audk/OvmfPkg/ResetVector/Ia32/32FlatTo64Flat.asm

52 lines
1.5 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2008, Intel Corporation
; All rights reserved. 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.
;
; Module Name:
;
; 32FlatTo64Flat.asm
;
; Abstract:
;
; Transition from 32 bit flat protected mode into 64 bit flat protected mode
;
;------------------------------------------------------------------------------
BITS 32
Transition32FlatTo64Flat:
mov eax, ((ADDR_OF_START_OF_RESET_CODE & ~0xfff) - 0x1000)
mov cr3, eax
mov eax, cr4
bts eax, 5 ; enable PAE
mov cr4, eax
mov ecx, 0xc0000080
rdmsr
bts eax, 8 ; set LME
wrmsr
mov eax, cr0
bts eax, 31 ; set PG
mov cr0, eax ; enable paging
jmp LINEAR_CODE64_SEL:ADDR_OF(jumpTo64BitAndLandHere)
BITS 64
jumpTo64BitAndLandHere:
writeToSerialPort '6'
writeToSerialPort '4'
writeToSerialPort ' '
OneTimeCallRet Transition32FlatTo64Flat