From ca06f9ebb5fffe8ba08d4086d2887d3272fe4ea1 Mon Sep 17 00:00:00 2001
From: Aiken Harris <harraiken@noreply.codingworkshop.git>
Date: Sat, 2 Aug 2025 18:26:01 +0200
Subject: [PATCH] Correctly manage PAE state when enabling paging

---
 xtldr/modules/xtos_o/i686/memory.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/xtldr/modules/xtos_o/i686/memory.c b/xtldr/modules/xtos_o/i686/memory.c
index 9134a68..3dd8e31 100644
--- a/xtldr/modules/xtos_o/i686/memory.c
+++ b/xtldr/modules/xtos_o/i686/memory.c
@@ -125,8 +125,21 @@ XtEnablePaging(IN PXTBL_PAGE_MAPPING PageMap)
         return STATUS_EFI_ABORTED;
     }
 
-    /* Enable Physical Address Extension (PAE) */
-    ArWriteControlRegister(4, ArReadControlRegister(4) | CR4_PAE);
+    /* Disable paging */
+    ArWriteControlRegister(0, ArReadControlRegister(0) & ~CR0_PG);
+
+    if(PageMap->PageMapLevel == 3)
+    {
+        /* Enable Physical Address Extension (PAE) */
+        XtLdrProtocol->Debug.Print(L"Enabling Physical Address Extension (PAE)\n");
+        ArWriteControlRegister(4, ArReadControlRegister(4) | CR4_PAE);
+    }
+    else
+    {
+        /* Disable Physical Address Extension (PAE) */
+        XtLdrProtocol->Debug.Print(L"Disabling Physical Address Extension (PAE)\n");
+        ArWriteControlRegister(4, ArReadControlRegister(4) & ~CR4_PAE);
+    }
 
     /* Write page mappings to CR3 */
     ArWriteControlRegister(3, (UINT_PTR)PageMap->PtePointer);