;------------------------------------------------------------------------------ | |
; @file | |
; Sets the CR3 register for 64-bit paging | |
; | |
; Copyright (c) 2008 - 2013, Intel Corporation. All rights reserved.<BR> | |
; This program and the accompanying materials | |
; are licensed and made available under the terms and conditions of the BSD License | |
; which accompanies this distribution. The full text of the license may be found at | |
; http://opensource.org/licenses/bsd-license.php | |
; | |
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
; | |
;------------------------------------------------------------------------------ | |
BITS 32 | |
%define PAGE_PRESENT 0x01 | |
%define PAGE_READ_WRITE 0x02 | |
%define PAGE_USER_SUPERVISOR 0x04 | |
%define PAGE_WRITE_THROUGH 0x08 | |
%define PAGE_CACHE_DISABLE 0x010 | |
%define PAGE_ACCESSED 0x020 | |
%define PAGE_DIRTY 0x040 | |
%define PAGE_PAT 0x080 | |
%define PAGE_GLOBAL 0x0100 | |
%define PAGE_2M_MBO 0x080 | |
%define PAGE_2M_PAT 0x01000 | |
%define PAGE_2M_PDE_ATTR (PAGE_2M_MBO + \ | |
PAGE_ACCESSED + \ | |
PAGE_DIRTY + \ | |
PAGE_READ_WRITE + \ | |
PAGE_PRESENT) | |
%define PAGE_PDP_ATTR (PAGE_ACCESSED + \ | |
PAGE_READ_WRITE + \ | |
PAGE_PRESENT) | |
; | |
; Modified: EAX, ECX | |
; | |
SetCr3ForPageTables64: | |
; | |
; For OVMF, build some initial page tables at | |
; PcdOvmfSecPageTablesBase - (PcdOvmfSecPageTablesBase + 0x6000). | |
; | |
; This range should match with PcdOvmfSecPageTablesSize which is | |
; declared in the FDF files. | |
; | |
; At the end of PEI, the pages tables will be rebuilt into a | |
; more permanent location by DxeIpl. | |
; | |
mov ecx, 6 * 0x1000 / 4 | |
xor eax, eax | |
clearPageTablesMemoryLoop: | |
mov dword[ecx * 4 + PT_ADDR (0) - 4], eax | |
loop clearPageTablesMemoryLoop | |
; | |
; Top level Page Directory Pointers (1 * 512GB entry) | |
; | |
mov dword[PT_ADDR (0)], PT_ADDR (0x1000) + PAGE_PDP_ATTR | |
; | |
; Next level Page Directory Pointers (4 * 1GB entries => 4GB) | |
; | |
mov dword[PT_ADDR (0x1000)], PT_ADDR (0x2000) + PAGE_PDP_ATTR | |
mov dword[PT_ADDR (0x1008)], PT_ADDR (0x3000) + PAGE_PDP_ATTR | |
mov dword[PT_ADDR (0x1010)], PT_ADDR (0x4000) + PAGE_PDP_ATTR | |
mov dword[PT_ADDR (0x1018)], PT_ADDR (0x5000) + PAGE_PDP_ATTR | |
; | |
; Page Table Entries (2048 * 2MB entries => 4GB) | |
; | |
mov ecx, 0x800 | |
pageTableEntriesLoop: | |
mov eax, ecx | |
dec eax | |
shl eax, 21 | |
add eax, PAGE_2M_PDE_ATTR | |
mov [ecx * 8 + PT_ADDR (0x2000 - 8)], eax | |
loop pageTableEntriesLoop | |
; | |
; Set CR3 now that the paging structures are available | |
; | |
mov eax, PT_ADDR (0) | |
mov cr3, eax | |
OneTimeCallRet SetCr3ForPageTables64 |