From 42e59d81053735c288c56ac477fe9ff1a2dea2a5 Mon Sep 17 00:00:00 2001
From: Samuel Dionne-Riel <samuel@dionne-riel.com>
Date: Mon, 6 Jan 2020 15:22:39 -0500
Subject: [PATCH] Adds (incomplete) system image build

This includes the proper kernel, but does nothing more.
---
 build.sh          | 13 +++++++++++++
 configuration.nix | 19 +++++++++++++++++++
 cross-hacks.nix   | 26 ++++++++++++++++++++++++++
 system.nix        |  7 +++++++
 with-cross.nix    | 11 +++++++++++
 5 files changed, 76 insertions(+)
 create mode 100755 build.sh
 create mode 100644 configuration.nix
 create mode 100644 cross-hacks.nix
 create mode 100644 system.nix
 create mode 100644 with-cross.nix

diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..4b19c01
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set -e
+set -u
+PS4=" $ "
+
+# Ugh, I would have liked to do it through a simpler `nix-build`, but  as this
+# needs to set `NIX_PATH` for use of `<nixpkgs/*>` imports, this is the better
+# way to go.
+
+set -x
+exec env -i NIX_PATH="nixpkgs=channel:nixos-19.09" nix-build \
+  system.nix -A config.system.build.sdImage "$@"
diff --git a/configuration.nix b/configuration.nix
new file mode 100644
index 0000000..c746eee
--- /dev/null
+++ b/configuration.nix
@@ -0,0 +1,19 @@
+{ config, pkgs, lib, ... }:
+{
+  imports = [
+    <nixpkgs/nixos/modules/installer/cd-dvd/sd-image-aarch64.nix>
+    <nixpkgs/nixos/modules/profiles/minimal.nix>
+    <nixpkgs/nixos/modules/profiles/installation-device.nix>
+    <nixpkgs/nixos/modules/installer/cd-dvd/sd-image.nix>
+  ];
+
+  nixpkgs.crossSystem = {
+    system = "aarch64-linux";
+  };
+
+  nixpkgs.overlays = [
+    (import ./overlay.nix)
+  ];
+
+  boot.kernelPackages = pkgs.linuxPackages-pinebookpro;
+}
diff --git a/cross-hacks.nix b/cross-hacks.nix
new file mode 100644
index 0000000..77fb3ad
--- /dev/null
+++ b/cross-hacks.nix
@@ -0,0 +1,26 @@
+# From this upstream repo:
+# https://github.com/samueldr/cross-system
+{ config, pkgs, lib, ... }:
+{
+
+  nixpkgs.overlays = [
+    (self: super: {
+      # Does not cross-compile...
+      alsa-firmware = pkgs.runCommandNoCC "neutered-firmware" {} "mkdir -p $out";
+    })
+  ];
+
+  # (Failing build in a dep to be investigated)
+  security.polkit.enable = false;
+
+  # cifs-utils fails to cross-compile
+  # Let's simplify this by removing all unneeded filesystems from the image.
+  boot.supportedFilesystems = lib.mkForce [ "vfat" ];
+
+  # texinfoInteractive has trouble cross-compiling
+  documentation.info.enable = lib.mkForce false;
+
+  # `xterm` is being included even though this is GUI-less.
+  # → https://github.com/NixOS/nixpkgs/pull/62852
+  services.xserver.desktopManager.xterm.enable = lib.mkForce false;
+}
diff --git a/system.nix b/system.nix
new file mode 100644
index 0000000..975a7b2
--- /dev/null
+++ b/system.nix
@@ -0,0 +1,7 @@
+import <nixpkgs/nixos> {
+  configuration =
+    if builtins.currentSystem == "aarch64-linux"
+    then builtins.toPath (./. + "/configuration.nix")
+    else builtins.toPath (./. + "/with-cross.nix")
+  ;
+}
diff --git a/with-cross.nix b/with-cross.nix
new file mode 100644
index 0000000..d0e44a3
--- /dev/null
+++ b/with-cross.nix
@@ -0,0 +1,11 @@
+{ config, pkgs, lib, ... }:
+{
+  imports = [
+    ./cross-hacks.nix
+    ./configuration.nix
+  ];
+
+  nixpkgs.crossSystem = {
+    system = "aarch64-linux";
+  };
+}