diff --git a/BUILD.gn b/BUILD.gn
index 6fd871945..10c483c54 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -36,9 +36,7 @@ if (is_win) {
 }
 
 config("vulkan_internal_config") {
-  defines = [
-    "VK_ENABLE_BETA_EXTENSIONS",
-  ]
+  defines = [ "VK_ENABLE_BETA_EXTENSIONS" ]
   if (is_clang || !is_win) {
     cflags = [
       "-Wno-conversion",
@@ -99,6 +97,52 @@ if (!is_android) {
   } else {
     library_type = "static_library"
   }
+  support_unknown_function_handling = false
+  if (ar_path != "" && !is_win && (current_cpu == "arm64" || current_cpu == "x86_64")) {
+    support_unknown_function_handling = true
+    static_library("asm_offset") {
+      sources = [ "loader/asm_offset.c" ]
+      deps = [
+        "$vulkan_headers_dir:vulkan_headers",
+      ]
+
+      if (is_fuchsia) {
+        deps += [
+          ":dlopen_fuchsia",
+        ]
+      }
+
+      # Output raw assembly instead of compiled object file. The assembly will be included as a member of the output ar file.
+      cflags = [ "-S" ]
+      configs += [ ":vulkan_internal_config" ]
+      configs += [ ":vulkan_loader_config" ]
+    }
+
+    action("gen_defines") {
+      script = "scripts/parse_asm_values.py"
+      deps = [ ":asm_offset" ]
+
+      inputs = [
+        "$target_out_dir/libasm_offset.a",
+        ar_path,
+      ]
+      if (current_cpu == "arm64") {
+        cpu = "aarch64"
+      } else {
+        cpu = "x86_64"
+      }
+      args = [
+        rebase_path("$target_gen_dir/gen_defines.asm", root_build_dir),
+        rebase_path("$target_out_dir/libasm_offset.a", root_build_dir),
+        "GAS",
+        "Clang",
+        cpu,
+        rebase_path(ar_path, root_build_dir),
+        "libasm_offset.asm_offset.c.o",
+      ]
+      outputs = [ "$target_gen_dir/gen_defines.asm" ]
+    }
+  }
 
   target(library_type, "libvulkan") {
     sources = [
@@ -135,8 +179,6 @@ if (!is_android) {
       "loader/unknown_function_handling.h",
       "loader/unknown_function_handling.c",
       "loader/vk_loader_layer.h",
-
-      # TODO(jmadill): Use assembler where available.
       "loader/vk_loader_platform.h",
       "loader/wsi.c",
       "loader/wsi.h",
@@ -217,6 +259,19 @@ if (!is_android) {
 
       runtime_deps = [ "//sdk/lib/fdio:fdio_sdk" ]
     }
+    if (support_unknown_function_handling) {
+      if (current_cpu == "arm64") {
+        sources += [ "loader/unknown_ext_chain_gas_aarch.S" ]
+      } else if (current_cpu == "x86_64") {
+        sources += [ "loader/unknown_ext_chain_gas_x86.S" ]
+      } else {
+        assert(false, "Unexpected CPU $current_cpu")
+      }
+
+      defines += ["UNKNOWN_FUNCTIONS_SUPPORTED=1"]
+      deps += [ ":gen_defines" ]
+      include_dirs = [ "$target_gen_dir" ]
+    }
   }
 }
 
diff --git a/loader/unknown_ext_chain_gas_aarch.S b/loader/unknown_ext_chain_gas_aarch.S
index 1176be30f..a78a32d34 100644
--- a/loader/unknown_ext_chain_gas_aarch.S
+++ b/loader/unknown_ext_chain_gas_aarch.S
@@ -24,7 +24,7 @@
 // VkPhysicalDevice or a dispatchable object it can unwrap the object, possibly overwriting the wrapped physical device, and then
 // jump to the next function in the call chain
 
-.include "gen_defines.asm"
+#include "gen_defines.asm"
 
 /*
  * References:
@@ -56,6 +56,7 @@
 .macro PhysDevExtTramp num
 .global vkPhysDevExtTramp\num
 #if defined(__ELF__)
+ .type vkPhysDevExtTramp\num, @function
  .hidden vkPhysDevExtTramp\num
 #endif
 .balign 4
@@ -77,6 +78,7 @@ vkPhysDevExtTramp\num:
 .macro PhysDevExtTermin num
 .global vkPhysDevExtTermin\num
 #if defined(__ELF__)
+ .type vkPhysDevExtTermin\num, @function
  .hidden vkPhysDevExtTermin\num
 #endif
 .balign 4
diff --git a/loader/unknown_ext_chain_gas_x86.S b/loader/unknown_ext_chain_gas_x86.S
index de5a92030..5ee020512 100644
--- a/loader/unknown_ext_chain_gas_x86.S
+++ b/loader/unknown_ext_chain_gas_x86.S
@@ -33,7 +33,7 @@
 #endif
 
 .intel_syntax noprefix
-.include "gen_defines.asm"
+#include "gen_defines.asm"
 
 .ifdef X86_64
 
diff --git a/scripts/gn/secondary/build_overrides/vulkan_loader.gni b/scripts/gn/secondary/build_overrides/vulkan_loader.gni
index c826fc112..4cf8e8279 100644
--- a/scripts/gn/secondary/build_overrides/vulkan_loader.gni
+++ b/scripts/gn/secondary/build_overrides/vulkan_loader.gni
@@ -21,3 +21,5 @@ vulkan_gen_subdir = ""
 # Vulkan loader build options
 vulkan_loader_shared = true
 
+# Path to ar or llvm-ar
+ar_path = ""
diff --git a/scripts/parse_asm_values.py b/scripts/parse_asm_values.py
index cab5ef9dc..172a36339 100644
--- a/scripts/parse_asm_values.py
+++ b/scripts/parse_asm_values.py
@@ -25,6 +25,8 @@
 import os.path
 from os.path import exists
 import re
+import subprocess
+import traceback
 
 
 # Where to write the "gen_defines.asm" file
@@ -57,12 +59,23 @@
             "DISPATCH_OFFSET_ICD_TERM",
             "EXT_OFFSET_DEVICE_DISPATCH" ]
 
-try:
-    with open(source_asm_file, 'r') as f:
-        asm_intermediate_file = f.read()
-except IOError:
-    print("Could not open assembler file:", source_asm_file)
-    sys.exit(1)
+if os.path.splitext(source_asm_file)[1] == ".a":
+    try:
+        ar_path = sys.argv[6]
+        asm_archive_member = sys.argv[7]
+        subprocess_result = subprocess.Popen([ar_path, "p", source_asm_file, asm_archive_member], stdout=subprocess.PIPE)
+        asm_intermediate_file = subprocess_result.stdout.read().decode("utf-8")
+    except IOError:
+        print("Could not open assembler archive file:", source_asm_file)
+        traceback.print_exc()
+        sys.exit(1)
+else:
+    try:
+        with open(source_asm_file, 'r') as f:
+            asm_intermediate_file = f.read()
+    except IOError:
+        print("Could not open assembler file:", source_asm_file)
+        sys.exit(1)
 
 with open(destination_file, "w", encoding="utf-8") as dest:
     if assembler_type == "MASM":