diff --git a/derivations.nix b/derivations.nix
index e966764..327b676 100644
--- a/derivations.nix
+++ b/derivations.nix
@@ -1,9 +1,12 @@
 { pkgs }:
-rec {
+let
+  llvm-src = pkgs.callPackage ./fetch-llvm-clang.nix {};
+in rec {
   yosys = pkgs.callPackage ./yosys.nix {};
   symbiyosys = pkgs.symbiyosys.override { inherit yosys; };
   nmigen = pkgs.callPackage ./nmigen.nix { inherit yosys; };
   jtagtap = pkgs.callPackage ./jtagtap.nix { inherit nmigen; };
   minerva = pkgs.callPackage ./minerva.nix { inherit nmigen; inherit jtagtap; };
   heavycomps = pkgs.callPackage ./heavycomps.nix { inherit nmigen; };
+  llvm-hx = pkgs.callPackage ./llvm-hx.nix { inherit llvm-src; };
 }
diff --git a/fetch-llvm-clang.nix b/fetch-llvm-clang.nix
new file mode 100644
index 0000000..686aef9
--- /dev/null
+++ b/fetch-llvm-clang.nix
@@ -0,0 +1,22 @@
+{ runCommand, fetchFromGitHub, git }:
+
+let
+llvm-src = fetchFromGitHub {
+  rev = "527aa86b578da5dfb9cf4510b71f0f46a11249f7";
+  owner = "m-labs";
+  repo = "llvm-or1k";
+  sha256 = "0lmcg9xj66pf4mb6racipw67vm8kwm84dl861hyqnywd61kvhrwa";
+};
+clang-src = fetchFromGitHub {
+  rev = "9e996136d52ed506ed8f57ef8b13b0f0f735e6a3";
+  owner = "m-labs";
+  repo = "clang-or1k";
+  sha256 = "0w5f450i76y162aswi2c7jip8x3arzljaxhbqp8qfdffm0rdbjp4";
+};
+in
+runCommand "llvm_or1k_src" {}''
+mkdir -p $out
+mkdir -p $out/tools/clang
+cp -r ${llvm-src}/* $out/
+cp -r ${clang-src}/* $out/tools/clang
+''
diff --git a/llvm-hx.nix b/llvm-hx.nix
new file mode 100644
index 0000000..c287f99
--- /dev/null
+++ b/llvm-hx.nix
@@ -0,0 +1,45 @@
+{ stdenv
+, git
+, llvm-src
+,  perl, groff, cmake, libxml2, python, libffi, valgrind
+, ...
+}:
+
+stdenv.mkDerivation rec {
+  name = "llvm-hx";
+  src = llvm-src;
+
+ buildInputs = [ perl groff cmake libxml2 python libffi ] ++ stdenv.lib.optional stdenv.isLinux valgrind;
+
+  preBuild = ''
+    NIX_BUILD_CORES=4
+    makeFlagsArray=(-j''$NIX_BUILD_CORES)
+    mkdir -p $out/
+  '';
+
+  cmakeFlags = with stdenv; [
+    "-DCMAKE_BUILD_TYPE=Release"
+    "-DLLVM_BUILD_LLVM_DYLIB=ON"
+    "-DLLVM_LINK_LLVM_DYLIB=ON"
+    "-DLLVM_TARGETS_TO_BUILD=X86"
+    "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=RISCV;OR1K"
+    "-DLLVM_ENABLE_ASSERTIONS=OFF"
+    "-DLLVM_INSTALL_UTILS=ON"
+    "-DLLVM_INCLUDE_TESTS=OFF"
+    "-DLLVM_INCLUDE_DOCS=OFF"
+    "-DLLVM_INCLUDE_EXAMPLES=OFF"
+    "-DCLANG_ENABLE_ARCMT=OFF"
+    "-DCLANG_ENABLE_STATIC_ANALYZER=OFF"
+    "-DCLANG_INCLUDE_TESTS=OFF"
+    "-DCLANG_INCLUDE_DOCS=OFF"
+  ];
+
+  enableParallelBuilding = true;
+  meta = {
+    description = "Collection of modular and reusable compiler and toolchain technologies";
+    homepage = http://llvm.org/;
+    license = stdenv.lib.licenses.bsd3;
+    maintainers = with stdenv.lib.maintainers; [ sb0 ];
+    platforms = stdenv.lib.platforms.all;
+  };
+}