EmulatorPkg/Unix/Host/X64/SwitchStack.S

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   2 #
   3 # Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   4 # Portitions copyright (c) 2011, Apple Inc. All rights reserved.
   5 # This program and the accompanying materials
   6 # are licensed and made available under the terms and conditions of the BSD License
   7 # which accompanies this distribution.  The full text of the license may be found at
   8 # http://opensource.org/licenses/bsd-license.php.
   9 #
  10 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 #
  13 #------------------------------------------------------------------------------
  14
  15
  16 #------------------------------------------------------------------------------
  17 # Routine Description:
  18 #
  19 #   Routine for switching stacks with 2 parameters EFI ABI
  20 #   Convert UNIX to EFI ABI
  21 #
  22 # Arguments:
  23 #
  24 #   (rdi) EntryPoint    - Entry point with new stack.
  25 #   (rsi) Context1      - Parameter1 for entry point. (rcx)
  26 #   (rdx) Context2      - Parameter2 for entry point. (rdx)
  27 #   (rcx) NewStack      - The pointer to new stack.
  28 #
  29 # Returns:
  30 #
  31 #   None
  32 #
  33 #------------------------------------------------------------------------------
  34 ASM_GLOBAL ASM_PFX(PeiSwitchStacks)
  35 ASM_PFX(PeiSwitchStacks):
  36     pushq   $0            // tells gdb to stop unwinding frame
  37     movq    %rsp, %rbp
  38
  39     movq    %rcx, %rsp    // update stack pointer
  40
  41     movq    %rdi, %rax    // entry point to %rax
  42     movq    %rsi, %rcx    // Adjust Context1
  43                           // Context2 already in the rigth spot
  44
  45     #
  46     # Reserve space for register parameters (rcx, rdx, r8 & r9) on the stack,
  47     # in case the callee wishes to spill them.
  48     #
  49     subq    $32, %rsp  // 32-byte shadow space plus alignment pad
  50     call    *%rax
  51
  52
  53