1#------------------------------------------------------------------------------
2#
3# Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
4# This program and the accompanying materials
5# are licensed and made available under the terms and conditions of the BSD License
6# which accompanies this distribution.  The full text of the license may be found at
7# http://opensource.org/licenses/bsd-license.php.
8#
9# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11#
12# Module Name:
13#
14#   EnablePaging64.S
15#
16# Abstract:
17#
18#   InternalX86EnablePaging64 function
19#
20# Notes:
21#
22#------------------------------------------------------------------------------
23
24ASM_GLOBAL ASM_PFX(InternalX86EnablePaging64)
25
26#------------------------------------------------------------------------------
27# VOID
28# EFIAPI
29# InternalX86EnablePaging64 (
30#   IN      UINT16                    CodeSelector,
31#   IN      UINT64                    EntryPoint,
32#   IN      UINT64                    Context1,    OPTIONAL
33#   IN      UINT64                    Context2,    OPTIONAL
34#   IN      UINT64                    NewStack
35#   );
36#------------------------------------------------------------------------------
37ASM_PFX(InternalX86EnablePaging64):
38    cli
39    movl    $LongStart, (%esp)          # offset for far retf, seg is the 1st arg
40    movl    %cr4, %eax
41    orb     $0x20, %al
42    movl    %eax, %cr4                  # enable PAE
43    movl    $0xc0000080, %ecx
44    rdmsr
45    orb     $1, %ah                     # set LME
46    wrmsr
47    movl    %cr0, %eax
48    btsl    $31, %eax                   # set PG
49    movl    %eax, %cr0                  # enable paging
50    lret                                # topmost 2 dwords hold the address
51LongStart:                              # long mode starts here
52    .byte   0x67, 0x48                  # 32-bit address size, 64-bit operand size
53    movl    (%esp), %ebx                # mov rbx, [esp]
54    .byte   0x67, 0x48
55    movl    8(%esp), %ecx               # mov rcx, [esp + 8]
56    .byte   0x67, 0x48
57    movl    0x10(%esp), %edx            # mov rdx, [esp + 10h]
58    .byte   0x67, 0x48
59    movl    0x18(%esp), %esp            # mov rsp, [esp + 18h]
60    .byte   0x48
61    addl    $-0x20, %esp                # add rsp, -20h
62    call    *%ebx                       # call rbx
63    jmp     .                           # no one should get here
64