From bbab6359b0a2fa8187c59f81f5c470c0d942fcc1 Mon Sep 17 00:00:00 2001
From: Duncan Ogilvie <mr.exodia.tpodt@gmail.com>
Date: Sat, 18 Sep 2021 22:45:29 +0200
Subject: [PATCH] Use KUSER_SHARED_DATA for checking the build number

---
 TitanEngine/TitanEngine.Debugger.DebugLoop.cpp | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/TitanEngine/TitanEngine.Debugger.DebugLoop.cpp b/TitanEngine/TitanEngine.Debugger.DebugLoop.cpp
index 3631fff..499104f 100644
--- a/TitanEngine/TitanEngine.Debugger.DebugLoop.cpp
+++ b/TitanEngine/TitanEngine.Debugger.DebugLoop.cpp
@@ -57,17 +57,11 @@ __declspec(dllexport) void TITCALL DebugLoop()
     bool IsDbgReplyLaterSupported = false;
     
     // Check if DBG_REPLY_LATER is supported based on Windows version (Windows 10, version 1507 or above)
-    OSVERSIONINFOEXA OSInfo;
-    OSInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEXA);
-
-    if (GetVersionExA((LPOSVERSIONINFOA)&OSInfo))
+    // https://www.gaijin.at/en/infos/windows-version-numbers
+    const uint32_t NtBuildNumber = *(uint32_t*)(0x7FFE0000 + 0x260);
+    if (NtBuildNumber != 0 && NtBuildNumber >= 10240)
     {
-        if (OSInfo.wProductType == VER_NT_WORKSTATION &&
-            (OSInfo.dwMajorVersion > 10 || 
-            (OSInfo.dwMajorVersion == 10 && OSInfo.dwBuildNumber >= 1507)))
-        {
-            IsDbgReplyLaterSupported = true;
-        }
+        IsDbgReplyLaterSupported = true;
     }
 
     DBGFileHandle = NULL;