diff --git a/packages/zephyr/default.nix b/packages/zephyr/default.nix
index 6844833..0b4d7f5 100644
--- a/packages/zephyr/default.nix
+++ b/packages/zephyr/default.nix
@@ -11,4 +11,10 @@ in rec {
       inherit target sources;
       inherit (assets) version hosts;
     }) assets.toolchains;
+
+  sdk = callPackage ./sdk.nix {
+    inherit host-tools;
+    inherit (assets) version hosts;
+    source = assets.sdk;
+  };
 }
diff --git a/packages/zephyr/sdk.nix b/packages/zephyr/sdk.nix
new file mode 100644
index 0000000..43105cd
--- /dev/null
+++ b/packages/zephyr/sdk.nix
@@ -0,0 +1,21 @@
+{ lib, symlinkJoin, fetchurl, host-tools, source, version, hosts
+, toolchains ? [ ] }:
+let src = fetchurl source;
+in symlinkJoin rec {
+  pname = "zephyr-sdk";
+  inherit version;
+  name = "${pname}-${version}";
+
+  paths = [ host-tools ] ++ toolchains;
+  postBuild = ''
+    tar -C "$out" -xf "${src}" --exclude setup.sh --exclude sdk_toolchains --strip-components=1
+  '';
+
+  meta = with lib; {
+    homepage = "https://www.zephyrproject.org/";
+    description = "Full Zephyr SDK with customized toolchains";
+    license = licenses.asl20;
+    platforms = hosts;
+    maintainers = with maintainers; [ artemist ];
+  };
+}