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## @file
# Switch the stack from temporary memory to permenent memory.
#
# Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
#
# 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
#
##
#------------------------------------------------------------------------------
# VOID
# EFIAPI
# SecSwitchStack (
# UINT32 TemporaryMemoryBase,
# UINT32 PermenentMemoryBase
# )#
#------------------------------------------------------------------------------
ASM_GLOBAL ASM_PFX (SecSwitchStack)
ASM_PFX(SecSwitchStack):
#
# Save standard registers so they can be used to change stack
#
pushl %eax
pushl %ebx
pushl %ecx
pushl %edx
#
# !!CAUTION!! this function address's is pushed into stack after
# migration of whole temporary memory, so need save it to permenent
# memory at first!
#
movl 20(%esp), %ebx # Save the first parameter
movl 24(%esp), %ecx # Save the second parameter
#
# Save this function's return address into permenent memory at first.
# Then, Fixup the esp point to permenent memory
#
movl %esp, %eax
subl %ebx, %eax
addl %ecx, %eax
movl 0(%esp), %edx # copy pushed register's value to permenent memory
movl %edx, 0(%eax)
movl 4(%esp), %edx
movl %edx, 4(%eax)
movl 8(%esp), %edx
movl %edx, 8(%eax)
movl 12(%esp), %edx
movl %edx, 12(%eax)
movl 16(%esp), %edx # Update this function's return address into permenent memory
movl %edx, 16(%eax)
movl %eax, %esp # From now, esp is pointed to permenent memory
#
# Fixup the ebp point to permenent memory
#
movl %ebp, %eax
subl %ebx, %eax
addl %ecx, %eax
movl %eax, %ebp # From now, ebp is pointed to permenent memory
popl %edx
popl %ecx
popl %ebx
popl %eax
ret
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