Files
system76-edk2/MdePkg/Library/BaseLib/X64/DisablePaging64.S
qhuang8 2561f56540 1. Fix the bug that we should use rip relative addressing for x64 label to prevent GNU assembly generate incorrect code.
2. Sync the bug fix of MS assembly in r8455.
3. Correct the function prototype in comments.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8456 6f19259b-4bc3-4df7-8a09-765794883524
2009-06-03 08:15:18 +00:00

68 lines
2.5 KiB
ArmAsm

#------------------------------------------------------------------------------
#
# 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 UINT32 EntryPoint,
# IN UINT32 Context1, OPTIONAL
# IN UINT32 Context2, OPTIONAL
# IN UINT32 NewStack
# );
#------------------------------------------------------------------------------
ASM_GLOBAL ASM_PFX(InternalX86DisablePaging64)
ASM_PFX(InternalX86DisablePaging64):
cli
lea L1(%rip), %r10
mov %r8d, %esi
mov %r9d, %edi
mov 0x28(%rsp), %eax # eax <- New Stack
push %rcx # push Cs to stack
push %r10
.byte 0x48, 0xcb # retq: Use far return to load CS register from stack
# (Use raw byte code since some GNU assemblers generates incorrect code for "retq")
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