diff options
| -rw-r--r-- | UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c | 7 | ||||
| -rw-r--r-- | UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c | 7 |
2 files changed, 10 insertions, 4 deletions
diff --git a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c index 4064049807..f81bbb2252 100644 --- a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c +++ b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c @@ -314,12 +314,15 @@ GetInitialApicId ( //
// If CPUID Leaf B is supported,
+ // And CPUID.0BH:EBX[15:0] reports a non-zero value,
// Then the initial 32-bit APIC ID = CPUID.0BH:EDX
// Else the initial 8-bit APIC ID = CPUID.1:EBX[31:24]
//
if (MaxCpuIdIndex >= CPUID_EXTENDED_TOPOLOGY) {
- AsmCpuidEx (CPUID_EXTENDED_TOPOLOGY, 0, NULL, NULL, NULL, &ApicId);
- return ApicId;
+ AsmCpuidEx (CPUID_EXTENDED_TOPOLOGY, 0, NULL, &RegEbx, NULL, &ApicId);
+ if ((RegEbx & (BIT16 - 1)) != 0) {
+ return ApicId;
+ }
}
AsmCpuid (CPUID_VERSION_INFO, NULL, &RegEbx, NULL, NULL);
diff --git a/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c b/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c index 9720d26e60..e690d2aa14 100644 --- a/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c +++ b/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c @@ -411,12 +411,15 @@ GetInitialApicId ( AsmCpuid (CPUID_SIGNATURE, &MaxCpuIdIndex, NULL, NULL, NULL);
//
// If CPUID Leaf B is supported,
+ // And CPUID.0BH:EBX[15:0] reports a non-zero value,
// Then the initial 32-bit APIC ID = CPUID.0BH:EDX
// Else the initial 8-bit APIC ID = CPUID.1:EBX[31:24]
//
if (MaxCpuIdIndex >= CPUID_EXTENDED_TOPOLOGY) {
- AsmCpuidEx (CPUID_EXTENDED_TOPOLOGY, 0, NULL, NULL, NULL, &ApicId);
- return ApicId;
+ AsmCpuidEx (CPUID_EXTENDED_TOPOLOGY, 0, NULL, &RegEbx, NULL, &ApicId);
+ if ((RegEbx & (BIT16 - 1)) != 0) {
+ return ApicId;
+ }
}
AsmCpuid (CPUID_VERSION_INFO, NULL, &RegEbx, NULL, NULL);
return RegEbx >> 24;
|