From 29506a30ecf0083321810574e23052439cb33790 Mon Sep 17 00:00:00 2001
From: Cole Mickens <cole.mickens@gmail.com>
Date: Tue, 9 Jul 2024 13:22:54 -0700
Subject: [PATCH 1/2] system/kernel.nix: toplevel: add dtb link

---
 nixos/modules/system/boot/kernel.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/nixos/modules/system/boot/kernel.nix b/nixos/modules/system/boot/kernel.nix
index 4854119b25382..363f237880cc6 100644
--- a/nixos/modules/system/boot/kernel.nix
+++ b/nixos/modules/system/boot/kernel.nix
@@ -353,6 +353,14 @@ in
             ln -s ${config.system.build.initialRamdiskSecretAppender}/bin/append-initrd-secrets $out
 
             ln -s ${config.hardware.firmware}/lib/firmware $out/firmware
+
+            ${lib.optionalString (
+              config.hardware.deviceTree.enable
+              && config.hardware.deviceTree.package != null
+              && config.hardware.deviceTree.name != null)
+             # "ln -s ${config.boot.kernelPackages.package}/dtbs/${config.hardware.deviceTree.name} $out/dtb"
+             "ln -s ${config.hardware.deviceTree.package}/${config.hardware.deviceTree.name} $out/dtb"
+            }
           '';
 
         # Implement consoleLogLevel both in early boot and using sysctl

From 4f07523f641203388bb26fd7ea87ba7ffbfe9fb5 Mon Sep 17 00:00:00 2001
From: Cole Mickens <cole.mickens@gmail.com>
Date: Mon, 15 Jul 2024 23:23:11 -0700
Subject: [PATCH 2/2] systemd-boot-builder.py: add devicetree if dtb exists

---
 .../systemd-boot/systemd-boot-builder.py      | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py b/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py
index 87ea569bdb74e..7dd151f613228 100644
--- a/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py
+++ b/nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py
@@ -305,6 +305,29 @@ def write_entry(profile: str | None,
         sort_key=bootspec.sortKey,
         default=current
     ).write(sorted_first)
+ 
+    devicetree = None
+    dtb_link = f"{system_dir(profile, generation, specialisation)}/dtb"
+    if os.path.exists(dtb_link):
+        dtb_path = os.path.realpath(dtb_link)
+        if os.path.exists(dtb_path):
+            devicetree = copy_from_file(dtb_path)
+
+     with open(tmp_path, 'w') as f:
+         f.write(BOOT_ENTRY.format(title=title,
+                     sort_key=bootspec.sortKey,
+                     generation=generation,
+                     kernel=kernel,
+                     initrd=initrd,
+                     kernel_params=kernel_params,
+                     description=f"{bootspec.label}, built on {build_date}"))
+         if machine_id is not None:
+             f.write("machine-id %s\n" % machine_id)
+        if devicetree is not None:
+            f.write("devicetree %s\n" % devicetree)
+         f.flush()
+         os.fsync(f.fileno())
+     os.rename(tmp_path, entry_file)
 
 def get_generations(profile: str | None = None) -> list[SystemIdentifier]:
     gen_list = run(