mirror of https://github.com/acidanthera/audk.git
47 lines
1.4 KiB
NASM
47 lines
1.4 KiB
NASM
;------------------------------------------------------------------------------
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; @file
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; Transition from 32 bit flat protected mode into 64 bit flat protected mode
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;
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; Copyright (c) 2008 - 2009, Intel Corporation. All rights reserved.<BR>
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; 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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;------------------------------------------------------------------------------
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BITS 32
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;
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; Modified: EAX
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;
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Transition32FlatTo64Flat:
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mov eax, ((ADDR_OF_START_OF_RESET_CODE & ~0xfff) - 0x1000)
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mov cr3, eax
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mov eax, cr4
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bts eax, 5 ; enable PAE
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mov cr4, eax
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mov ecx, 0xc0000080
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rdmsr
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bts eax, 8 ; set LME
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wrmsr
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mov eax, cr0
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bts eax, 31 ; set PG
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mov cr0, eax ; enable paging
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jmp LINEAR_CODE64_SEL:ADDR_OF(jumpTo64BitAndLandHere)
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BITS 64
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jumpTo64BitAndLandHere:
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debugShowPostCode POSTCODE_64BIT_MODE
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OneTimeCallRet Transition32FlatTo64Flat
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