VM Image

ekaos/eval-config.nix

@@ -42,3 +42,9 @@ in
     etc
     ;
 }
+// lib.optionalAttrs (eval.config.virtualisation.enable or false) {
+  inherit (eval.config.system.build) diskImage vm;
+}
+// lib.optionalAttrs (eval.config.isoImage.enable or false) {
+  inherit (eval.config.system.build) isoImage;
+}

ekaos/examples/vm-image.nix

@@ -0,0 +1,60 @@
+# Example: Build and run an ekaos VM image
+#
+# Build the disk image:
+#   nix-build -E '(import ./ekaos { system = "x86_64-linux"; modules = [ ./ekaos/examples/vm-image.nix ]; }).diskImage'
+#
+# Run the VM:
+#   nix-build -E '(import ./ekaos { system = "x86_64-linux"; modules = [ ./ekaos/examples/vm-image.nix ]; }).vm'
+#   ./result
+#
+# The disk image is a qcow2 file suitable for use with QEMU, libvirt, or
+# other hypervisors. The VM script launches QEMU with EFI boot.
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  system.ekaos.version = "24.11";
+  system.ekaos.label = "ekaos-vm";
+
+  # Boot
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+  boot.loader.efi.efiSysMountPoint = "/boot";
+  boot.kernelPackages = pkgs.linuxPackages_6_12;
+
+  # Initrd for loading virtio modules before root mount
+  boot.initrd.enable = true;
+  boot.initrd.availableKernelModules = [
+    "virtio_pci"
+    "virtio_blk"
+    "ext4"
+  ];
+
+  # VM settings
+  virtualisation.enable = true;
+  virtualisation.memorySize = 2048;
+  virtualisation.cores = 2;
+  virtualisation.diskSize = 8192;
+  virtualisation.serialConsole = true;
+
+  # Serial console for VM
+  boot.kernelParams = [
+    "console=ttyS0,115200"
+    "console=tty1"
+    "root=UUID=F222513B-DED1-49FA-B591-20CE86A2FE7F"
+  ];
+
+  # Packages
+  environment.systemPackages = with pkgs; [
+    coreutils
+    util-linux
+    systemd
+    bash
+    less
+    curl
+  ];
+}

ekaos/lib/make-disk-image.nix

@@ -389,6 +389,7 @@ let
       util-linux
       parted
       e2fsprogs
+      dosfstools
       lkl
       config.system.build.nixos-install
       nixos-enter
@@ -759,7 +760,7 @@ let
           # nix builds in the target image if sandboxing is turned off (through
           # __noChroot for example).
           export HOME=$TMPDIR
-          NIXOS_INSTALL_BOOTLOADER=1 nixos-enter --root $mountPoint -- /nix/var/nix/profiles/system/bin/switch-to-configuration boot
+          nixos-enter --root $mountPoint -- /bin/sh -c 'EKAOS_INSTALL_BOOTLOADER=1 /nix/var/nix/profiles/system/bin/switch-to-configuration boot'
         ''}
 
         # Set the ownerships of the contents. The modes are set in preVM.