diff --git a/kernel/trunk/core/apic.inc b/kernel/trunk/core/apic.inc
index 47ffc128e..60aa3de09 100644
--- a/kernel/trunk/core/apic.inc
+++ b/kernel/trunk/core/apic.inc
@@ -61,7 +61,7 @@ APIC_init:
         call    IRQ_mask_all
 
 ; IOAPIC init
-        stdcall map_io_mem, [acpi_ioapic_base], 0x20, PG_SW
+        stdcall map_io_mem, [acpi_ioapic_base], 0x20, PG_SW+PG_NOCACHE
         mov     [IOAPIC_base], eax
 
         mov     eax, IOAPIC_VER
@@ -121,14 +121,11 @@ APIC_init:
 ;===========================================================
 align 4
 LAPIC_init:
-        ; Check MSR support
-        ;....
-        ; Get LAPIC base address
-; mov ecx, 0x1b
-; rdmsr       ; it may be replaced to
-; and ax, 0xf000    ; mov eax, 0xfee00000
 
-        stdcall map_io_mem, [acpi_lapic_base], 0x1000, PG_SW
+        cmp     [LAPIC_BASE], 0
+        jne     .done
+
+        stdcall map_io_mem, [acpi_lapic_base], 0x1000, PG_SW+PG_NOCACHE
         mov     [LAPIC_BASE], eax
         mov     esi, eax
 
@@ -200,6 +197,8 @@ LAPIC_init:
         ; Start (every 0.01 sec)
         mov     dword[esi + APIC_LVT_timer], 0x30020; periodic int 0x20
         mov     dword[esi + APIC_timer_init], eax
+
+.done:
         ret
 
 ;===========================================================
diff --git a/kernel/trunk/gui/window.inc b/kernel/trunk/gui/window.inc
index 91d062886..c641c7955 100644
--- a/kernel/trunk/gui/window.inc
+++ b/kernel/trunk/gui/window.inc
@@ -548,6 +548,7 @@ align 4
 align 4
 .exit:
         pop     ebp
+        inc     [_display.mask_seqno]
         popfd
         pop     esi
         ret
@@ -998,6 +999,7 @@ waredraw: ;////////////////////////////////////////////////////////////////////
         mov     edi, [TASK_COUNT]
         movzx   esi, word[WIN_POS + edi * 2]
         call    window._.set_screen
+        inc     [_display.mask_seqno]
         popad
 
         ; tell application to redraw itself
@@ -1102,7 +1104,7 @@ align 4
         add     ecx, eax
         add     edx, ebx
         call    ebp
-
+        inc     [_display.mask_seqno]
         mov     byte[MOUSE_BACKGROUND], 0
 ;--------------------------------------
 align 4
@@ -1204,6 +1206,7 @@ align 4
 ;--------------------------------------
 align 4
 .exit:
+        inc     [_display.mask_seqno]
         ret
 ;------------------------------------------------------------------------------
 align 4
@@ -1949,6 +1952,7 @@ align 4
 align 4
 .exit:
         popad
+        inc     [_display.mask_seqno]
         ret
 ;--------------------------------------
 align 4
diff --git a/kernel/trunk/init.inc b/kernel/trunk/init.inc
index 8f9627778..f70e2eed6 100644
--- a/kernel/trunk/init.inc
+++ b/kernel/trunk/init.inc
@@ -432,6 +432,11 @@ proc test_cpu
         ret
 endp
 
+iglobal
+align 4
+acpi_lapic_base   dd 0xfee00000   ; default local apic base
+endg
+
 uglobal
 align 4
 acpi_rsdp         rd 1
@@ -443,8 +448,10 @@ acpi_dev_size     rd 1
 
 acpi_rsdt_base    rd 1
 acpi_madt_base    rd 1
-acpi_lapic_base   rd 1
 acpi_ioapic_base  rd 1
+
+cpu_count         rd 1
+smpt              rd 16
 endg
 
 ACPI_HI_RSDP_WINDOW_START  equ 0x000E0000
@@ -493,6 +500,7 @@ rsdt_find:           ;ecx= rsdt edx= SIG
         lea     ebx, [ecx+36]
         mov     esi, [ecx+4]
         add     esi, ecx
+align 4
 .next:
         mov     eax, [ebx]
         cmp     [eax], edx
@@ -513,9 +521,7 @@ rsdt_find:           ;ecx= rsdt edx= SIG
         pop     ebx
         ret
 
-
 align 4
-
 check_acpi:
 
         call    acpi_locate
@@ -533,22 +539,47 @@ check_acpi:
         mov     ecx, [eax+36]
         mov     [acpi_lapic_base-OS_BASE], ecx
 
+        mov     edi, smpt-OS_BASE
+        mov     ebx, [ecx+0x20]
+        shr     ebx, 24              ; read APIC ID
+
+        mov     [edi], ebx           ; bootstrap always first
+        inc     [cpu_count-OS_BASE]
+        add     edi, 4
+
         lea     edx, [eax+44]
         mov     ecx, [eax+4]
         add     ecx, eax
 .check:
         mov     eax, [edx]
-        cmp     al, 1
-        je      .ioapic
+        cmp     al, 0
+        jne     .io_apic
 
+        shr     eax, 24              ; get APIC ID
+        cmp     eax, ebx             ; skip self
+        je      .next
+
+        test    [edx+4], byte 1      ; is enabled ?
+        jz      .next
+
+        cmp     [cpu_count-OS_BASE], 16
+        jae     .next
+
+        stosd                        ; store APIC ID
+        inc     [cpu_count-OS_BASE]
 .next:
+        mov     eax, [edx]
         movzx   eax, ah
         add     edx, eax
         cmp     edx, ecx
         jb      .check
 .done:
         ret
-.ioapic:
+
+.io_apic:
+        cmp     al, 1
+        jne     .next
+
         mov     eax, [edx+4]
         mov     [acpi_ioapic_base-OS_BASE], eax
-        ret
+        jmp     .next
diff --git a/kernel/trunk/kernel.asm b/kernel/trunk/kernel.asm
index 412b3ebcf..ffd415600 100644
--- a/kernel/trunk/kernel.asm
+++ b/kernel/trunk/kernel.asm
@@ -295,6 +295,8 @@ include 'init.inc'
 
 org OS_BASE+$
 
+include 'fdo.inc'
+
 align 4
 high_code:
         mov     ax, os_stack
@@ -980,6 +982,13 @@ if defined debug_com_base
 
 end if
 
+        mov     eax, [cpu_count]
+        test    eax, eax
+        jnz     @F
+        mov     al, 1                             ; at least one CPU
+@@:
+        DEBUGF  1, "K : %d CPU detected\n", eax
+
 ; START MULTITASKING
 
 ; A 'All set - press ESC to start' messages if need
@@ -1005,7 +1014,6 @@ end if
         ; Fly :)
 
 include 'unpacker.inc'
-include 'fdo.inc'
 
 align 4
 boot_log: