From 7193e698f14d234996352a1d9d7afd3874a91491 Mon Sep 17 00:00:00 2001
From: Rafal Kupiec <belliash@codingworkshop.eu.org>
Date: Sun, 7 Apr 2024 17:49:24 +0200
Subject: [PATCH] Store page map level

---
 sdk/xtdk/xtfw.h             | 1 +
 xtldr/modules/xtos_o/xtos.c | 3 +++
 xtoskrnl/includes/globals.h | 3 +++
 xtoskrnl/mm/globals.c       | 3 +++
 xtoskrnl/mm/init.c          | 4 +++-
 5 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/sdk/xtdk/xtfw.h b/sdk/xtdk/xtfw.h
index b40be10..6470f82 100644
--- a/sdk/xtdk/xtfw.h
+++ b/sdk/xtdk/xtfw.h
@@ -108,6 +108,7 @@ typedef struct _LOADER_GRAPHICS_INFORMATION_BLOCK
 typedef struct _LOADER_INFORMATION_BLOCK
 {
     PVOID DbgPrint;
+    ULONG PageMapLevel;
     LOADER_GRAPHICS_INFORMATION_BLOCK FrameBuffer;
 } LOADER_INFORMATION_BLOCK, *PLOADER_INFORMATION_BLOCK;
 
diff --git a/xtldr/modules/xtos_o/xtos.c b/xtldr/modules/xtos_o/xtos.c
index c05e8e2..ceaab59 100644
--- a/xtldr/modules/xtos_o/xtos.c
+++ b/xtldr/modules/xtos_o/xtos.c
@@ -468,6 +468,9 @@ XtpInitializeLoaderBlock(IN PXTBL_PAGE_MAPPING PageMap,
         LoaderBlock->LoaderInformation.FrameBuffer.Initialized = FALSE;
     }
 
+    /* Store page map level */
+    LoaderBlock->LoaderInformation.PageMapLevel = 3;
+
     /* Close FrameBuffer protocol */
     XtLdrProtocol->Protocol.Close(ProtocolHandle, &FrameBufGuid);
 
diff --git a/xtoskrnl/includes/globals.h b/xtoskrnl/includes/globals.h
index dea6b0a..e6287e0 100644
--- a/xtoskrnl/includes/globals.h
+++ b/xtoskrnl/includes/globals.h
@@ -57,4 +57,7 @@ EXTERN ULONG MmNumberOfPhysicalPages;
 /* Old biggest free memory descriptor */
 EXTERN LOADER_MEMORY_MAPPING MmOldFreeDescriptor;
 
+/* Page Map Level */
+EXTERN ULONG MmPageMapLevel;
+
 #endif /* __XTOSKRNL_GLOBALS_H */
diff --git a/xtoskrnl/mm/globals.c b/xtoskrnl/mm/globals.c
index b2c75f6..0a7487f 100644
--- a/xtoskrnl/mm/globals.c
+++ b/xtoskrnl/mm/globals.c
@@ -23,3 +23,6 @@ ULONG MmNumberOfPhysicalPages;
 
 /* Old biggest free memory descriptor */
 LOADER_MEMORY_MAPPING MmOldFreeDescriptor;
+
+/* Page Map Level */
+ULONG MmPageMapLevel;
diff --git a/xtoskrnl/mm/init.c b/xtoskrnl/mm/init.c
index 5c85b22..6a51123 100644
--- a/xtoskrnl/mm/init.c
+++ b/xtoskrnl/mm/init.c
@@ -31,6 +31,9 @@ MmInitializeMemoryManager(VOID)
         KePanic(0);
     }
 
+    /* Store Page Map Level */
+    MmPageMapLevel = KeInitializationBlock->LoaderInformation.PageMapLevel;
+
     /* Proceed with architecture specific initialization */
     MmpInitializeArchitecture();
 }
@@ -108,7 +111,6 @@ MmpScanMemoryDescriptors(VOID)
 
     /* Store original free descriptor */
     RtlCopyMemory(&MmOldFreeDescriptor, MmFreeDescriptor, sizeof(LOADER_MEMORY_MAPPING));
-
 }
 
 /** Checks whether the specified memory type should be considered as free.