From 59d57327fa7004789db94b5bfaefd6dc263bb510 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 10:51:04 +0200
Subject: [PATCH 01/12] Pass only required fields to rescueSystem

---
 bootloader/rescue/default.nix | 6 +++---
 default.nix                   | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/bootloader/rescue/default.nix b/bootloader/rescue/default.nix
index 4ecd113a..56c38dfb 100644
--- a/bootloader/rescue/default.nix
+++ b/bootloader/rescue/default.nix
@@ -1,5 +1,5 @@
 { stdenv, lib
-, application
+, safeProductName, fullProductName
 , squashfsTools, closureInfo, makeInitrd, linkFarm
 , importFromNixos
 , writeScript, dialog
@@ -23,7 +23,7 @@ let
     do
 
       ${dialog}/bin/dialog --clear --title "" \
-        --backtitle "${application.fullProductName} - Rescue System" \
+        --backtitle "${fullProductName} - Rescue System" \
         --nocancel \
         --menu "Please Select an action" 0 0 0 \
         "wipe-user-data" "Delete all user data." \
@@ -94,7 +94,7 @@ in
       '';
     };
     networking = {
-      hostName = "${application.safeProductName}-rescue";
+      hostName = "${safeProductName}-rescue";
       # enable wpa_supplicant
       wireless = {
         enable = true;
diff --git a/default.nix b/default.nix
index 8004ce2a..baed5f59 100644
--- a/default.nix
+++ b/default.nix
@@ -87,7 +87,7 @@ let
 
     # Rescue system
     rescueSystem = callPackage ./bootloader/rescue {
-        application = application;
+      inherit safeProductName fullProductName;
     };
 
     # Installer ISO image

From d872d776276011f386a8ac3328b80afc3c6c71bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 11:15:58 +0200
Subject: [PATCH 02/12] Make skeleton parts be sub-packages of installer

---
 default.nix                          | 20 +++++---------------
 installer/default.nix                | 28 ++++++++++++++++++++++------
 installer/install-playos/default.nix | 12 ++----------
 3 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/default.nix b/default.nix
index baed5f59..c2b76276 100644
--- a/default.nix
+++ b/default.nix
@@ -80,24 +80,14 @@ let
     # USB live system
     live = callPackage ./live { application = application; };
 
-    # Installation script
-    install-playos = callPackage ./installer/install-playos {
-      grubCfg = ./bootloader/grub.cfg;
-    };
-
-    # Rescue system
-    rescueSystem = callPackage ./bootloader/rescue {
-      inherit safeProductName fullProductName;
-    };
-
-    # Installer ISO image
+    # Installer script and ISO (PlayOS skeleton)
     installer = callPackage ./installer {};
 
     # Script to deploy updates
     deploy-update = callPackage ./deployment/deploy-update {
       application = application;
       live = if buildLive then live else "";
-      installer = if buildInstaller then installer else "";
+      installer = if buildInstaller then installer.isoImage else "";
     };
 
     # RAUC bundle
@@ -139,7 +129,7 @@ let
   };
 
   releaseDisk = pkgs.callPackage ./testing/disk/release.nix {
-    inherit (releaseValidationComponents) install-playos;
+    install-playos = releaseValidationComponents.installer.install-playos;
   };
 in
 
@@ -149,7 +139,7 @@ with pkgs; stdenv.mkDerivation {
   buildInputs = [
     rauc
     (python3.withPackages(ps: with ps; [pyparted]))
-    components.install-playos
+    components.installer.install-playos
   ];
 
   buildCommand = ''
@@ -176,7 +166,7 @@ with pkgs; stdenv.mkDerivation {
   ''
   # Installer ISO image
   + lib.optionalString buildInstaller ''
-    ln -s ${components.installer}/iso/${components.safeProductName}-installer-${components.version}.iso $out/${components.safeProductName}-installer-${components.version}.iso
+    ln -s ${components.installer.isoImage}/iso/${components.safeProductName}-installer-${components.version}.iso $out/${components.safeProductName}-installer-${components.version}.iso
   ''
   # RAUC bundle
   + lib.optionalString buildBundle ''
diff --git a/installer/default.nix b/installer/default.nix
index 5da8101f..c3b96775 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -1,18 +1,34 @@
 # Build NixOS system
 { config, lib, pkgs
-, version, safeProductName, fullProductName, greeting, install-playos
+, systemImage
+, version, safeProductName, fullProductName, greeting
+, kioskUrl, updateUrl
 , squashfsCompressionOpts
 }:
 let
   nixos = pkgs.importFromNixos "";
 
+  # Rescue system
+  rescueSystem = pkgs.callPackage ../bootloader/rescue {
+    inherit safeProductName fullProductName squashfsCompressionOpts;
+  };
+
+  # Installation script
+  install-playos = pkgs.callPackage ./install-playos {
+    grubCfg = ../bootloader/grub.cfg;
+    inherit kioskUrl updateUrl rescueSystem systemImage version;
+  };
+
   configuration = (import ./configuration.nix) {
     inherit config pkgs lib install-playos version safeProductName fullProductName greeting squashfsCompressionOpts;
   };
 
-in
-(nixos {
-  inherit configuration;
-  system = "x86_64-linux";
-}).config.system.build.isoImage
 
+  isoImage = (nixos {
+    inherit configuration;
+    system = "x86_64-linux";
+  }).config.system.build.isoImage;
+in
+{
+  inherit install-playos isoImage;
+}
diff --git a/installer/install-playos/default.nix b/installer/install-playos/default.nix
index 0a994338..532b685f 100644
--- a/installer/install-playos/default.nix
+++ b/installer/install-playos/default.nix
@@ -1,13 +1,4 @@
-{ stdenv
-, substituteAll
-, makeWrapper
-, grub2_efi
-, e2fsprogs
-, dosfstools
-, utillinux
-, python3
-, pv
-, closureInfo
+{ pkgs
 
 , systemImage
 , rescueSystem
@@ -16,6 +7,7 @@
 , updateUrl
 , kioskUrl
 }:
+with pkgs;
 let
   systemClosureInfo = closureInfo { rootPaths = [ systemImage ]; };
 

From 94c6bfe93b4edc6a26b71f10e411fc572704bfdb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 11:44:28 +0200
Subject: [PATCH 03/12] Make installer and sub-components independant of system
 image nixpkgs

Also semi-convert configuration into a module.
---
 bootloader/rescue/default.nix |  3 +--
 installer/configuration.nix   |  7 ++++---
 installer/default.nix         | 21 +++++++++++++++------
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/bootloader/rescue/default.nix b/bootloader/rescue/default.nix
index 56c38dfb..b3eae4ff 100644
--- a/bootloader/rescue/default.nix
+++ b/bootloader/rescue/default.nix
@@ -1,13 +1,12 @@
 { stdenv, lib
 , safeProductName, fullProductName
 , squashfsTools, closureInfo, makeInitrd, linkFarm
-, importFromNixos
+, nixos
 , writeScript, dialog
 , vim, grub2_efi, rauc
 , squashfsCompressionOpts}:
 with lib;
 let
-  nixos = importFromNixos "";
 
   squashfsCompressionParams =
     if (squashfsCompressionOpts == null)
diff --git a/installer/configuration.nix b/installer/configuration.nix
index 9c7b8ea1..b6281424 100644
--- a/installer/configuration.nix
+++ b/installer/configuration.nix
@@ -1,10 +1,11 @@
-{ config, pkgs, lib, install-playos, version, safeProductName, fullProductName, greeting, squashfsCompressionOpts, ... }:
+{ install-playos, version, safeProductName, fullProductName, greeting, squashfsCompressionOpts, ... }:
 
-with lib;
 
+{ modulesPath, lib, ... }:
+with lib;
 {
   imports = [
-    (pkgs.importFromNixos "modules/installer/cd-dvd/iso-image.nix")
+    "${modulesPath}/installer/cd-dvd/iso-image.nix"
   ];
 
   # Custom label when identifying OS
diff --git a/installer/default.nix b/installer/default.nix
index c3b96775..d8c87299 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -1,16 +1,23 @@
 # Build NixOS system
-{ config, lib, pkgs
-, systemImage
+{ systemImage
 , version, safeProductName, fullProductName, greeting
 , kioskUrl, updateUrl
 , squashfsCompressionOpts
 }:
 let
-  nixos = pkgs.importFromNixos "";
+  nixpkgs = builtins.fetchTarball {
+    # release-24.11 2025-02-10
+    url = "https://github.com/NixOS/nixpkgs/archive/edd84e9bffdf1c0ceba05c0d868356f28a1eb7de.tar.gz";
+    sha256 = "1gb61gahkq74hqiw8kbr9j0qwf2wlwnsvhb7z68zhm8wa27grqr0";
+  };
+
+  pkgs = import nixpkgs { };
+
+  nixos = import "${nixpkgs}/nixos";
 
   # Rescue system
   rescueSystem = pkgs.callPackage ../bootloader/rescue {
-    inherit safeProductName fullProductName squashfsCompressionOpts;
+    inherit nixos safeProductName fullProductName squashfsCompressionOpts;
   };
 
   # Installation script
@@ -20,12 +27,14 @@ let
   };
 
   configuration = (import ./configuration.nix) {
-    inherit config pkgs lib install-playos version safeProductName fullProductName greeting squashfsCompressionOpts;
+    inherit install-playos version safeProductName fullProductName greeting squashfsCompressionOpts;
   };
 
 
   isoImage = (nixos {
-    inherit configuration;
+    configuration = {
+      imports = [ configuration ];
+    };
     system = "x86_64-linux";
   }).config.system.build.isoImage;
 in

From d2db7c6178ea8e4d79dd56269e76d156aa65aa24 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 12:04:31 +0200
Subject: [PATCH 04/12] Move bootloader to a be sub-component of installer

---
 {bootloader => installer/bootloader}/grub.cfg           | 0
 {bootloader => installer/bootloader}/rescue/default.nix | 0
 installer/default.nix                                   | 4 ++--
 3 files changed, 2 insertions(+), 2 deletions(-)
 rename {bootloader => installer/bootloader}/grub.cfg (100%)
 rename {bootloader => installer/bootloader}/rescue/default.nix (100%)

diff --git a/bootloader/grub.cfg b/installer/bootloader/grub.cfg
similarity index 100%
rename from bootloader/grub.cfg
rename to installer/bootloader/grub.cfg
diff --git a/bootloader/rescue/default.nix b/installer/bootloader/rescue/default.nix
similarity index 100%
rename from bootloader/rescue/default.nix
rename to installer/bootloader/rescue/default.nix
diff --git a/installer/default.nix b/installer/default.nix
index d8c87299..3b4db786 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -16,13 +16,13 @@ let
   nixos = import "${nixpkgs}/nixos";
 
   # Rescue system
-  rescueSystem = pkgs.callPackage ../bootloader/rescue {
+  rescueSystem = pkgs.callPackage ./bootloader/rescue {
     inherit nixos safeProductName fullProductName squashfsCompressionOpts;
   };
 
   # Installation script
   install-playos = pkgs.callPackage ./install-playos {
-    grubCfg = ../bootloader/grub.cfg;
+    grubCfg = ./bootloader/grub.cfg;
     inherit kioskUrl updateUrl rescueSystem systemImage version;
   };
 

From b2660917f575f3dd60daa5dc15081d08c0b9796d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 12:20:12 +0200
Subject: [PATCH 05/12] Use the same RAUC package in installer and runtime
 system

---
 installer/default.nix                                      | 7 ++++++-
 ...pt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch | 0
 {pkgs => installer}/rauc/default.nix                       | 0
 pkgs/default.nix                                           | 5 ++++-
 4 files changed, 10 insertions(+), 2 deletions(-)
 rename {pkgs => installer}/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch (100%)
 rename {pkgs => installer}/rauc/default.nix (100%)

diff --git a/installer/default.nix b/installer/default.nix
index 3b4db786..0c7aa1b3 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -11,7 +11,12 @@ let
     sha256 = "1gb61gahkq74hqiw8kbr9j0qwf2wlwnsvhb7z68zhm8wa27grqr0";
   };
 
-  pkgs = import nixpkgs { };
+  overlay =
+    self: super: {
+      rauc = (import ./rauc) super;
+    };
+
+  pkgs = import nixpkgs { overlays = [ overlay ]; };
 
   nixos = import "${nixpkgs}/nixos";
 
diff --git a/pkgs/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch b/installer/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch
similarity index 100%
rename from pkgs/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch
rename to installer/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch
diff --git a/pkgs/rauc/default.nix b/installer/rauc/default.nix
similarity index 100%
rename from pkgs/rauc/default.nix
rename to installer/rauc/default.nix
diff --git a/pkgs/default.nix b/pkgs/default.nix
index 9f0ef639..cac1982c 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -13,7 +13,10 @@ let
 
       importFromNixos = path: import (nixpkgs + "/nixos/" + path);
 
-      rauc = (import ./rauc) super;
+      # TODO: replace with something along the lines of:
+      #   rauc = (import ../installer/pkgs).rauc;
+      # to ensure 100% identical package and deps?
+      rauc = (import ../installer/rauc) super;
 
       ocamlPackages = super.ocamlPackages.overrideScope (self: super: {
         semver = self.callPackage ./ocaml-modules/semver {};

From 661a34ffce037202e3f5e2bbd53ea047199bbc2a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 12:38:46 +0200
Subject: [PATCH 06/12] Drop the need to share greeting formatter with
 installer

---
 installer/configuration.nix | 18 +++++++++++++++++-
 installer/default.nix       |  4 ++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/installer/configuration.nix b/installer/configuration.nix
index b6281424..7114d73c 100644
--- a/installer/configuration.nix
+++ b/installer/configuration.nix
@@ -1,8 +1,24 @@
-{ install-playos, version, safeProductName, fullProductName, greeting, squashfsCompressionOpts, ... }:
+{ install-playos, version, safeProductName, fullProductName, squashfsCompressionOpts, ... }:
 
 
 { modulesPath, lib, ... }:
 with lib;
+let
+    # TODO: WIP ^_^
+    greeting = label: ''
+             ░░░░
+           ░▒▒▒▒▒▒▒  ░    ▒
+        ▒▒▒▒▒   ░░▒▒░░░▒▒▒▒▒ ▒▒
+      ▒▒          ░░░░░░░   ▒▒▒▒▒
+     ▒▒▒      ▲           ▲     ▒▒
+     ▒░░                         ░
+       ░░░                       ░
+         ░░░▒▒      ▒▒░░░  ▒▒▒   ░░ ${label}
+             ▒▒▒▒▒▒▒▒    ░░░▒▒▒░░░
+    '';
+
+in
+
 {
   imports = [
     "${modulesPath}/installer/cd-dvd/iso-image.nix"
diff --git a/installer/default.nix b/installer/default.nix
index 0c7aa1b3..dab9a585 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -1,6 +1,6 @@
 # Build NixOS system
 { systemImage
-, version, safeProductName, fullProductName, greeting
+, version, safeProductName, fullProductName
 , kioskUrl, updateUrl
 , squashfsCompressionOpts
 }:
@@ -32,7 +32,7 @@ let
   };
 
   configuration = (import ./configuration.nix) {
-    inherit install-playos version safeProductName fullProductName greeting squashfsCompressionOpts;
+    inherit install-playos version safeProductName fullProductName squashfsCompressionOpts;
   };
 
 

From 9b4bd675f69ffc3bfd4f6dc3a506a0992b9bf5e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 15:06:41 +0200
Subject: [PATCH 07/12] Combine system metadat into single attrset within
 installer

---
 installer/bootloader/rescue/default.nix |  6 +++---
 installer/configuration.nix             |  3 ++-
 installer/default.nix                   | 22 +++++++++++++++-------
 installer/install-playos/default.nix    |  9 ++++-----
 4 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/installer/bootloader/rescue/default.nix b/installer/bootloader/rescue/default.nix
index b3eae4ff..601c91e0 100644
--- a/installer/bootloader/rescue/default.nix
+++ b/installer/bootloader/rescue/default.nix
@@ -1,5 +1,5 @@
 { stdenv, lib
-, safeProductName, fullProductName
+, systemMetadata
 , squashfsTools, closureInfo, makeInitrd, linkFarm
 , nixos
 , writeScript, dialog
@@ -22,7 +22,7 @@ let
     do
 
       ${dialog}/bin/dialog --clear --title "" \
-        --backtitle "${fullProductName} - Rescue System" \
+        --backtitle "${systemMetadata.fullProductName} - Rescue System" \
         --nocancel \
         --menu "Please Select an action" 0 0 0 \
         "wipe-user-data" "Delete all user data." \
@@ -93,7 +93,7 @@ in
       '';
     };
     networking = {
-      hostName = "${safeProductName}-rescue";
+      hostName = "${systemMetadata.safeProductName}-rescue";
       # enable wpa_supplicant
       wireless = {
         enable = true;
diff --git a/installer/configuration.nix b/installer/configuration.nix
index 7114d73c..29f025af 100644
--- a/installer/configuration.nix
+++ b/installer/configuration.nix
@@ -1,8 +1,9 @@
-{ install-playos, version, safeProductName, fullProductName, squashfsCompressionOpts, ... }:
+{ install-playos, squashfsCompressionOpts, systemMetadata, ... }:
 
 
 { modulesPath, lib, ... }:
 with lib;
+with systemMetadata;
 let
     # TODO: WIP ^_^
     greeting = label: ''
diff --git a/installer/default.nix b/installer/default.nix
index dab9a585..ba884c22 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -1,8 +1,8 @@
 # Build NixOS system
-{ systemImage
-, version, safeProductName, fullProductName
-, kioskUrl, updateUrl
-, squashfsCompressionOpts
+{ squashfsCompressionOpts
+, systemImage
+# TODO: combine this into a single systemMetadata attrset that is defined in the top-level default.nix
+, safeProductName, fullProductName, kioskUrl, updateUrl, version
 }:
 let
   nixpkgs = builtins.fetchTarball {
@@ -20,19 +20,27 @@ let
 
   nixos = import "${nixpkgs}/nixos";
 
+  systemMetadata = {
+    inherit safeProductName fullProductName kioskUrl updateUrl version;
+  };
+
   # Rescue system
   rescueSystem = pkgs.callPackage ./bootloader/rescue {
-    inherit nixos safeProductName fullProductName squashfsCompressionOpts;
+    inherit nixos squashfsCompressionOpts;
+    inherit systemMetadata;
   };
 
+
   # Installation script
   install-playos = pkgs.callPackage ./install-playos {
     grubCfg = ./bootloader/grub.cfg;
-    inherit kioskUrl updateUrl rescueSystem systemImage version;
+    inherit rescueSystem;
+    inherit systemImage systemMetadata;
   };
 
   configuration = (import ./configuration.nix) {
-    inherit install-playos version safeProductName fullProductName squashfsCompressionOpts;
+    inherit install-playos squashfsCompressionOpts;
+    inherit systemMetadata;
   };
 
 
diff --git a/installer/install-playos/default.nix b/installer/install-playos/default.nix
index 532b685f..8bddd18f 100644
--- a/installer/install-playos/default.nix
+++ b/installer/install-playos/default.nix
@@ -3,9 +3,7 @@
 , systemImage
 , rescueSystem
 , grubCfg
-, version
-, updateUrl
-, kioskUrl
+, systemMetadata
 }:
 with pkgs;
 let
@@ -14,11 +12,12 @@ let
   python = python3.withPackages(ps: with ps; [pyparted]);
 in
 stdenv.mkDerivation {
-  name = "install-playos-${version}";
+  name = "install-playos-${systemMetadata.version}";
 
   src = substituteAll {
     src = ./install-playos.py;
-    inherit grubCfg systemImage rescueSystem systemClosureInfo version updateUrl kioskUrl;
+    inherit grubCfg systemImage rescueSystem systemClosureInfo;
+    inherit (systemMetadata) version kioskUrl updateUrl;
     inherit python;
   };
 

From a4b26206a050d370cc83a4a41f4dab07c5a3d4cf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 15:13:31 +0200
Subject: [PATCH 08/12] Add TODOs on hard-coded paths that depend on skeleton

---
 base/self-update/default.nix |  2 ++
 installer/pkgs/default.nix   | 17 +++++++++++++++++
 system-image/default.nix     |  2 ++
 3 files changed, 21 insertions(+)
 create mode 100644 installer/pkgs/default.nix

diff --git a/base/self-update/default.nix b/base/self-update/default.nix
index 759411c9..7c1d1afb 100644
--- a/base/self-update/default.nix
+++ b/base/self-update/default.nix
@@ -33,6 +33,8 @@ in
     };
 
     environment.etc."rauc/system.conf" = {
+      # TODO: disk labels/paths and statusfile path should be supplied/defined
+      # by skeleton/installer
       text = ''
         [system]
         compatible=dividat-play-computer
diff --git a/installer/pkgs/default.nix b/installer/pkgs/default.nix
new file mode 100644
index 00000000..a8e867f0
--- /dev/null
+++ b/installer/pkgs/default.nix
@@ -0,0 +1,17 @@
+let
+  nixpkgs = builtins.fetchTarball {
+    # release-24.11 2025-02-10
+    url = "https://github.com/NixOS/nixpkgs/archive/edd84e9bffdf1c0ceba05c0d868356f28a1eb7de.tar.gz";
+    sha256 = "1gb61gahkq74hqiw8kbr9j0qwf2wlwnsvhb7z68zhm8wa27grqr0";
+  };
+
+  overlay =
+    self: super: {
+      rauc = (import ./rauc) super;
+
+      nixos = import "${nixpkgs}/nixos";
+    };
+in
+import nixpkgs {
+  overlays = [ overlay ];
+}
diff --git a/system-image/default.nix b/system-image/default.nix
index ca8d1302..27dab61a 100644
--- a/system-image/default.nix
+++ b/system-image/default.nix
@@ -16,6 +16,7 @@ let nixos = pkgs.importFromNixos ""; in
     ] ++ extraModules;
 
     # Storage
+    # TODO: should be defined by installer/skeleton config module
     fileSystems = {
       "/boot" = {
         device = "/dev/disk/by-label/ESP";
@@ -28,6 +29,7 @@ let nixos = pkgs.importFromNixos ""; in
         device = "/dev/root";
         options = [ "ro" ];
       };
+      # TODO: should be defined by installer/skeleton config module
       persistentDataPartition.device = "/dev/disk/by-label/data";
     };
 

From 0b878beaf8ab22af8a7a23de8b60f429acc3b59b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 15:37:05 +0200
Subject: [PATCH 09/12] Add TODO with general plan regarding installer/

---
 installer/default.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/installer/default.nix b/installer/default.nix
index ba884c22..eaf6de8b 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -1,4 +1,7 @@
-# Build NixOS system
+# TODO: rename this to "skeleton" that exposes several components:
+# - [ ] skeleton configuration params (partition labels, hard-coded paths like /boot/status.ini)
+# - [x] the installer script (for e2e and release validation tests)
+# - [x] the installer ISO
 { squashfsCompressionOpts
 , systemImage
 # TODO: combine this into a single systemMetadata attrset that is defined in the top-level default.nix

From 91122057ae847fccb1e642fc6d0695e08ef440f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 16:23:08 +0200
Subject: [PATCH 10/12] Make installer pkgs re-usable and re-use RAUC with deps
 in system

---
 installer/default.nix                         | 20 ++++---------------
 ...GRUB-primary-slot-to-allow-for-2-uns.patch |  0
 installer/{ => pkgs}/rauc/default.nix         |  0
 pkgs/default.nix                              |  6 ++----
 4 files changed, 6 insertions(+), 20 deletions(-)
 rename installer/{ => pkgs}/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch (100%)
 rename installer/{ => pkgs}/rauc/default.nix (100%)

diff --git a/installer/default.nix b/installer/default.nix
index eaf6de8b..1e22e925 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -8,20 +8,7 @@
 , safeProductName, fullProductName, kioskUrl, updateUrl, version
 }:
 let
-  nixpkgs = builtins.fetchTarball {
-    # release-24.11 2025-02-10
-    url = "https://github.com/NixOS/nixpkgs/archive/edd84e9bffdf1c0ceba05c0d868356f28a1eb7de.tar.gz";
-    sha256 = "1gb61gahkq74hqiw8kbr9j0qwf2wlwnsvhb7z68zhm8wa27grqr0";
-  };
-
-  overlay =
-    self: super: {
-      rauc = (import ./rauc) super;
-    };
-
-  pkgs = import nixpkgs { overlays = [ overlay ]; };
-
-  nixos = import "${nixpkgs}/nixos";
+  pkgs = import ./pkgs;
 
   systemMetadata = {
     inherit safeProductName fullProductName kioskUrl updateUrl version;
@@ -29,7 +16,8 @@ let
 
   # Rescue system
   rescueSystem = pkgs.callPackage ./bootloader/rescue {
-    inherit nixos squashfsCompressionOpts;
+    inherit (pkgs) nixos;
+    inherit squashfsCompressionOpts;
     inherit systemMetadata;
   };
 
@@ -47,7 +35,7 @@ let
   };
 
 
-  isoImage = (nixos {
+  isoImage = (pkgs.nixos {
     configuration = {
       imports = [ configuration ];
     };
diff --git a/installer/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch b/installer/pkgs/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch
similarity index 100%
rename from installer/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch
rename to installer/pkgs/rauc/0001-Adapt-notion-of-GRUB-primary-slot-to-allow-for-2-uns.patch
diff --git a/installer/rauc/default.nix b/installer/pkgs/rauc/default.nix
similarity index 100%
rename from installer/rauc/default.nix
rename to installer/pkgs/rauc/default.nix
diff --git a/pkgs/default.nix b/pkgs/default.nix
index cac1982c..be2af8b5 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -13,10 +13,8 @@ let
 
       importFromNixos = path: import (nixpkgs + "/nixos/" + path);
 
-      # TODO: replace with something along the lines of:
-      #   rauc = (import ../installer/pkgs).rauc;
-      # to ensure 100% identical package and deps?
-      rauc = (import ../installer/rauc) super;
+      # use RAUC from installer/skeleton
+      rauc = (import ../installer/pkgs).rauc;
 
       ocamlPackages = super.ocamlPackages.overrideScope (self: super: {
         semver = self.callPackage ./ocaml-modules/semver {};

From dc92081eb0a81873503c5d51bca12b09376a48ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 16:34:29 +0200
Subject: [PATCH 11/12] TEST: downgrade installer nixpkgs to previous release

Forcing divergence between system and installer / skeleton to check
whether e2e tests pass and etc.
---
 installer/pkgs/default.nix | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/installer/pkgs/default.nix b/installer/pkgs/default.nix
index a8e867f0..6aa30bb9 100644
--- a/installer/pkgs/default.nix
+++ b/installer/pkgs/default.nix
@@ -1,8 +1,8 @@
 let
   nixpkgs = builtins.fetchTarball {
-    # release-24.11 2025-02-10
-    url = "https://github.com/NixOS/nixpkgs/archive/edd84e9bffdf1c0ceba05c0d868356f28a1eb7de.tar.gz";
-    sha256 = "1gb61gahkq74hqiw8kbr9j0qwf2wlwnsvhb7z68zhm8wa27grqr0";
+    # nixos-24.05 2024-10-07
+    url = "https://github.com/nixos/nixpkgs/archive/ecbc1ca8ffd6aea8372ad16be9ebbb39889e55b6.tar.gz";
+    sha256 = "0yfaybsa30zx4bm900hgn3hz92javlf4d47ahdaxj9fai00ddc1x";
   };
 
   overlay =

From 27d4d71b365e237da01c5988d45bdc8bbae59dd3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignas=20Vy=C5=A1niauskas?= <ignas@dividat.ch>
Date: Thu, 5 Mar 2026 16:44:57 +0200
Subject: [PATCH 12/12] Fix: pass rescueSystem to disk

A bit silly, since it is only needed for computing the size for /boot.

Could (Should?) be hard-coded instead?
---
 default.nix           | 6 +++++-
 installer/default.nix | 3 ++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/default.nix b/default.nix
index c2b76276..b1e1a039 100644
--- a/default.nix
+++ b/default.nix
@@ -98,7 +98,11 @@ let
     testingToplevel = callPackage ./testing/system { application = application; };
 
     # Disk image containing pre-installed system
-    disk = if diskBuildEnabled then callPackage ./testing/disk {} else null;
+    disk =
+      if diskBuildEnabled then
+        callPackage ./testing/disk { inherit (installer) install-playos rescueSystem; }
+      else
+        null;
 
     # Script for spinning up VMs
     run-in-vm = callPackage ./testing/run-in-vm {};
diff --git a/installer/default.nix b/installer/default.nix
index 1e22e925..22740010 100644
--- a/installer/default.nix
+++ b/installer/default.nix
@@ -1,6 +1,7 @@
 # TODO: rename this to "skeleton" that exposes several components:
 # - [ ] skeleton configuration params (partition labels, hard-coded paths like /boot/status.ini)
 # - [x] the installer script (for e2e and release validation tests)
+# - [x] the rescueSystem (for e2e and release validation tests)
 # - [x] the installer ISO
 { squashfsCompressionOpts
 , systemImage
@@ -43,5 +44,5 @@ let
   }).config.system.build.isoImage;
 in
 {
-  inherit install-playos isoImage;
+  inherit install-playos isoImage rescueSystem;
 }