diff --git a/kernel/trunk/const.inc b/kernel/trunk/const.inc
index 78403f394d..20d25d89b0 100644
--- a/kernel/trunk/const.inc
+++ b/kernel/trunk/const.inc
@@ -1,6 +1,6 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;                                                              ;;
-;; Copyright (C) KolibriOS team 2004-2014. All rights reserved. ;;
+;; Copyright (C) KolibriOS team 2004-2015. All rights reserved. ;;
 ;; Distributed under terms of the GNU General Public License    ;;
 ;;                                                              ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -98,6 +98,9 @@ CAPS_ALTMOVCR8 equ    74 ;
 MSR_SYSENTER_CS         equ     0x174
 MSR_SYSENTER_ESP        equ     0x175
 MSR_SYSENTER_EIP        equ     0x176
+MSR_CR_PAT              equ     0x277
+MSR_MTRR_DEF_TYPE       equ     0x2FF
+
 MSR_AMD_EFER            equ     0xC0000080      ; Extended Feature Enable Register
 MSR_AMD_STAR            equ     0xC0000081      ; SYSCALL/SYSRET Target Address Register
 
@@ -276,7 +279,9 @@ PG_WRITE            equ 0x002
 PG_USER             equ 0x004
 PG_PCD              equ 0x008
 PG_PWT              equ 0x010
-
+PG_ACCESSED         equ 0x020
+PG_DIRTY            equ 0x040
+PG_PAT              equ 0x080
 PG_GLOBAL           equ 0x100
 PG_SHARED           equ 0x200
 
@@ -287,6 +292,18 @@ PG_NOCACHE          equ 0x018 ; (PG_PCD+PG_PWT)
 
 PDE_LARGE           equ 0x080
 
+PAT_WB              equ 0x000
+PAT_WC              equ 0x008
+PAT_UCM             equ 0x010
+PAT_UC              equ 0x018
+
+PAT_TYPE_UC         equ 0
+PAT_TYPE_WC         equ 1
+PAT_TYPE_WB         equ 6
+PAT_TYPE_UCM        equ 7
+
+PAT_VALUE           equ 0x00070106; (UC<<24)|(UCM<<16)|(WC<<8)|WB
+
 ;;;;;;;;;;;boot time variables
 
 BOOT_BPP            equ 0x9000    ;byte   bits per pixel
diff --git a/kernel/trunk/core/mtrr.inc b/kernel/trunk/core/mtrr.inc
index 8d7c2bdf6e..607b803cd4 100644
--- a/kernel/trunk/core/mtrr.inc
+++ b/kernel/trunk/core/mtrr.inc
@@ -25,21 +25,65 @@ endp
 
 ; Helper procedure for mtrr_reconfigure and set_mtrr,
 ; called before changes in MTRRs.
+; 1. disable and flush caches
+; 2. clear PGE bit in cr4
+; 3. flush TLB
+; 4. disable mtrr
+
 proc mtrr_begin_change
         mov     eax, cr0
         or      eax, 0x60000000 ;disable caching
         mov     cr0, eax
         wbinvd                  ;invalidate cache
+
+        bt      [cpu_caps], CAPS_PGE
+        jnc     .cr3_flush
+
+        mov     eax, cr4
+        btr     eax, 7          ;clear cr4.PGE
+        mov     cr4, eax        ;flush TLB
+        jmp     @F              ;skip extra serialization
+
+.cr3_flush:
+        mov     eax, cr3
+        mov     cr3, eax        ;flush TLB
+@@:
+        mov     ecx, MSR_MTRR_DEF_TYPE
+        rdmsr
+        btr     eax, 11         ;clear enable flag
+        wrmsr                   ;disable mtrr
         ret
 endp
 
 ; Helper procedure for mtrr_reconfigure and set_mtrr,
 ; called after changes in MTRRs.
+; 1. enable mtrr
+; 2. flush all caches
+; 3. flush TLB
+; 4. restore cr4.PGE flag, if required
+
 proc mtrr_end_change
+        mov     ecx, MSR_MTRR_DEF_TYPE
+        rdmsr
+        or      ah, 8           ; enable variable-ranges MTRR
+        and     al, 0xF0        ; default memtype = UC
+        wrmsr
+
         wbinvd                  ;again invalidate
         mov     eax, cr0
         and     eax, not 0x60000000
         mov     cr0, eax        ; enable caching
+
+        mov     eax, cr3
+        mov     cr3, eax        ;flush tlb
+
+        bt      [cpu_caps], CAPS_PGE
+        jnc     @F
+
+        mov     eax, cr4
+        bts     eax, 7          ;set cr4.PGE flag
+        mov     cr4, eax
+@@:
         ret
 endp
 
@@ -695,12 +739,15 @@ end virtual
         jmp     @b
 @@:
 
-; 9i. Configure MTRR_DEF_TYPE.
-        mov     ecx, 0x2FF
-        rdmsr
-        or      ah, 8   ; enable variable-ranges MTRR
-        and     al, 0xF0; default memtype = UC
+; 9i. Check PAT support and reprogram PAT_MASR for write combining memory
+        bt      [cpu_caps], CAPS_PAT
+        jnc     @F
+
+        mov     ecx, MSR_CR_PAT
+        mov     eax, PAT_VALUE  ;UC UCM WC WB
+        mov     edx, eax
         wrmsr
+@@:
 
 ; 9j. Changes are done.
         call    mtrr_end_change
@@ -738,7 +785,9 @@ proc set_mtrr stdcall, base:dword,size:dword,mem_type:dword
         ret
 .found:
 ; found, write values
+        push    ecx
         call    mtrr_begin_change
+        pop     ecx
         xor     edx, edx
         mov     eax, [base]
         or      eax, [mem_type]
diff --git a/kernel/trunk/data32.inc b/kernel/trunk/data32.inc
index c76de9acad..007092fc09 100644
--- a/kernel/trunk/data32.inc
+++ b/kernel/trunk/data32.inc
@@ -219,8 +219,6 @@ dll_cur_addr   dd MIN_DEFAULT_DLL_ADDR
 
 
 align 4
-pte_valid_mask dd 0xFFFFF000+PG_SHARED+PG_NOCACHE+PG_UWR
-
 keyboard   dd 1
 syslang    dd 1
 
@@ -363,6 +361,7 @@ next_memblock       rd 1
 
 mst                 MEM_STATE
 
+pte_valid_mask      rd 1
 page_start          rd 1
 page_end            rd 1
 sys_page_map        rd 1
diff --git a/kernel/trunk/kernel.asm b/kernel/trunk/kernel.asm
index ef88e5396c..f4919f0a5c 100644
--- a/kernel/trunk/kernel.asm
+++ b/kernel/trunk/kernel.asm
@@ -351,17 +351,26 @@ high_code:
         mov     fs, cx
         mov     gs, bx
 
+        xor     eax, eax
+        mov     ebx, 0xFFFFF000+PG_SHARED+PG_NOCACHE+PG_UWR
+        bt      [cpu_caps], CAPS_PAT
+        setc    al
+        shl     eax, 7
+        or      ebx, eax
+
         mov     eax, PG_GLOBAL
         bt      [cpu_caps], CAPS_PGE
         jnc     @F
 
         or      [sys_proc+PROC.pdt_0+(OS_BASE shr 20)], eax
-        or      [pte_valid_mask], eax
+        or      ebx, eax
 
-        mov     ebx, cr4
-        or      ebx, CR4_PGE
-        mov     cr4, ebx
+        mov     eax, cr4
+        or      eax, CR4_PGE
+        mov     cr4, eax
 @@:
+        mov     [pte_valid_mask], ebx
+
         xor     eax, eax
         mov     dword [sys_proc+PROC.pdt_0], eax
         mov     dword [sys_proc+PROC.pdt_0+4], eax