audk/EmulatorPkg/Sec/X64/SwitchRam.asm

77 lines
2.8 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
; Portitions copyright (c) 2011, Apple Inc. 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.
;
;------------------------------------------------------------------------------
EXTERN CopyMem:PROC
EXTERN ZeroMem:PROC
.code
;------------------------------------------------------------------------------
; EFI_STATUS
; EFIAPI
; SecTemporaryRamSupport (
; IN CONST EFI_PEI_SERVICES **PeiServices, // %rcx
; IN EFI_PHYSICAL_ADDRESS TemporaryMemoryBase, // %rdx
; IN EFI_PHYSICAL_ADDRESS PermanentMemoryBase, // %r8
; IN UINTN CopySize // %r9
; )
;------------------------------------------------------------------------------
SecTemporaryRamSupport PROC
; Adjust callers %rbp to account for stack move
sub rbp, rdx ; Calc offset of %rbp in Temp Memory
add rbp, r8 ; add in permanent base to offset
push rbp ; stack frame is for the debugger
mov rbp, rsp
push rdx ; Save TemporaryMemoryBase
push r8 ; Save PermanentMemoryBase
push r9 ; Save CopySize
;
; Copy all of temp RAM to permanent memory, including stack
;
; CopyMem (PermanentMemoryBase, TemporaryMemoryBase, CopySize);
; %rcx, %rdx, %r8
mov rcx, r8 ; Shift arguments
mov r8, r9
sub rsp, 028h ; Allocate register spill area & 16-byte align stack
call CopyMem
; Temp mem stack now copied to permanent location. %esp still in temp memory
add rsp, 028h
pop r9 ; CopySize (old stack)
pop r8 ; PermanentMemoryBase (old stack)
pop rdx ; TemporaryMemoryBase (old stack)
mov rcx, rsp ; Move to new stack
sub rcx, rdx ; Calc offset of stack in Temp Memory
add rcx, r8 ; Calc PermanentMemoryBase address
mov rsp, rcx ; Update stack
; Stack now points to permanent memory
; ZeroMem (TemporaryMemoryBase /* rcx */, CopySize /* rdx */);
mov rcx, rdx
mov rdx, r9
sub rsp, 028h ; Allocate register spill area & 16-byte align stack
call ZeroMem
add rsp, 028h
; This data comes off the NEW stack
pop rbp
ret
SecTemporaryRamSupport ENDP
END