From bb335050fd91446c0ab5a8319619e825495e37f4 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Sat, 2 Dec 2023 15:31:55 +0000
Subject: [PATCH] derivation that produces /boot

---
 modules/outputs.nix          |  1 +
 modules/outputs/extlinux.nix | 37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 modules/outputs/extlinux.nix

diff --git a/modules/outputs.nix b/modules/outputs.nix
index 2c69484..df2343d 100644
--- a/modules/outputs.nix
+++ b/modules/outputs.nix
@@ -12,6 +12,7 @@ in
   imports = [
     ./squashfs.nix
     ./outputs/vmroot.nix
+    ./outputs/extlinux.nix
   ];
   options = {
     system.outputs = {
diff --git a/modules/outputs/extlinux.nix b/modules/outputs/extlinux.nix
new file mode 100644
index 0000000..c8db8be
--- /dev/null
+++ b/modules/outputs/extlinux.nix
@@ -0,0 +1,37 @@
+{
+  config
+, pkgs
+, lib
+, ...
+}:
+let
+  inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep;
+  cfg = config.boot.loader.extlinux;
+  o = config.system.outputs;
+  cmdline = concatStringsSep " " config.boot.commandLine;
+in {
+  options.system.outputs.extlinux = mkOption {
+    type = types.package;
+    # description = "";
+  };
+  options.boot.loader.extlinux.enable = mkEnableOption "extlinux";
+
+  config =  { # mkIf cfg.enable {
+    system.outputs.extlinux = pkgs.runCommand "extlinux" {} ''
+      mkdir $out
+      cd $out
+      ln -s ${o.dtb} dtb
+      ln -s ${o.initramfs} initramfs
+      gzip -9f < ${o.kernel} > kernel.gz
+      cat > extlinux.conf << _EOF
+      menu title Liminix
+      timeout 100
+      label Liminix
+        kernel kernel.gz
+        initrd initramfs
+        fdt dtb
+        append ${cmdline}
+      _EOF
+    '';
+  };
+}