diff --git a/flake.nix b/flake.nix
index 615af54..512cd31 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,5 +1,5 @@
 {
-  description = "Zig Master Development Environment";
+  description = "Zig Host + Zig Xtensa (ESP32) Environment";
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
@@ -11,18 +11,44 @@
     let
       system = "x86_64-linux";
       pkgs = nixpkgs.legacyPackages.${system};
-      zig = zig-overlay.packages.${system}.master;
+      zig_host = zig-overlay.packages.${system}.master;
       zls = zls-overlay.packages.${system}.zls;
+
+      zig_xtensa = pkgs.stdenvNoCC.mkDerivation {
+        pname = "zig-xtensa";
+        version = "0.15.2";
+        src = pkgs.fetchzip {
+          url = "https://github.com/haivivi/embed-zig/releases/download/espressif-0.15.2/zig-x86_64-linux-gnu-baseline.tar.xz";
+          # Opraveny hash podla hlásenia Nixu
+          hash = "sha256-Wyc36nKM2PqljI4W8LsnEcVtrmchwQDoaUHAYOI0g1I=";
+          stripRoot = false;
+        };
+        dontBuild = true;
+        installPhase = ''
+          mkdir -p $out/bin
+          cp -r . $out/
+          # Symlink na binárku vo vnútri vnoreného adresára
+          ln -s $out/zig-x86_64-linux-gnu-baseline/zig $out/bin/zig-xtensa
+        '';
+      };
     in {
       devShells.${system}.default = pkgs.mkShell {
-        buildInputs = [ 
-	  zig 
-	  zls 
-	];
+        packages = [
+          zig_host
+          zls
+          zig_xtensa
+          pkgs.esptool
+          pkgs.espflash
+        ];
         shellHook = ''
-          echo "Entering Zig Master Environment"
-          echo "Zig: $(zig version)"
-          echo "ZLS: $(zls --version)"
+          echo ">>> Zig Master (host): $(zig version)"
+          echo ">>> Zig Xtensa (esp32): $(zig-xtensa version 2>/dev/null || echo 'Executable ready')"
+          
+          export PATH=$HOME/.rustup/toolchains/esp/xtensa-esp-elf/esp-14.2.0_20240906/xtensa-esp-elf/bin:$PATH
+          
+          if command -v xtensa-esp32-elf-gcc >/dev/null; then
+            echo ">>> Xtensa GCC: $(xtensa-esp32-elf-gcc --version | head -n 1)"
+          fi
         '';
       };
     };
diff --git a/test.o b/test.o
new file mode 100644
index 0000000..f5390bf
Binary files /dev/null and b/test.o differ
diff --git a/test.zig b/test.zig
new file mode 100644
index 0000000..2375171
--- /dev/null
+++ b/test.zig
@@ -0,0 +1,6 @@
+export fn main() void {
+    var i: u32 = 0;
+    while (i < 10) : (i += 1) {
+        asm volatile ("nop");
+    }
+}