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#------------------------------------------------------------------------------
#
# Copyright (c) 2006 - 2008, Intel Corporation
# 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.
#
# Module Name:
#
# DisablePaging64.S
#
# Abstract:
#
# AsmDisablePaging64 function
#
# Notes:
#
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# VOID
# EFIAPI
# InternalX86DisablePaging64 (
# IN UINT16 Cs,
# IN UINT64 EntryPoint,
# IN UINT64 Context1, OPTIONAL
# IN UINT32 Context2, OPTIONAL
# IN UINT64 NewStack
# );
#------------------------------------------------------------------------------
.global ASM_PFX(InternalX86DisablePaging64)
ASM_PFX(InternalX86DisablePaging64):
cli
shl $0x20,%rcx # rcx[32..47] <- Cs
lea L1, %eax
mov %r8d, %esi
or %rax, %rcx # rcx[0..47] <- Cs:@F
mov %r9d, %edi
mov 0x28(%rsp), %eax # eax <- New Stack
push %rcx
ret # switch to compatibility mode
L1:
mov %eax,%esp # set up new stack
mov %cr0,%rax
btr $0x1f,%eax
mov %rax,%cr0 # disable paging
mov %rdx,%rbx # save EntryPoint to rbx, for rdmsr will overwrite rdx
mov $0xc0000080,%ecx
rdmsr
and $0xfe,%ah # clear LME
wrmsr
mov %cr4,%rax
and $0xdf,%al # clear PAE
mov %rax,%cr4
push %rdi # push Context2
push %rsi # push Context1
callq *%rbx # transfer control to EntryPoint
jmp . # no one should get here
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