diff --git a/sdk/xtdk/amd64/mmtypes.h b/sdk/xtdk/amd64/mmtypes.h
index 6f91210..39b18fb 100644
--- a/sdk/xtdk/amd64/mmtypes.h
+++ b/sdk/xtdk/amd64/mmtypes.h
@@ -10,6 +10,7 @@
 #define __XTDK_AMD64_MMTYPES_H
 
 #include <xtbase.h>
+#include <mmtypes.h>
 
 
 /* Pages related definitions */
@@ -34,6 +35,9 @@
 /* Minimum number of physical pages needed by the system */
 #define MM_MINIMUM_PHYSICAL_PAGES                  2048
 
+/* Default number of secondary colors */
+#define MM_DEFAULT_SECONDARY_COLORS                64
+
 /* Page size enumeration list */
 typedef enum _PAGE_SIZE
 {
@@ -182,9 +186,51 @@ typedef union _MMPTE
     MMPTE_LIST List;
 } MMPTE, *PMMPTE;
 
-/* Page Directory Entry structure definitions */
-typedef union _MMPTE MMPDE, *PMMPDE;
-typedef union _MMPTE MMPPE, *PMMPPE;
-typedef union _MMPTE MMPXE, *PMMPXE;
+/* Page Frame Number structure definition */
+typedef struct _MMPFN
+{
+    union
+    {
+        PFN_NUMBER Flink;
+        ULONG WsIndex;
+        PKEVENT Event;
+        XTSTATUS ReadStatus;
+        SINGLE_LIST_ENTRY NextStackPfn;
+    } u1;
+    PMMPTE PteAddress;
+    union
+    {
+        PFN_NUMBER Blink;
+        ULONG_PTR ShareCount;
+    } u2;
+    union
+    {
+        MMPFNENTRY e1;
+        struct
+        {
+            USHORT ShortFlags;
+            USHORT ReferenceCount;
+        } e2;
+    } u3;
+    union
+    {
+        MMPTE OriginalPte;
+        LONG AweReferenceCount;
+    };
+    union
+    {
+        ULONG_PTR EntireFrame;
+        struct
+        {
+            ULONG_PTR PteFrame:58;
+            ULONG_PTR InPageError:1;
+            ULONG_PTR VerifierAllocation:1;
+            ULONG_PTR AweAllocation:1;
+            ULONG_PTR LockCharged:1;
+            ULONG_PTR KernelStack:1;
+            ULONG_PTR MustBeCached:1;
+        };
+    } u4;
+} MMPFN, *PMMPFN;
 
 #endif /* __XTDK_AMD64_MMTYPES_H */
diff --git a/sdk/xtdk/amd64/xtstruct.h b/sdk/xtdk/amd64/xtstruct.h
index ff1fcec..cee10a9 100644
--- a/sdk/xtdk/amd64/xtstruct.h
+++ b/sdk/xtdk/amd64/xtstruct.h
@@ -38,6 +38,7 @@ typedef struct _KSWITCH_FRAME KSWITCH_FRAME, *PKSWITCH_FRAME;
 typedef struct _KTHREAD_INIT_FRAME KTHREAD_INIT_FRAME, *PKTHREAD_INIT_FRAME;
 typedef struct _KTRAP_FRAME KTRAP_FRAME, *PKTRAP_FRAME;
 typedef struct _KTSS KTSS, *PKTSS;
+typedef struct _MMPFN MMPFN, *PMMPFN;
 typedef struct _MMPTE_HARDWARE MMPTE_HARDWARE, *PMMPTE_HARDWARE;
 typedef struct _MMPTE_HARDWARE_LARGEPAGE MMPTE_HARDWARE_LARGEPAGE, *PMMPTE_HARDWARE_LARGEPAGE;
 typedef struct _MMPTE_LIST MMPTE_LIST, *PMMPTE_LIST;
diff --git a/sdk/xtdk/i686/mmtypes.h b/sdk/xtdk/i686/mmtypes.h
index 2b1993f..3174ece 100644
--- a/sdk/xtdk/i686/mmtypes.h
+++ b/sdk/xtdk/i686/mmtypes.h
@@ -10,6 +10,7 @@
 #define __XTDK_I686_MMTYPES_H
 
 #include <xtbase.h>
+#include <mmtypes.h>
 
 
 /* Pages related definitions */
@@ -20,6 +21,9 @@
 /* Minimum number of physical pages needed by the system */
 #define MM_MINIMUM_PHYSICAL_PAGES                  1100
 
+/* Default number of secondary colors */
+#define MM_DEFAULT_SECONDARY_COLORS                64
+
 /* Page size enumeration list */
 typedef enum _PAGE_SIZE
 {
@@ -144,9 +148,6 @@ typedef union _MMPTE
     MMPTE_LIST List;
 } MMPTE, *PMMPTE;
 
-/* Page Directory Entry structure definition (with PAE support) */
-typedef union _MMPTE MMPDE, *PMMPDE;
-
 /* Legacy Page Table entry structure definition (without PAE support) */
 typedef struct _HARDWARE_LEGACY_PTE
 {
@@ -254,7 +255,51 @@ typedef union _MMPTE_LEGACY
     MMPTE_LEGACY_LIST List;
 } MMPTE_LEGACY, *PMMPTE_LEGACY;
 
-/* Page Directory Entry structure definition (without PAE support) */
-typedef union _MMPTE_LEGACY MMPDE_LEGACY, *PMMPDE_LEGACY;
+/* Page Frame Number structure definition */
+typedef struct _MMPFN
+{
+    union
+    {
+        PFN_NUMBER Flink;
+        ULONG WsIndex;
+        PKEVENT Event;
+        XTSTATUS ReadStatus;
+        SINGLE_LIST_ENTRY NextStackPfn;
+    } u1;
+    PMMPTE PteAddress;
+    union
+    {
+        PFN_NUMBER Blink;
+        ULONG_PTR ShareCount;
+    } u2;
+    union
+    {
+        MMPFNENTRY e1;
+        struct
+        {
+            USHORT ShortFlags;
+            USHORT ReferenceCount;
+        } e2;
+    } u3;
+    union
+    {
+        MMPTE OriginalPte;
+        LONG AweReferenceCount;
+    };
+    union
+    {
+        ULONG_PTR EntireFrame;
+        struct
+        {
+            ULONG_PTR PteFrame:26;
+            ULONG_PTR InPageError:1;
+            ULONG_PTR VerifierAllocation:1;
+            ULONG_PTR AweAllocation:1;
+            ULONG_PTR LockCharged:1;
+            ULONG_PTR KernelStack:1;
+            ULONG_PTR MustBeCached:1;
+        };
+    } u4;
+} MMPFN, *PMMPFN;
 
 #endif /* __XTDK_I686_MMTYPES_H */
diff --git a/sdk/xtdk/i686/xtstruct.h b/sdk/xtdk/i686/xtstruct.h
index 812ba7c..a690cc1 100644
--- a/sdk/xtdk/i686/xtstruct.h
+++ b/sdk/xtdk/i686/xtstruct.h
@@ -42,6 +42,7 @@ typedef struct _KSWITCH_FRAME KSWITCH_FRAME, *PKSWITCH_FRAME;
 typedef struct _KTHREAD_INIT_FRAME KTHREAD_INIT_FRAME, *PKTHREAD_INIT_FRAME;
 typedef struct _KTRAP_FRAME KTRAP_FRAME, *PKTRAP_FRAME;
 typedef struct _KTSS KTSS, *PKTSS;
+typedef struct _MMPFN MMPFN, *PMMPFN;
 typedef struct _MMPTE_HARDWARE MMPTE_HARDWARE, *PMMPTE_HARDWARE;
 typedef struct _MMPTE_LEGACY_HARDWARE MMPTE_LEGACY_HARDWARE, *PMMPTE_LEGACY_HARDWARE;
 typedef struct _MMPTE_LEGACY_LIST MMPTE_LEGACY_LIST, *PMMPTE_LEGACY_LIST;
diff --git a/sdk/xtdk/mmtypes.h b/sdk/xtdk/mmtypes.h
new file mode 100644
index 0000000..acbf7ed
--- /dev/null
+++ b/sdk/xtdk/mmtypes.h
@@ -0,0 +1,38 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            sdk/xtdk/mmtypes.h
+ * DESCRIPTION:     Memory management data structures
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#ifndef __XTDK_MMTYPES_H
+#define __XTDK_MMTYPES_H
+
+#include <xtbase.h>
+
+
+/* Color tables structure definition */
+typedef struct _MMCOLOR_TABLES
+{
+    ULONG_PTR Flink;
+    PVOID Blink;
+    ULONG_PTR Count;
+} MMCOLOR_TABLES, *PMMCOLOR_TABLES;
+
+/* Page Frame Entry structure definition */
+typedef struct _MMPFNENTRY
+{
+    USHORT Modified:1;
+    USHORT ReadInProgress:1;
+    USHORT WriteInProgress:1;
+    USHORT PrototypePte:1;
+    USHORT PageColor:4;
+    USHORT PageLocation:3;
+    USHORT RemovalRequested:1;
+    USHORT CacheAttribute:2;
+    USHORT Rom:1;
+    USHORT ParityError:1;
+} MMPFNENTRY, *PMMPFNENTRY;
+
+#endif /* __XTDK_MMTYPES_H */
diff --git a/sdk/xtdk/xtkmapi.h b/sdk/xtdk/xtkmapi.h
index 15813cd..86ba3a4 100644
--- a/sdk/xtdk/xtkmapi.h
+++ b/sdk/xtdk/xtkmapi.h
@@ -32,6 +32,7 @@
 #include <iotypes.h>
 #include <ketypes.h>
 #include <ldrtypes.h>
+#include <mmtypes.h>
 #include <potypes.h>
 #include <pstypes.h>
 #include <rtltypes.h>
diff --git a/sdk/xtdk/xtstruct.h b/sdk/xtdk/xtstruct.h
index 002db7e..fa7f9cd 100644
--- a/sdk/xtdk/xtstruct.h
+++ b/sdk/xtdk/xtstruct.h
@@ -243,6 +243,8 @@ typedef struct _LOADER_GRAPHICS_INFORMATION_BLOCK LOADER_GRAPHICS_INFORMATION_BL
 typedef struct _LOADER_INFORMATION_BLOCK LOADER_INFORMATION_BLOCK, *PLOADER_INFORMATION_BLOCK;
 typedef struct _LOADER_MEMORY_MAPPING LOADER_MEMORY_MAPPING, *PLOADER_MEMORY_MAPPING;
 typedef struct _M128 M128, *PM128;
+typedef struct _MMCOLOR_TABLES MMCOLOR_TABLES, *PMMCOLOR_TABLES;
+typedef struct _MMPFNENTRY MMPFNENTRY, *PMMPFNENTRY;
 typedef struct _PCAT_FIRMWARE_INFORMATION PCAT_FIRMWARE_INFORMATION, *PPCAT_FIRMWARE_INFORMATION;
 typedef struct _PCI_BRIDGE_CONTROL_REGISTER PCI_BRIDGE_CONTROL_REGISTER, *PPCI_BRIDGE_CONTROL_REGISTER;
 typedef struct _PCI_COMMON_CONFIG PCI_COMMON_CONFIG, *PPCI_COMMON_CONFIG;