UefiCpuPkg: Move AsmRelocateApLoopStart from Mpfuncs.nasm to AmdSev.nasm

[mirror_edk2.git] / MdePkg / Library / BaseLib / AArch64 / SwitchStack.asm

;------------------------------------------------------------------------------\r
;\r
; Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>\r
; Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>\r
; Portions copyright (c) 2011 - 2013, ARM Limited. All rights reserved.<BR>\r
; SPDX-License-Identifier: BSD-2-Clause-Patent\r
;\r
;------------------------------------------------------------------------------\r
\r
  EXPORT InternalSwitchStackAsm\r
  EXPORT CpuPause\r
  AREA BaseLib_LowLevel, CODE, READONLY\r
\r
;/**\r
;\r
;  This allows the caller to switch the stack and goes to the new entry point\r
;\r
; @param      EntryPoint   The pointer to the location to enter\r
; @param      Context      Parameter to pass in\r
; @param      Context2     Parameter2 to pass in\r
; @param      NewStack     New Location of the stack\r
;\r
; @return     Nothing. Goes to the Entry Point passing in the new parameters\r
;\r
;**/\r
;VOID\r
;EFIAPI\r
;InternalSwitchStackAsm (\r
;  SWITCH_STACK_ENTRY_POINT EntryPoint,\r
;  VOID  *Context,\r
;  VOID  *Context2,\r
;  VOID  *NewStack\r
;  );\r
;\r
InternalSwitchStackAsm\r
    mov   x29, #0\r
    mov   x30, x0\r
    mov   sp, x3\r
    mov   x0, x1\r
    mov   x1, x2\r
    ret\r
\r
;/**\r
;\r
;  Requests CPU to pause for a short period of time.\r
;\r
;  Requests CPU to pause for a short period of time. Typically used in MP\r
;  systems to prevent memory starvation while waiting for a spin lock.\r
;\r
;**/\r
;VOID\r
;EFIAPI\r
;CpuPause (\r
;  VOID\r
;  )\r
;\r
CpuPause\r
    nop\r
    nop\r
    nop\r
    nop\r
    nop\r
    ret\r
\r
  END\r