From 269e9729701e8eb6ab3dd9d5cfdb9c2a7c38f01a Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Sun, 1 Oct 2023 22:13:51 +0100
Subject: [PATCH] use FIT images not appended DTB for aarch64 uimage

---
 pkgs/kernel/kernel_fdt.its | 50 ++++++++++++++++++++++++++++++++++++++
 pkgs/kernel/uimage.nix     | 12 ++++++---
 2 files changed, 59 insertions(+), 3 deletions(-)
 create mode 100644 pkgs/kernel/kernel_fdt.its

diff --git a/pkgs/kernel/kernel_fdt.its b/pkgs/kernel/kernel_fdt.its
new file mode 100644
index 0000000..9eba3d9
--- /dev/null
+++ b/pkgs/kernel/kernel_fdt.its
@@ -0,0 +1,50 @@
+/dts-v1/;
+
+//  used on aarch64 to provide a U-bootable image that combines
+//  kernel and fdt
+
+/ {
+    description = "Simple image with single Linux kernel and FDT blob";
+    #address-cells = <1>;
+
+    images {
+        kernel {
+            description = "Vanilla Linux kernel";
+            // data = /incbin/("./vmlinux.bin.gz");
+            type = "kernel";
+            arch = "arm64";
+            os = "linux";
+            // compression = "gzip";
+            // load = <00000000>;
+            // entry = <00000000>;
+            hash-1 {
+                    algo = "crc32";
+            };
+            hash-2 {
+                    algo = "sha1";
+            };
+	};
+        fdt-1 {
+            description = "Flattened Device Tree blob";
+            // data = /incbin/("./target.dtb");
+            type = "flat_dt";
+            arch = "arm64";
+            compression = "none";
+            hash-1 {
+                    algo = "crc32";
+            };
+            hash-2 {
+                    algo = "sha1";
+            };
+        };
+    };
+
+    configurations {
+        default = "conf-1";
+        conf-1 {
+            description = "Boot Linux kernel with FDT blob";
+            kernel = "kernel";
+            fdt = "fdt-1";
+        };
+    };
+};
diff --git a/pkgs/kernel/uimage.nix b/pkgs/kernel/uimage.nix
index d0882f8..a5c56fb 100644
--- a/pkgs/kernel/uimage.nix
+++ b/pkgs/kernel/uimage.nix
@@ -35,7 +35,6 @@ stdenv.mkDerivation {
     dtc -I dtb -O dts -o tmp.dts ${dtb}
     echo '/{ chosen { bootargs = ${builtins.toJSON commandLine}; }; };'  >> tmp.dts
     dtc -I dts -O dtb -o tmp.dtb tmp.dts
-	  ${objcopy} --update-section .appended_dtb=tmp.dtb vmlinux.elf || ${objcopy} --add-section .appended_dtb=${dtb} vmlinux.elf
   '';
 
   buildPhase =
@@ -51,9 +50,16 @@ stdenv.mkDerivation {
     in ''
       ${objcopy} -O binary -R .reginfo -R .notes -R .note -R .comment -R .mdebug -R .note.gnu.build-id -S vmlinux.elf vmlinux.bin
       rm -f vmlinux.bin.lzma ; lzma -k -z  vmlinux.bin
-      mkimage -A ${arch} -O linux -T kernel -C lzma -a ${loadAddress} -e ${entryPoint} -n '${lib.toUpper arch} Liminix Linux ${extraName}' -d vmlinux.bin.lzma kernel.uimage
+      cat ${./kernel_fdt.its} > mkimage.its
+      echo '/ { images { kernel { data = /incbin/("./vmlinux.bin.lzma"); }; }; };' >> mkimage.its
+      echo '/ { images { kernel { load = <${loadAddress}>; }; }; };' >> mkimage.its
+      echo '/ { images { kernel { entry = <${entryPoint}>; }; }; };' >> mkimage.its
+      echo '/ { images { kernel { compression = "lzma"; }; }; };' >> mkimage.its
+      echo '/ { images { fdt-1 { data = /incbin/("./tmp.dtb"); }; }; }; ' >> mkimage.its
+      mkimage -f mkimage.its mkimage.itb
+      mkimage -l mkimage.itb
     '';
   installPhase = ''
-    cp kernel.uimage $out
+    cp mkimage.itb $out
   '';
 }