From de2973ac42bedea5c17e87f49cc5f3993bb4e515 Mon Sep 17 00:00:00 2001
From: Aiken Harris <harraiken91@gmail.com>
Date: Sat, 16 Aug 2025 20:28:05 +0200
Subject: [PATCH] Implement page map info initialization

---
 xtoskrnl/mm/amd64/init.c | 26 +++++++++++++++++++++++++-
 xtoskrnl/mm/i686/init.c  | 28 +++++++++++++++++++++++++++-
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/xtoskrnl/mm/amd64/init.c b/xtoskrnl/mm/amd64/init.c
index 88e27d7..0b930ef 100644
--- a/xtoskrnl/mm/amd64/init.c
+++ b/xtoskrnl/mm/amd64/init.c
@@ -20,7 +20,31 @@ XTAPI
 VOID
 MmInitializePageMapSupport(VOID)
 {
-    UNIMPLEMENTED;
+    /* Check if XPA is enabled */
+    if(MmpGetExtendedPhysicalAddressingStatus())
+    {
+        /* Set PML5 page map information */
+        MmpPageMapInfo.Xpa = TRUE;
+
+        /* Set PML5 base addresses */
+        MmpPageMapInfo.PteBase = MM_PTE_LA57_BASE;
+        MmpPageMapInfo.PdeBase = MM_PDE_LA57_BASE;
+        MmpPageMapInfo.PpeBase = MM_PPE_LA57_BASE;
+        MmpPageMapInfo.PxeBase = MM_PXE_LA57_BASE;
+        MmpPageMapInfo.P5eBase = MM_P5E_LA57_BASE;
+    }
+    else
+    {
+        /* Set PML4 page map information */
+        MmpPageMapInfo.Xpa = FALSE;
+
+        /* Set PML4 base addresses */
+        MmpPageMapInfo.PteBase = MM_PTE_BASE;
+        MmpPageMapInfo.PdeBase = MM_PDE_BASE;
+        MmpPageMapInfo.PpeBase = MM_PPE_BASE;
+        MmpPageMapInfo.PxeBase = MM_PXE_BASE;
+        MmpPageMapInfo.P5eBase = 0x0;
+    }
 }
 
 /**
diff --git a/xtoskrnl/mm/i686/init.c b/xtoskrnl/mm/i686/init.c
index fe4887e..8a8a9ce 100644
--- a/xtoskrnl/mm/i686/init.c
+++ b/xtoskrnl/mm/i686/init.c
@@ -20,7 +20,33 @@ XTAPI
 VOID
 MmInitializePageMapSupport(VOID)
 {
-    UNIMPLEMENTED;
+    /* Check if XPA is enabled */
+    if(MmpGetExtendedPhysicalAddressingStatus())
+    {
+        /* Set PML3 page map information */
+        MmpPageMapInfo.Xpa = TRUE;
+
+        /* Set PML3 base addresses */
+        MmpPageMapInfo.PteBase = MM_PTE_BASE;
+        MmpPageMapInfo.PdeBase = MM_PDE_BASE;
+
+        /* Set PML3 shift values */
+        MmpPageMapInfo.PdiShift = MM_PDI_SHIFT;
+        MmpPageMapInfo.PteShift = MM_PTE_SHIFT;
+    }
+    else
+    {
+        /* Set PML2 page map information */
+        MmpPageMapInfo.Xpa = FALSE;
+
+        /* Set PML2 base addresses */
+        MmpPageMapInfo.PteBase = MM_PTE_BASE;
+        MmpPageMapInfo.PdeBase = MM_PDE_LEGACY_BASE;
+
+        /* Set PML2 shift values */
+        MmpPageMapInfo.PdiShift = MM_PDI_LEGACY_SHIFT;
+        MmpPageMapInfo.PteShift = MM_PTE_LEGACY_SHIFT;
+    }
 }
 
 /**