = "y";
        PCI = "y";
        VIRTIO_PCI = "y";
        BLOCK = "y";
        VIRTIO_BLK = "y";
        NETDEVICES = "y";
        VIRTIO_NET = "y";

        SERIAL_8250= "y";
        SERIAL_8250_CONSOLE= "y";
      };
    };
    device.defaultOutput = "directory";
  };
}