diff --git a/deps/ReactantExtra/BUILD b/deps/ReactantExtra/BUILD
index 441e43b8..75ae01a1 100644
--- a/deps/ReactantExtra/BUILD
+++ b/deps/ReactantExtra/BUILD
@@ -1,5 +1,6 @@
 load("@llvm-project//mlir:tblgen.bzl", "gentbl_cc_library", "td_library")
 load("@xla//tools/toolchains/cross_compile/cc:cc_toolchain_config.bzl", "cc_toolchain_config")
+# load("//toolchain:yggdrasil.bzl", "ygg_cc_toolchain")
 licenses(["notice"])
 
 package(
diff --git a/deps/ReactantExtra/toolchain/yggdrasil.bzl b/deps/ReactantExtra/toolchain/yggdrasil.bzl
new file mode 100644
index 00000000..5ead0330
--- /dev/null
+++ b/deps/ReactantExtra/toolchain/yggdrasil.bzl
@@ -0,0 +1,117 @@
+load("@rules_cc//cc:defs.bzl", "cc_toolchain")
+load("@xla//tools/toolchains/cross_compile/cc:cc_toolchain_config.bzl", "cc_toolchain_config")
+
+# name = "ygg_aarch64_toolchain_config"
+# cpu = "aarch64"
+# toolchain_identifier = "ygg_aarch64"
+# target_system_name = "aarch64-unknown-linux-gnu"
+def ygg_cc_toolchain(cpu, toolchain_identifier, target_system_name, bb_target, bb_full_target, supports_start_end_lib = False):
+    cc_toolchain(
+        name = "ygg_target_toolchain",
+        all_files = ":empty",
+        compiler_files = ":empty",
+        dwp_files = ":empty",
+        linker_files = ":empty",
+        objcopy_files = ":empty",
+        strip_files = ":empty",
+        supports_param_files = 1,
+        toolchain_config = ":ygg_target_toolchain_config",
+        toolchain_identifier = "ygg_toolchain",
+    )
+
+    # TODO distinguish between clang and gcc toolchains?
+    cc_toolchain_config(
+        name = "ygg_target_toolchain_config",
+        cpu = cpu,
+        compiler = "compiler",
+        toolchain_identifier = toolchain_identifier,
+        target_system_name = target_system_name,
+        target_libc = "",
+        abi_libc_version = "local",
+        abi_version = "local",
+        cxx_builtin_include_directories = [
+            f"/opt/{bb_target}/lib/gcc/{bb_target}/10.2.0/include",
+            f"/opt/{bb_target}/lib/gcc/{bb_target}/10.2.0/include-fixed",
+            f"/opt/{bb_target}/{bb_target}/include",
+            f"/opt/{bb_target}/{bb_target}/sys-root/usr/include",
+            f"/opt/{bb_target}/{bb_target}/include/c++/10.2.0",
+            f"/opt/{bb_target}/{bb_target}/include/c++/10.2.0/{bb_target}",
+            f"/opt/{bb_target}/{bb_target}/include/c++/10.2.0/backward",
+            f"/opt/{bb_target}/{bb_target}/include/c++/10.2.0/parallel"
+        ],
+        tool_paths = {
+            "ar": f"/opt/bin/{bb_full_target}/ar",
+            "as": f"/opt/bin/{bb_full_target}/as",
+            "c++": f"/opt/bin/{bb_full_target}/c++",
+            "c++filt": f"/opt/bin/{bb_full_target}/c++filt",
+            "cc": f"/opt/bin/{bb_full_target}/cc",
+            "clang": f"/opt/bin/{bb_full_target}/clang",
+            "clang++": f"/opt/bin/{bb_full_target}/clang++",
+            "cpp": f"/opt/bin/{bb_full_target}/cpp",
+            "f77": f"/opt/bin/{bb_full_target}/f77",
+            "g++": f"/opt/bin/{bb_full_target}/g++",
+            "gcc": f"/opt/bin/{bb_full_target}/gcc",
+            "gfortran": f"/opt/bin/{bb_full_target}/gfortran",
+            "ld": f"/opt/bin/{bb_full_target}/ld",
+            "ld.lld": f"/opt/bin/{bb_full_target}/ld.lld",
+            "libtool": f"/opt/bin/{bb_full_target}/libtool",
+            "lld": f"/opt/bin/{bb_full_target}/lld",
+            "nm": f"/opt/bin/{bb_full_target}/nm",
+            "objcopy": f"/opt/bin/{bb_full_target}/objcopy",
+            "patchelf": f"/opt/bin/{bb_full_target}/patchelf",
+            "ranlib": f"/opt/bin/{bb_full_target}/ranlib",
+            "readelf": f"/opt/bin/{bb_full_target}/readelf",
+            "strip": f"/opt/bin/{bb_full_target}/strip",
+            # from host
+            "llvm-cov": "/opt/x86_64-linux-musl/bin/llvm-cov",
+            "llvm-profdata": "/opt/x86_64-linux-musl/bin/llvm-profdata",
+            "objdump": "/usr/bin/objdump",
+        },
+        compile_flags = [
+            "-fstack-protector",
+            "-Wall",
+            "-Wunused-but-set-parameter",
+            "-Wno-free-nonheap-object",
+            "-fno-omit-frame-pointer",
+            # TODO cxx_builtin_include_directories doesn't seem to be working, so we add the INCLUDE_PATHs manually
+            f"-isystem /opt/{bb_target}/lib/gcc/{bb_target}/10.2.0/include",
+            f"-isystem /opt/{bb_target}/lib/gcc/{bb_target}/10.2.0/include-fixed",
+            f"-isystem /opt/{bb_target}/{bb_target}/include",
+            f"-isystem /opt/{bb_target}/{bb_target}/sys-root/usr/include",
+            f"-isystem /opt/{bb_target}/{bb_target}/include/c++/10.2.0",
+            f"-isystem /opt/{bb_target}/{bb_target}/include/c++/10.2.0/{bb_target}",
+            f"-isystem /opt/{bb_target}/{bb_target}/include/c++/10.2.0/backward",
+            f"-isystem /opt/{bb_target}/{bb_target}/include/c++/10.2.0/parallel",
+        ],
+        opt_compile_flags = [
+            "-g0",
+            "-O2",
+            "-D_FORTIFY_SOURCE=1",
+            "-DNDEBUG",
+            "-ffunction-sections",
+            "-fdata-sections",
+            # "-stdlib=libstdc++",
+        ],
+        dbg_compile_flags = ["-g"],
+        link_flags = [],
+        link_libs = [
+            "-lstdc++",
+            "-lm",
+        ],
+        opt_link_flags = ["-Wl,--gc-sections"],
+        unfiltered_compile_flags = [
+            "-no-canonical-prefixes",
+            "-Wno-builtin-macro-redefined",
+            "-D__DATE__=\"redacted\"",
+            "-D__TIMESTAMP__=\"redacted\"",
+            "-D__TIME__=\"redacted\"",
+            "-Wno-unused-command-line-argument",
+            "-Wno-gnu-offsetof-extensions",
+        ],
+        builtin_sysroot = f"/opt/{bb_target}/{bb_target}/sys-root/",
+        coverage_compile_flags = ["--coverage"],
+        coverage_link_flags = ["--coverage"],
+        host_system_name = "linux",
+        # TODO gcc doesn't support it, only put it on clang (maybe even only for clang on aarch64-darwin?)
+        supports_start_end_lib = supports_start_end_lib,
+    )