audk/ArmPlatformPkg/Library/ArmPlatformStackLib/AArch64/ArmPlatformStackLib.S

//
//  Copyright (c) 2012-2014, ARM Limited. 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.
//
//

#include <AsmMacroIoLibV8.h>

//VOID
//ArmPlatformStackSet (
//  IN UINTN StackBase,
//  IN UINTN MpId,
//  IN UINTN PrimaryStackSize,
//  IN UINTN SecondaryStackSize
//  );
ASM_FUNC(ArmPlatformStackSet)
  // Save parameters
  mov   x6, x3
  mov   x5, x2
  mov   x4, x1
  mov   x3, x0

  // Save the Link register
  mov   x7, x30

  // Identify Stack
  mov   x0, x1
  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
  cmp   x0, #1

  // Restore parameters
  mov   x0, x3
  mov   x1, x4
  mov   x2, x5
  mov   x3, x6

  // Restore the Link register
  mov   x30, x7

  b.ne  0f

  b     ASM_PFX(ArmPlatformStackSetPrimary)
0:b     ASM_PFX(ArmPlatformStackSetSecondary)

//VOID
//ArmPlatformStackSetPrimary (
//  IN UINTN StackBase,
//  IN UINTN MpId,
//  IN UINTN PrimaryStackSize,
//  IN UINTN SecondaryStackSize
//  );
ASM_FUNC(ArmPlatformStackSetPrimary)
  // Save the Link register
  mov   x4, x30

  // Add stack of primary stack to StackBase
  add   x0, x0, x2

  // Compute SecondaryCoresCount * SecondaryCoreStackSize
  MOV32 (w1, FixedPcdGet32(PcdCoreCount) - 1)
  mul   x3, x3, x1

  // Set Primary Stack ((StackBase + PrimaryStackSize) + (SecondaryCoresCount * SecondaryCoreStackSize))
  add   sp, x0, x3

  br    x4

//VOID
//ArmPlatformStackSetSecondary (
//  IN UINTN StackBase,
//  IN UINTN MpId,
//  IN UINTN PrimaryStackSize,
//  IN UINTN SecondaryStackSize
//  );
ASM_FUNC(ArmPlatformStackSetSecondary)
  // Save the Link register
  mov   x4, x30
  mov   sp, x0

  // Get Core Position
  mov   x0, x1
  bl    ASM_PFX(ArmPlatformGetCorePosition)
  mov   x5, x0

  // Get Primary Core Position
  bl    ASM_PFX(ArmPlatformGetPrimaryCoreMpId)
  bl    ASM_PFX(ArmPlatformGetCorePosition)

  // Get Secondary Core Position. We should get consecutive secondary stack number from 1...(CoreCount-1)
  cmp   x5, x0
  b.ls  1f
  // Decrement the position if after the primary core
  sub   x5, x5, #1
1:
  add   x5, x5, #1

  // Compute top of the secondary stack
  mul   x3, x3, x5

  // Set stack
  add   sp, sp, x3

  br    x4