;------------------------------------------------------------------------------ | |
; @file | |
; Transition from 32 bit flat protected mode into 64 bit flat protected mode | |
; | |
; Copyright (c) 2008 - 2018, Intel Corporation. All rights reserved.<BR> | |
; Copyright (c) 2019, Citrix Systems, Inc. | |
; | |
; SPDX-License-Identifier: BSD-2-Clause-Patent | |
; | |
;------------------------------------------------------------------------------ | |
BITS 32 | |
; | |
; Modified: EAX, EBX, ECX, EDX, ESP | |
; | |
Transition32FlatTo64Flat: | |
OneTimeCall SetCr3ForPageTables64 | |
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 | |
; | |
; backup ESP | |
; | |
mov ebx, esp | |
; | |
; recalculate delta | |
; | |
mov esp, PVH_SPACE(16) | |
call .delta | |
.delta: | |
pop edx | |
sub edx, ADDR_OF(.delta) | |
; | |
; push return addr and seg to the stack, then return far | |
; | |
push dword LINEAR_CODE64_SEL | |
mov eax, ADDR_OF(jumpTo64BitAndLandHere) | |
add eax, edx ; add delta | |
push eax | |
retf | |
BITS 64 | |
jumpTo64BitAndLandHere: | |
; | |
; restore ESP | |
; | |
mov esp, ebx | |
debugShowPostCode POSTCODE_64BIT_MODE | |
OneTimeCallRet Transition32FlatTo64Flat | |