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| author | Ruiyu Ni <ruiyu.ni@intel.com> | 2018-05-25 17:00:16 +0800 |
|---|---|---|
| committer | Ruiyu Ni <ruiyu.ni@intel.com> | 2018-05-28 14:59:19 +0800 |
| commit | 60cb4d1b04b6334cf9d56eb95d135546053db1fd (patch) | |
| tree | 02a4f428ef7a40ad8cc21b4996ac60da3d03b413 /UefiCpuPkg/Library/CpuCommonFeaturesLib | |
| parent | 36dd3c781e204a97d548ce3595ef6f6b6337bc1f (diff) | |
| download | edk2-60cb4d1b04b6334cf9d56eb95d135546053db1fd.tar.gz edk2-60cb4d1b04b6334cf9d56eb95d135546053db1fd.tar.bz2 edk2-60cb4d1b04b6334cf9d56eb95d135546053db1fd.zip | |
UefiCpuPkg/CpuCommonFeatures: Follow SDM for MAX CPUID feature detect
According to IA manual:
"Before setting this bit (MSR_IA32_MISC_ENABLE[22]) , BIOS must
execute the CPUID.0H and examine the maximum value returned in
EAX[7:0]. If the maximum value is greater than 2, this bit is
supported."
We need to fix our current detection logic to compare against 2.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Cc: Ming Shao <ming.shao@intel.com>
Diffstat (limited to 'UefiCpuPkg/Library/CpuCommonFeaturesLib')
| -rw-r--r-- | UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c b/UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c index 40cc9d5fe0..3d41efe9e9 100644 --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c @@ -1,7 +1,7 @@ /** @file
LimitCpuidMaxval Feature.
- Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+ Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>
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
@@ -41,7 +41,7 @@ LimitCpuidMaxvalSupport ( UINT32 Eax;
AsmCpuid (CPUID_SIGNATURE, &Eax, NULL, NULL, NULL);
- return (Eax > 3);
+ return (Eax > 2);
}
/**
|