audk/EmulatorPkg/Sec/Ia32/SwitchRam.S

90 lines
2.3 KiB
ArmAsm

#------------------------------------------------------------------------------
#
# Copyright (c) 2007, Intel Corporation. All rights reserved.<BR>
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
# Module Name:
#
# Stack.asm
#
# Abstract:
#
# Switch the stack from temporary memory to permanent memory.
#
#------------------------------------------------------------------------------
.text
//------------------------------------------------------------------------------
// VOID
// EFIAPI
// SecSwitchStack (
// UINT32 TemporaryMemoryBase,
// UINT32 PermenentMemoryBase
// )//
//------------------------------------------------------------------------------
ASM_GLOBAL ASM_PFX(SecSwitchStack)
ASM_PFX(SecSwitchStack):
#
# Save three register: eax, ebx, ecx
#
push %eax
push %ebx
push %ecx
push %edx
#
# !!CAUTION!! this function address's is pushed into stack after
# migration of whole temporary memory, so need save it to permanent
# 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 permanent memory at first.
# Then, Fixup the esp point to permanent memory
#
movl %esp, %eax
subl %ebx, %eax
addl %ecx, %eax
movl (%esp), %edx # copy pushed register's value to permanent memory
movl %edx, (%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
movl %edx, 16(%eax)
movl %eax, %esp # From now, esp is pointed to permanent memory
#
# Fixup the ebp point to permanent memory
#
#ifndef __APPLE__
movl %ebp, %eax
subl %ebx, %eax
addl %ecx, %eax
movl %eax, %ebp # From now, ebp is pointed to permanent memory
#
# Fixup callee's ebp point for PeiDispatch
#
movl (%ebp), %eax
subl %ebx, %eax
addl %ecx, %eax
movl %eax, (%ebp) # From now, Temporary's PPI caller's stack is in permanent memory
#endif
pop %edx
pop %ecx
pop %ebx
pop %eax
ret