mirror of https://github.com/acidanthera/audk.git
96 lines
2.2 KiB
C
96 lines
2.2 KiB
C
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/** @file
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RDRAND Support Routines for GCC environment.
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Copyright (c) 2013, 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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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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Generates a 16-bit random number through RDRAND instruction.
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@param[out] Rand Buffer pointer to store the random result.
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@retval TRUE RDRAND call was successful.
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@retval FALSE Failed attempts to call RDRAND.
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**/
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BOOLEAN
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EFIAPI
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RdRand16Step (
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OUT UINT16 *Rand
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)
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{
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UINT8 Carry;
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//
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// Uses byte code for RDRAND instruction,
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// in case that GCC version has no direct support on RDRAND assembly.
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//
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__asm__ __volatile__ (
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".byte 0x66; .byte 0x0f; .byte 0xc7; .byte 0xf0; setc %1"
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:"=a" (*Rand),
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"=qm" (Carry)
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);
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return (BOOLEAN) Carry;
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}
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/**
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Generates a 32-bit random number through RDRAND instruction.
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@param[out] Rand Buffer pointer to store the random result.
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@retval TRUE RDRAND call was successful.
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@retval FALSE Failed attempts to call RDRAND.
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**/
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BOOLEAN
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EFIAPI
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RdRand32Step (
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OUT UINT32 *Rand
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)
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{
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UINT8 Carry;
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__asm__ __volatile__ (
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".byte 0x0f; .byte 0xc7; .byte 0xf0; setc %1"
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:"=a" (*Rand),
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"=qm" (Carry)
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);
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return (BOOLEAN) Carry;
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}
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/**
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Generates a 64-bit random number through RDRAND instruction.
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@param[out] Rand Buffer pointer to store the random result.
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@retval TRUE RDRAND call was successful.
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@retval FALSE Failed attempts to call RDRAND.
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**/
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BOOLEAN
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EFIAPI
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RdRand64Step (
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OUT UINT64 *Rand
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)
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{
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UINT8 Carry;
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__asm__ __volatile__ (
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".byte 0x48; .byte 0x0f; .byte 0xc7; .byte 0xf0; setc %1"
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:"=a" (*Rand),
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"=qm" (Carry)
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);
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return (BOOLEAN) Carry;
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}
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