examples/demo: Use eval-with-configuration.nix

In addition, drop `android-burn-tool`. It hasn't been used for while, as
in the end it is not actually needed.

examples/demo/README.md

@@ -1,5 +1,7 @@
-> **WARNING**: This is still highly experimental. This is not usable as a daily
-> driver.
+> **WARNING**: This is not usable as a daily driver.
+
+This system is meant as *something* that is usable (barely) on mobile devices,
+while waiting for a more proper phone environment to be packaged.
 
 ## Building
 
@@ -8,29 +10,12 @@ armv7, aarch64 on aarch64).
 
 (Though the tooling will try to build it through cross-compilation!)
 
-> Note that this has been verified to work on `asus-z00t` on September 24th 2019,
-> using nixpkgs commit `d484f2b7fc0834a068e8ace851faa449a03963f5`.
-
-It should be possible to build both boot images via cross-compilation.
-
 ## Burning
 
-To burn the image, build the android-burn-tool, then fastboot it.
+This will differ depending on the device.
 
-```
-nix-build examples/demo/ --argstr device asus-flo -A android-burn-tool
-fastboot boot result
-```
-
-Once booting, it will show a yellow screen, then either a red or a green screen.
-The green screen means that it has found the expected partition to flash. A red
-screen means that the user will need to check what is up.
-
-The command will look like:
-
-```
-dd if=system.img bs=2M status=progress | bin/ssh-initrd dd of=/dev/[...] bs=2M
-```
+A common issue with android-based devices is the `system` partition being too
+small. To work around this issue, flash to `userdata`.
 
 ## Booting
 
@@ -41,4 +26,4 @@ The `boot.img` boot image is expecting to find the system partition using its
 label.
 
 It should also be possible to do this entirely statelessly by burning to an SD
-card, and fastboot booting the device.
+card, and using `fastboot boot`.

examples/demo/android-burn-tool.nix

@@ -1,46 +0,0 @@
-# This is intended to be used to produce a bootable `boot.img` with adbd, and
-# dropbear enabled. You would, in turn, use it to "flash" a dumb system.img file
-# to a partition, like userdata.
-#
-# *CAUTION* : there is no protection against flashing over the wrong partition.
-# Read about the usual pitfalls in the Android section of the documentation.
-{ config, lib, pkgs, ... }:
-
-let
-  device_info = config.mobile.device.info;
-in
-{
-  # Ensures we don't quit stage-1
-  mobile.boot.stage-1.shell.enable = true;
-  # Only enable `adb` if we know how to.
-  # FIXME: relies on implementation details. Poor separation of concerns.
-  mobile.adbd.enable = (config.mobile.system.type == "android") &&
-    (config.mobile.usb.mode != "gadgetfs" || config.mobile.usb.gadgetfs.functions ? ffs)
-  ;
-
-  # Enables networking and ssh in stage-1 !
-  mobile.boot.stage-1.networking.enable = true;
-  mobile.boot.stage-1.ssh.enable = true;
-  mobile.boot.stage-1.fbterm.enable = true;
-  mobile.boot.stage-1.tasks = [
-    (pkgs.writeText "adjust-brightness-task.rb" ''
-      class Tasks::AdjustBrightness < SingletonTask
-        def initialize()
-          add_dependency(:Target, :Environment)
-          add_dependency(:Target, :Graphics)
-        end
-
-        def run()
-          ["lcd-backlight", "wled"].each do |file|
-            # This can fail to write, ignore...
-            begin
-              max = File.read("/sys/class/leds/#{file}/max_brightness").to_i
-              System.write("/sys/class/leds/#{file}/brightness", (max * 0.1).to_i)
-            rescue
-            end
-          end
-        end
-      end
-    '')
-  ];
-}

examples/demo/default.nix

@@ -1,23 +1,11 @@
-{ device ? null }:
-let
-  system-build = import ../../. {
-    inherit device;
-    configuration = [ { imports = [ ./configuration.nix ]; } ];
-  };
-  burn-tool-build = import ../../. {
-    inherit device;
-    configuration = [ { imports = [ ./android-burn-tool.nix ]; } ];
-  };
-in
-  {
-    inherit (system-build) build;
-    inherit (system-build.build)
-      # Android devices
-      android-bootimg android-device
-      # QEMU VM
-      vm
-      # Depthcharge
-      disk-image
-    ;
-    android-burn-tool = burn-tool-build.build.android-bootimg;
-  }
+{ device ? null, pkgs ? null }@args:
+
+import ../../lib/eval-with-configuration.nix (args // {
+  configuration = [ (import ./configuration.nix) ];
+  additionalHelpInstructions = ''
+    You can build the `-A build.default` attribute to build the default output
+    for your device.
+
+     $ nix-build examples/demo --argstr device ${device} -A build.default
+  '';
+})