mirror of https://github.com/acidanthera/audk.git
45 lines
1.0 KiB
C
45 lines
1.0 KiB
C
/** @file
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AsmWriteCr4 function
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Copyright (c) 2006 - 2007, Intel Corporation<BR>
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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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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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// Include common header file for this module.
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//
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/**
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Writes a value to Control Register 4 (CR4).
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Writes and returns a new value to CR4. This function is only available on
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IA-32 and X64. This writes a 32-bit value on IA-32 and a 64-bit value on X64.
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@param Cr4 The value to write to CR4.
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@return The value written to CR4.
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**/
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UINTN
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EFIAPI
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AsmWriteCr4 (
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UINTN Value
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)
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{
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_asm {
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mov eax, Value
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_emit 0x0f // mov cr4, eax
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_emit 0x22
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_emit 0xE0
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}
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}
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