mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-25 16:37:42 +01:00
61 lines
1.8 KiB
NASM
61 lines
1.8 KiB
NASM
;------------------------------------------------------------------------------
|
|
;
|
|
; Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
|
|
; SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
;
|
|
; Module Name:
|
|
;
|
|
; LongJump.Asm
|
|
;
|
|
; Abstract:
|
|
;
|
|
; Implementation of _LongJump() on IA-32.
|
|
;
|
|
;------------------------------------------------------------------------------
|
|
|
|
%include "Nasm.inc"
|
|
|
|
SECTION .text
|
|
|
|
extern ASM_PFX(PcdGet32 (PcdControlFlowEnforcementPropertyMask))
|
|
|
|
;------------------------------------------------------------------------------
|
|
; VOID
|
|
; EFIAPI
|
|
; InternalLongJump (
|
|
; IN BASE_LIBRARY_JUMP_BUFFER *JumpBuffer,
|
|
; IN UINTN Value
|
|
; );
|
|
;------------------------------------------------------------------------------
|
|
global ASM_PFX(InternalLongJump)
|
|
ASM_PFX(InternalLongJump):
|
|
|
|
mov eax, [ASM_PFX(PcdGet32 (PcdControlFlowEnforcementPropertyMask))]
|
|
test eax, eax
|
|
jz CetDone
|
|
mov eax, cr4
|
|
bt eax, 23 ; check if CET is enabled
|
|
jnc CetDone
|
|
|
|
mov edx, [esp + 4] ; edx = JumpBuffer
|
|
mov edx, [edx + 24] ; edx = target SSP
|
|
READSSP_EAX
|
|
sub edx, eax ; edx = delta
|
|
mov eax, edx ; eax = delta
|
|
|
|
shr eax, 2 ; eax = delta/sizeof(UINT32)
|
|
INCSSP_EAX
|
|
|
|
CetDone:
|
|
|
|
pop eax ; skip return address
|
|
pop edx ; edx <- JumpBuffer
|
|
pop eax ; eax <- Value
|
|
mov ebx, [edx]
|
|
mov esi, [edx + 4]
|
|
mov edi, [edx + 8]
|
|
mov ebp, [edx + 12]
|
|
mov esp, [edx + 16]
|
|
jmp dword [edx + 20] ; restore "eip"
|
|
|