audk/EmulatorPkg/Sec/X64/SwitchRam.S

67 lines
2.3 KiB
ArmAsm

#------------------------------------------------------------------------------
#
# Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
# Portions copyright (c) 2011, Apple Inc. All rights reserved.
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
#------------------------------------------------------------------------------
// EFI_STATUS
// EFIAPI
// SecTemporaryRamSupport (
// IN CONST EFI_PEI_SERVICES **PeiServices, // %rcx
// IN EFI_PHYSICAL_ADDRESS TemporaryMemoryBase, // %rdx
// IN EFI_PHYSICAL_ADDRESS PermanentMemoryBase, // %r8
// IN UINTN CopySize // %r9
// )
//
ASM_GLOBAL ASM_PFX(SecTemporaryRamSupport)
ASM_PFX(SecTemporaryRamSupport):
// Adjust callers %rbp to account for stack move
subq %rdx, %rbp // Calc offset of %rbp in Temp Memory
addq %r8, %rbp // add in permanent base to offset
pushq %rbp // stack frame is for the debugger
movq %rsp, %rbp
pushq %rdx // Save TemporaryMemoryBase
pushq %r8 // Save PermanentMemoryBase
pushq %r9 // Save CopySize
//
// Copy all of temp RAM to permanent memory, including stack
//
// CopyMem (PermanentMemoryBase, TemporaryMemoryBase, CopySize);
// %rcx, %rdx, %r8
movq %r8, %rcx // Shift arguments
movq %r9, %r8
subq $0x28, %rsp // Allocate register spill area & 16-byte align stack
call ASM_PFX(CopyMem)
// Temp mem stack now copied to permanent location. %esp still in temp memory
addq $0x28, %rsp
popq %r9 // CopySize (old stack)
popq %r8 // PermanentMemoryBase (old stack)
popq %rdx // TemporaryMemoryBase (old stack)
movq %rsp, %rcx // Move to new stack
subq %rdx, %rcx // Calc offset of stack in Temp Memory
addq %r8, %rcx // Calc PermanentMemoryBase address
movq %rcx, %rsp // Update stack
// Stack now points to permanent memory
// ZeroMem (TemporaryMemoryBase /* rcx */, CopySize /* rdx */);
movq %rdx, %rcx
movq %r9, %rdx
subq $0x28, %rsp // Allocate register spill area & 16-byte align stack
call ASM_PFX(ZeroMem)
addq $0x28, %rsp
// This data comes off the NEW stack
popq %rbp
ret