something.md

❯ git diff older.nix newer.nix
diff --git a/older.nix b/newer.nix
index 71448f7..d2ba611 100644
--- a/older.nix
+++ b/newer.nix
@@ -2,12 +2,6 @@
 # nix-build nixos -I nixos-config=nixos/modules/installer/cd-dvd/sd-image-armv7l-multiplatform.nix -A config.system.build.sdImage
 { config, lib, pkgs, ... }:
 
-let
-  extlinux-conf-builder =
-    import ../../system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.nix {
-      pkgs = pkgs.buildPackages;
-    };
-in
 {
   imports = [
     ../../profiles/base.nix
@@ -29,7 +23,7 @@ in
   boot.kernelParams = ["console=ttyS0,115200n8" "console=ttymxc0,115200n8" "console=ttyAMA0,115200n8" "console=ttyO0,115200n8" "console=ttySAC2,115200n8" "console=tty0"];
 
   sdImage = {
-    populateBootCommands = let
+    populateFirmwareCommands = let
       configTxt = pkgs.writeText "config.txt" ''
         # Prevent the firmware from smashing the framebuffer setup done by the mainline kernel
         # when attempting to show low-voltage or overtemperature warnings.
@@ -46,11 +40,18 @@ in
         enable_uart=1
       '';
       in ''
-        (cd ${pkgs.raspberrypifw}/share/raspberrypi/boot && cp bootcode.bin fixup*.dat start*.elf $NIX_BUILD_TOP/boot/)
-        cp ${pkgs.ubootRaspberryPi2}/u-boot.bin boot/u-boot-rpi2.bin
-        cp ${pkgs.ubootRaspberryPi3_32bit}/u-boot.bin boot/u-boot-rpi3.bin
-        cp ${configTxt} boot/config.txt
-        ${extlinux-conf-builder} -t 3 -c ${config.system.build.toplevel} -d ./boot
+        (cd ${pkgs.raspberrypifw}/share/raspberrypi/boot && cp bootcode.bin fixup*.dat start*.elf $NIX_BUILD_TOP/firmware/)
+        cp ${pkgs.ubootRaspberryPi2}/u-boot.bin firmware/u-boot-rpi2.bin
+        cp ${pkgs.ubootRaspberryPi3_32bit}/u-boot.bin firmware/u-boot-rpi3.bin
+        cp ${configTxt} firmware/config.txt
       '';
+    populateRootCommands = ''
+      mkdir -p ./files/boot
+      ${config.boot.loader.generic-extlinux-compatible.populateCmd} -c ${config.system.build.toplevel} -d ./files/boot
+    '';
   };
+
+  # the installation media is also the installation target,
+  # so we don't want to provide the installation configuration.nix.
+  installer.cloneConfig = false;
 }