From c1101d3af5f5d4566dfdd57200af36d9d798f08d Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Mon, 8 Jan 2024 18:58:07 +0000
Subject: [PATCH] make extlinux work with liminix-rebuild

add /boot to the systemConfiguration closure
---
 examples/rotuer.nix           |  3 ++-
 modules/outputs/extlinux.nix  |  8 ++++++--
 pkgs/systemconfig/default.nix | 15 +++++++++++++--
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/examples/rotuer.nix b/examples/rotuer.nix
index 51ce22b..d2d9f64 100644
--- a/examples/rotuer.nix
+++ b/examples/rotuer.nix
@@ -44,11 +44,12 @@ in rec {
     ../modules/ntp
     ../modules/ssh
     ../modules/outputs/btrfs.nix
-
+    ../modules/outputs/extlinux.nix
   ];
   hostname = "rotuer";
   rootfsType = "btrfs";
   rootOptions = "subvol=@";
+  boot.loader.extlinux.enable = true;
 
   services.hostap = svc.hostapd.build {
     interface = config.hardware.networkInterfaces.wlan;
diff --git a/modules/outputs/extlinux.nix b/modules/outputs/extlinux.nix
index 9f46c0a..17fde2a 100644
--- a/modules/outputs/extlinux.nix
+++ b/modules/outputs/extlinux.nix
@@ -6,6 +6,7 @@
 }:
 let
   inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep;
+  inherit (pkgs.pseudofile) dir symlink;
   cfg = config.boot.loader.extlinux;
   o = config.system.outputs;
   cmdline = concatStringsSep " " config.boot.commandLine;
@@ -17,7 +18,7 @@ in {
   };
   options.boot.loader.extlinux.enable = mkEnableOption "extlinux";
 
-  config =  { # mkIf cfg.enable {
+  config = mkIf cfg.enable {
     system.outputs.extlinux = pkgs.runCommand "extlinux" {} ''
       mkdir $out
       cd $out
@@ -27,7 +28,7 @@ in {
       mkdir extlinux
       cat > extlinux/extlinux.conf << _EOF
       menu title Liminix
-      timeout 100
+      timeout 40
       label Liminix
         kernel /boot/kernel
         # initrd /boot/initramfs
@@ -35,5 +36,8 @@ in {
         ${if wantsDtb then "fdt /boot/dtb" else ""}
       _EOF
     '';
+    filesystem = dir {
+      boot = symlink config.system.outputs.extlinux;
+    };
   };
 }
diff --git a/pkgs/systemconfig/default.nix b/pkgs/systemconfig/default.nix
index dae4221..129993f 100644
--- a/pkgs/systemconfig/default.nix
+++ b/pkgs/systemconfig/default.nix
@@ -84,8 +84,19 @@ in attrset:
       #!/bin/sh -e
       prefix=\''${1-/}
       src=\''${prefix}$out
-      mkdir -p \$prefix/persist
-      cp -v -fP \$src/bin/* \$src/etc/* \$prefix/persist
+      dest=\$prefix
+      ${# if we are running on a normal mounted system then
+        # the actual device root is mounted on /persist
+        # and /nix is bind mounted from /persist/nix
+        # (see the code in preinit). So we need to check for this
+        # case otherwise we will install into a ramfs/rootfs
+        ""
+      }
+      if test -d $dest/persist; then dest=$dest/persist; fi
+      cp -v -fP \$src/bin/* \$src/etc/* \$dest
+      ${if attrset ? boot then ''
+        (cd \$prefix && rm ./boot && ln -sf ${lib.strings.removePrefix "/" attrset.boot.target} ./boot)
+      '' else ""}
       EOF
       chmod +x $out/bin/install
     '';