From 013e4c396c97767beed3051c51a6eb6780397b8f Mon Sep 17 00:00:00 2001
From: Raito Bezarius <masterancpp@gmail.com>
Date: Mon, 16 Sep 2024 18:14:39 +0200
Subject: [PATCH] feat: repair CI and cleanup cross-compilation mechanism

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>
---
 ci.nix                            | 22 ++++-------------
 devices/qemu/default.nix          |  5 +++-
 devices/zyxel-nwa50ax/default.nix |  4 ++-
 lon.lock                          | 15 +++++++++++
 lon.nix                           | 41 +++++++++++++++++++++++++++++++
 modules/base.nix                  | 11 +++++++++
 modules/outputs/tftpboot.nix      |  8 ------
 7 files changed, 79 insertions(+), 27 deletions(-)
 create mode 100644 lon.lock
 create mode 100644 lon.nix

diff --git a/ci.nix b/ci.nix
index ec345dd..07d26f1 100644
--- a/ci.nix
+++ b/ci.nix
@@ -1,21 +1,15 @@
 {
-  nixpkgs
-, unstable
-, liminix
+  sources ? import ./lon.nix
+, nixpkgs ? sources.nixpkgs
+, unstable ? nixpkgs
+, liminix ? ./.
 , ... }:
 let
-  inherit (builtins) map;
-  pkgs = (import nixpkgs {});
+  pkgs = (import nixpkgs { });
   borderVmConf =  ./bordervm.conf-example.nix;
   inherit (pkgs.lib.attrsets) genAttrs;
   devices = [
-    "gl-ar750"
-    "gl-mt300a"
-    "gl-mt300n-v2"
     "qemu"
-    "qemu-aarch64"
-    "qemu-armv7l"
-    "tp-archer-ax23"
     "zyxel-nwa50ax"
   ];
   vanilla = ./vanilla-configuration.nix;
@@ -44,12 +38,6 @@ let
                   imports = [ ./modules/all-modules.nix ];
                 };
               }).outputs.optionsJson;
-            installers = map (f: "system.outputs.${f}") [
-              "vmroot"
-              "mtdimage"
-              "ubimage"
-            ];
-            inherit (pkgs.lib) concatStringsSep;
         in pkgs.stdenv.mkDerivation {
           name = "liminix-doc";
           nativeBuildInputs = with pkgs; [
diff --git a/devices/qemu/default.nix b/devices/qemu/default.nix
index b6e860d..fe98952 100644
--- a/devices/qemu/default.nix
+++ b/devices/qemu/default.nix
@@ -1,7 +1,7 @@
 # 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
-{
+rec {
   system = {
     crossSystem = {
       config = "mips-unknown-linux-musl";
@@ -41,6 +41,9 @@
       ../../modules/arch/mipseb.nix
       ../families/qemu.nix
     ];
+
+    nixpkgs.hostPlatform = system.crossSystem;
+
     kernel = {
       config = {
         MIPS_MALTA= "y";
diff --git a/devices/zyxel-nwa50ax/default.nix b/devices/zyxel-nwa50ax/default.nix
index a7834dc..2b4813d 100644
--- a/devices/zyxel-nwa50ax/default.nix
+++ b/devices/zyxel-nwa50ax/default.nix
@@ -1,4 +1,4 @@
-{
+rec {
   system = {
     crossSystem = {
       config = "mipsel-unknown-linux-musl";
@@ -135,6 +135,8 @@
         ../../modules/zyxel-dual-image
       ];
 
+      nixpkgs.hostPlatform = system.crossSystem;
+
       filesystem = dir {
         lib = dir {
           firmware = dir {
diff --git a/lon.lock b/lon.lock
new file mode 100644
index 0000000..50209e4
--- /dev/null
+++ b/lon.lock
@@ -0,0 +1,15 @@
+{
+  "version": "1",
+  "sources": {
+    "nixpkgs": {
+      "type": "GitHub",
+      "fetchType": "tarball",
+      "owner": "nixos",
+      "repo": "nixpkgs",
+      "branch": "nixos-unstable-small",
+      "revision": "b6227cadb5123c7e4cb159bf6f9f5705ae081a47",
+      "url": "https://github.com/nixos/nixpkgs/archive/b6227cadb5123c7e4cb159bf6f9f5705ae081a47.tar.gz",
+      "hash": "sha256-KFR30GNFhjzXl0kVEn+KK4xrFr0gggb1NBroP8ukbxY="
+    }
+  }
+}
diff --git a/lon.nix b/lon.nix
new file mode 100644
index 0000000..5f320ea
--- /dev/null
+++ b/lon.nix
@@ -0,0 +1,41 @@
+# Generated by lon. Do not modify!
+let
+
+  lock = builtins.fromJSON (builtins.readFile ./lon.lock);
+
+  # Override with a path defined in an environment variable. If no variable is
+  # set, the original path is used.
+  overrideFromEnv =
+    name: path:
+    let
+      replacement = builtins.getEnv "LON_OVERRIDE_${name}";
+    in
+    if replacement == "" then
+      path
+    else
+    # this turns the string into an actual Nix path (for both absolute and
+    # relative paths)
+    if builtins.substring 0 1 replacement == "/" then
+      /. + replacement
+    else
+      /. + builtins.getEnv "PWD" + "/${replacement}";
+
+  fetchSource =
+    args@{ fetchType, ... }:
+    if fetchType == "git" then
+      builtins.fetchGit {
+        url = args.url;
+        ref = args.branch;
+        rev = args.revision;
+        narHash = args.hash;
+      }
+    else if fetchType == "tarball" then
+      builtins.fetchTarball {
+        url = args.url;
+        sha256 = args.hash;
+      }
+    else
+      builtins.throw "Unsupported source type ${fetchType}";
+
+in
+builtins.mapAttrs (name: args: overrideFromEnv name (fetchSource args)) lock.sources
diff --git a/modules/base.nix b/modules/base.nix
index d2182c6..41550e6 100644
--- a/modules/base.nix
+++ b/modules/base.nix
@@ -69,6 +69,14 @@ in {
         default = "uimage";
       };
       tftp = {
+        commandLine = mkOption {
+          type = types.listOf types.str;
+          default = config.boot.commandLine;
+          description = ''
+            TFTP-specific command line.
+            Defaults to the classical one if unset.
+          '';
+        };
         loadAddress = mkOption {
           type = types.ints.unsigned;
           description = ''
@@ -98,6 +106,9 @@ in {
     };
   };
   config = {
+    # By default, we enable cross-compilation support.
+    nixpkgs.buildPlatform = lib.mkDefault builtins.currentSystem;
+
     defaultProfile.packages = with pkgs;
       [ s6 s6-init-bin execline s6-linux-init s6-rc ];
 
diff --git a/modules/outputs/tftpboot.nix b/modules/outputs/tftpboot.nix
index a8fc4dc..4fd139d 100644
--- a/modules/outputs/tftpboot.nix
+++ b/modules/outputs/tftpboot.nix
@@ -41,14 +41,6 @@ in {
       type = types.bool;
       default = false;
     };
-    commandLine = mkOption {
-      type = types.listOf types.str;
-      default = config.boot.commandLine;
-      description = ''
-        TFTP-specific command line.
-        Defaults to the classical one if unset.
-      '';
-    };
   };
   options.system.outputs = {
     tftpboot = mkOption {