mirror of https://github.com/acidanthera/audk.git
68 lines
2.4 KiB
NASM
68 lines
2.4 KiB
NASM
;------------------------------------------------------------------------------
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;
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; Copyright (c) 2006 - 2008, Intel Corporation
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; All rights reserved. This program and the accompanying materials
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; are licensed and made available under the terms and conditions of the BSD License
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; which accompanies this distribution. The full text of the license may be found at
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; http://opensource.org/licenses/bsd-license.php
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;
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; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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;
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; Module Name:
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;
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; DisablePaging64.Asm
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;
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; Abstract:
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;
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; AsmDisablePaging64 function
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;
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; Notes:
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;
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;------------------------------------------------------------------------------
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.code
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;------------------------------------------------------------------------------
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; VOID
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; EFIAPI
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; InternalX86DisablePaging64 (
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; IN UINT16 Cs,
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; IN UINT32 EntryPoint,
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; IN UINT32 Context1, OPTIONAL
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; IN UINT32 Context2, OPTIONAL
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; IN UINT32 NewStack
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; );
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;------------------------------------------------------------------------------
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InternalX86DisablePaging64 PROC
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cli
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shl rcx, 32 ; rcx[32..47] <- Cs
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lea eax, @F
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mov esi, r8d
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or rcx, rax ; rcx[0..47] <- Cs:@F
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mov edi, r9d
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mov eax, [rsp + 28h] ; eax <- New Stack
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push rcx
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retf ; switch to compatibility mode
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@@:
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mov esp, eax ; set up new stack
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mov rax, cr0
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btr eax, 31
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mov cr0, rax ; disable paging
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mov rbx, rdx ; save EntryPoint to rbx, for rdmsr will overwrite rdx
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mov ecx, 0c0000080h
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rdmsr
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and ah, NOT 1 ; clear LME
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wrmsr
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mov rax, cr4
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and al, NOT (1 SHL 5) ; clear PAE
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mov cr4, rax
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push rdi ; push Context2
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push rsi ; push Context1
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call rbx ; transfer control to EntryPoint
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hlt ; no one should get here
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InternalX86DisablePaging64 ENDP
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END
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