diff --git a/src/xenia/base/memory_posix.cc b/src/xenia/base/memory_posix.cc
index 4098a3394b..2ff36a603d 100644
--- a/src/xenia/base/memory_posix.cc
+++ b/src/xenia/base/memory_posix.cc
@@ -85,11 +85,8 @@ void* AllocFixed(void* base_address, size_t length,
                  AllocationType allocation_type, PageAccess access) {
   // mmap does not support reserve / commit, so ignore allocation_type.
   uint32_t prot = ToPosixProtectFlags(access);
-  int flags = MAP_PRIVATE | MAP_ANONYMOUS;
-  if (base_address != nullptr) {
-    flags |= MAP_FIXED;
-  }
-  void* result = mmap(base_address, length, prot, flags, -1, 0);
+  void* result = mmap(base_address, length, prot,
+                      MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
   if (result == MAP_FAILED) {
     return nullptr;
   } else {
diff --git a/src/xenia/cpu/backend/x64/x64_backend.cc b/src/xenia/cpu/backend/x64/x64_backend.cc
index a567a4baaf..4b520b6b2a 100644
--- a/src/xenia/cpu/backend/x64/x64_backend.cc
+++ b/src/xenia/cpu/backend/x64/x64_backend.cc
@@ -480,9 +480,9 @@ HostToGuestThunk X64ThunkEmitter::EmitHostToGuestThunk() {
   code_offsets.prolog = getSize();
 
   // rsp + 0 = return address
-  mov(qword[rsp + 8 * 3], rdx);
-  mov(qword[rsp + 8 * 2], rsi);
-  mov(qword[rsp + 8 * 1], rdi);
+  // mov(qword[rsp + 8 * 3], rdx);
+  // mov(qword[rsp + 8 * 2], rsi);
+  // mov(qword[rsp + 8 * 1], rdi);
   sub(rsp, stack_size);
 
   code_offsets.prolog_stack_alloc = getSize();
@@ -501,9 +501,9 @@ HostToGuestThunk X64ThunkEmitter::EmitHostToGuestThunk() {
   code_offsets.epilog = getSize();
 
   add(rsp, stack_size);
-  mov(rdi, qword[rsp + 8 * 1]);
-  mov(rsi, qword[rsp + 8 * 2]);
-  mov(rdx, qword[rsp + 8 * 3]);
+  // mov(rdi, qword[rsp + 8 * 1]);
+  // mov(rsi, qword[rsp + 8 * 2]);
+  // mov(rdx, qword[rsp + 8 * 3]);
   ret();
 #else
   assert_always("Unknown platform ABI in host to guest thunk!");
diff --git a/src/xenia/vfs/devices/stfs_container_device.cc b/src/xenia/vfs/devices/stfs_container_device.cc
index 1381786322..2400da0e0c 100644
--- a/src/xenia/vfs/devices/stfs_container_device.cc
+++ b/src/xenia/vfs/devices/stfs_container_device.cc
@@ -17,33 +17,9 @@
 #include "xenia/base/math.h"
 #include "xenia/vfs/devices/stfs_container_entry.h"
 
-#if XE_PLATFORM_WIN32
-#include "xenia/base/platform_win.h"
-#define timegm _mkgmtime
-#endif
-
 namespace xe {
 namespace vfs {
 
-// Convert FAT timestamp to 100-nanosecond intervals since January 1, 1601 (UTC)
-uint64_t decode_fat_timestamp(uint32_t date, uint32_t time) {
-  struct tm tm = {0};
-  // 80 is the difference between 1980 (FAT) and 1900 (tm);
-  tm.tm_year = ((0xFE00 & date) >> 9) + 80;
-  tm.tm_mon = (0x01E0 & date) >> 5;
-  tm.tm_mday = (0x001F & date) >> 0;
-  tm.tm_hour = (0xF800 & time) >> 11;
-  tm.tm_min = (0x07E0 & time) >> 5;
-  tm.tm_sec = (0x001F & time) << 1;  // the value stored in 2-seconds intervals
-  tm.tm_isdst = 0;
-  time_t timet = timegm(&tm);
-  if (timet == -1) {
-    return 0;
-  }
-  // 11644473600LL is a difference between 1970 and 1601
-  return (timet + 11644473600LL) * 10000000;
-}
-
 StfsContainerDevice::StfsContainerDevice(const std::string_view mount_path,
                                          const std::filesystem::path& host_path)
     : Device(mount_path),
diff --git a/src/xenia/vfs/devices/stfs_xbox.h b/src/xenia/vfs/devices/stfs_xbox.h
index 0cba213937..54eaabb47c 100644
--- a/src/xenia/vfs/devices/stfs_xbox.h
+++ b/src/xenia/vfs/devices/stfs_xbox.h
@@ -10,12 +10,40 @@
 #ifndef XENIA_VFS_DEVICES_STFS_XBOX_H_
 #define XENIA_VFS_DEVICES_STFS_XBOX_H_
 
+#include <time.h>
+
+#include "xenia/xbox.h"
 #include "xenia/base/string_util.h"
 #include "xenia/kernel/util/xex2_info.h"
 
 namespace xe {
 namespace vfs {
 
+// Convert FAT timestamp to 100-nanosecond intervals since January 1, 1601 (UTC)
+inline uint64_t decode_fat_timestamp(const uint32_t date, const uint32_t time) {
+  struct tm tm = {0};
+  // 80 is the difference between 1980 (FAT) and 1900 (tm);
+  tm.tm_year = ((0xFE00 & date) >> 9) + 80;
+  tm.tm_mon = ((0x01E0 & date) >> 5) - 1;
+  tm.tm_mday = (0x001F & date) >> 0;
+  tm.tm_hour = (0xF800 & time) >> 11;
+  tm.tm_min = (0x07E0 & time) >> 5;
+  tm.tm_sec = (0x001F & time) << 1;  // the value stored in 2-seconds intervals
+  tm.tm_isdst = 0;
+
+#if XE_PLATFORM_WIN32
+  time_t timet = _mkgmtime(&tm);
+#else
+  time_t timet = timegm(&tm);
+#endif
+
+  if (timet == -1) {
+    return 0;
+  }
+  // 11644473600LL is a difference between 1970 and 1601
+  return (timet + 11644473600LL) * 10000000;
+}
+
 // Structs used for interchange between Xenia and actual Xbox360 kernel/XAM
 
 inline uint32_t load_uint24_be(const uint8_t* p) {
diff --git a/src/xenia/vfs/premake5.lua b/src/xenia/vfs/premake5.lua
index f312d93c6b..bd39df6f05 100644
--- a/src/xenia/vfs/premake5.lua
+++ b/src/xenia/vfs/premake5.lua
@@ -32,4 +32,5 @@ project("xenia-vfs-dump")
   resincludedirs({
     project_root,
   })
+include("testing")
 
diff --git a/src/xenia/vfs/testing/premake5.lua b/src/xenia/vfs/testing/premake5.lua
new file mode 100644
index 0000000000..d9cd89626f
--- /dev/null
+++ b/src/xenia/vfs/testing/premake5.lua
@@ -0,0 +1,8 @@
+project_root = "../../../.."
+include(project_root.."/tools/build")
+
+test_suite("xenia-vfs-tests", project_root, ".", {
+  links = {
+    "xenia-vfs",
+  },
+})
diff --git a/src/xenia/vfs/testing/vfs_test.cc b/src/xenia/vfs/testing/vfs_test.cc
new file mode 100644
index 0000000000..70a1c0f884
--- /dev/null
+++ b/src/xenia/vfs/testing/vfs_test.cc
@@ -0,0 +1,28 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2023 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/vfs/devices/stfs_xbox.h"
+
+#include "third_party/catch/include/catch.hpp"
+
+namespace xe::vfs::test {
+
+TEST_CASE("STFS Decode date and time", "[stfs_decode]") {
+  SECTION("10 June 2022 19:46:00 UTC - Decode") {
+    const uint16_t date = 0x54CA;
+    const uint16_t time = 0x9DBD;
+    const uint64_t result = 132993639580000000;
+
+    const uint64_t timestamp = decode_fat_timestamp(date, time);
+
+    REQUIRE(timestamp == result);
+  }
+}
+
+}  // namespace xe::vfs::test