Rename dirs
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@16 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
189
MdePkg/Library/BaseLib/X64/Thunk16.asm
Normal file
189
MdePkg/Library/BaseLib/X64/Thunk16.asm
Normal file
@@ -0,0 +1,189 @@
|
||||
;------------------------------------------------------------------------------
|
||||
;
|
||||
; Copyright (c) 2006, 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:
|
||||
;
|
||||
; Thunk.asm
|
||||
;
|
||||
; Abstract:
|
||||
;
|
||||
; Real mode thunk
|
||||
;
|
||||
;------------------------------------------------------------------------------
|
||||
|
||||
.data
|
||||
|
||||
NullSegSel DQ 0
|
||||
_16CsSegSel LABEL QWORD
|
||||
DW -1
|
||||
DW 0
|
||||
DB 0
|
||||
DB 9bh
|
||||
DB 8fh ; 16-bit segment
|
||||
DB 0
|
||||
_16BitDsSel LABEL QWORD
|
||||
DW -1
|
||||
DW 0
|
||||
DB 0
|
||||
DB 93h
|
||||
DB 8fh ; 16-bit segment
|
||||
DB 0
|
||||
GdtEnd LABEL QWORD
|
||||
|
||||
.const
|
||||
|
||||
_16Gdtr LABEL FWORD
|
||||
DW offset GdtEnd - offset NullSegSel - 1
|
||||
DQ offset NullSegSel
|
||||
|
||||
_16Idtr FWORD (1 SHL 10) - 1
|
||||
|
||||
.code
|
||||
|
||||
IA32_REGS STRUC 4t
|
||||
_EDI DD ?
|
||||
_ESI DD ?
|
||||
_EBP DD ?
|
||||
_ESP DD ?
|
||||
_EBX DD ?
|
||||
_EDX DD ?
|
||||
_ECX DD ?
|
||||
_EAX DD ?
|
||||
_DS DW ?
|
||||
_ES DW ?
|
||||
_FS DW ?
|
||||
_GS DW ?
|
||||
_RFLAGS DQ ?
|
||||
_EIP DD ?
|
||||
_CS DW ?
|
||||
_SS DW ?
|
||||
IA32_REGS ENDS
|
||||
|
||||
InternalAsmThunk16 PROC USES rbp rbx rsi rdi r12 r13 r14 r15
|
||||
mov eax, ds
|
||||
push rax
|
||||
mov eax, es
|
||||
push rax
|
||||
push fs
|
||||
push gs
|
||||
mov rsi, rcx ; rsi <- RegSet
|
||||
push sizeof (IA32_REGS)
|
||||
pop rcx
|
||||
movzx r8, (IA32_REGS ptr [rsi])._SS
|
||||
xor rdi, rdi
|
||||
mov edi, (IA32_REGS ptr [rsi])._ESP
|
||||
sub rdi, rcx ; reserve space on realmode stack
|
||||
push rdi ; save stack offset
|
||||
imul rax, r8, 16
|
||||
add rdi, rax ; rdi <- linear address of 16-bit stack
|
||||
rep movsb ; copy RegSet
|
||||
mov rsi, r8 ; si <- 16-bit stack segment
|
||||
pop rbx ; rbx <- 16-bit stack offset
|
||||
mov rdi, rdx ; rdi <- realmode patch
|
||||
lea eax, @BackToThunk ; rax <- address to back from real mode
|
||||
push rax ; use in a far return
|
||||
mov eax, cs
|
||||
mov [rsp + 4], eax ; save CS
|
||||
lea eax, @16Return ; thus @Return must < 4GB
|
||||
stosd ; set ret address offset
|
||||
xor eax, eax
|
||||
stosw ; set ret CS base to 0
|
||||
mov eax, esp
|
||||
stosd ; rsp must < 4GB
|
||||
mov eax, ss
|
||||
stosd
|
||||
mov rax, cr0
|
||||
mov ecx, eax ; ecx <- CR0
|
||||
and ecx, 7ffffffeh ; clear PE, PG bits
|
||||
stosd
|
||||
mov rax, cr4
|
||||
mov ebp, eax
|
||||
and ebp, 300h ; clear all but PCE and OSFXSR bits
|
||||
stosd
|
||||
sidt fword ptr [rsp + 70h] ; use parameter space to save IDTR
|
||||
sgdt fword ptr [rdi]
|
||||
lea edi, _16Idtr
|
||||
lea eax, @16Start ; rax <- seg:offset of @16Start
|
||||
push rax
|
||||
mov dword ptr [rsp + 4], 8
|
||||
push 10h
|
||||
pop rax ; rax <- 10h as dataseg selector
|
||||
lgdt _16Gdtr
|
||||
retf
|
||||
@16Start: ; 16-bit starts here
|
||||
mov ss, eax ; set SS to be a 16-bit segment
|
||||
mov cr0, rcx ; disable protected mode
|
||||
mov cr4, rbp
|
||||
DB 66h
|
||||
mov ecx, 0c0000080h
|
||||
rdmsr
|
||||
and ah, NOT 1 ; clear LME
|
||||
wrmsr
|
||||
mov ss, esi ; set up 16-bit stack
|
||||
mov sp, bx ; mov esp, ebx actually
|
||||
lidt fword ptr [edi]
|
||||
DB 66h, 61h ; popad
|
||||
DB 1fh ; pop ds
|
||||
DB 7 ; pop es
|
||||
pop fs
|
||||
pop gs
|
||||
add sp, 8 ; skip _RFLAGS
|
||||
DB 66h
|
||||
retf ; transfer control to 16-bit code
|
||||
@16Return:
|
||||
DB 66h
|
||||
push 0 ; high order 32 bits of rflags
|
||||
pushf ; pushfd actually
|
||||
push gs
|
||||
push fs
|
||||
DB 6 ; push es
|
||||
DB 1eh ; push ds
|
||||
DB 66h, 60h ; pushad
|
||||
DB 67h, 66h, 0c5h, 74h, 24h, 30h ; lds esi, [esp + 12*4]
|
||||
DB 66h
|
||||
mov eax, [esi + 12]
|
||||
mov cr4, rax ; restore CR4
|
||||
DB 66h
|
||||
lgdt fword ptr [esi + 16]
|
||||
DB 66h
|
||||
mov ecx, 0c0000080h
|
||||
rdmsr
|
||||
or ah, 1 ; set LME
|
||||
wrmsr
|
||||
DB 66h
|
||||
mov eax, [esi + 8]
|
||||
mov cr0, rax ; restore CR0
|
||||
xor ax, ax ; xor eax, eax actually
|
||||
mov eax, ss
|
||||
mov dword ptr (IA32_REGS ptr [esp])._SS, eax
|
||||
shl ax, 4 ; shl eax, 4 actually
|
||||
add ax, sp ; add eax, esp actually
|
||||
add sp, sizeof (IA32_REGS) ; add esp, sizeof (IA32_REGS)
|
||||
DB 66h
|
||||
mov dword ptr (IA32_REGS ptr [esp - sizeof (IA32_REGS)])._ESP, esp
|
||||
DB 66h
|
||||
lss esp, fword ptr [esi] ; restore protected mode stack
|
||||
DB 66h
|
||||
retf ; go back to protected mode
|
||||
@BackToThunk:
|
||||
lidt fword ptr [rsp + 68h] ; restore protected mode IDTR
|
||||
shl rax, 32
|
||||
shr rax, 32 ; clear high order 32 bits of RAX
|
||||
pop gs
|
||||
pop fs
|
||||
pop rcx
|
||||
mov es, ecx
|
||||
pop rcx
|
||||
mov ds, ecx
|
||||
ret
|
||||
InternalAsmThunk16 ENDP
|
||||
|
||||
END
|
Reference in New Issue
Block a user