1 files changed, 74 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/BaseLib/Ia32/CpuId.c b/Core/MdePkg/Library/BaseLib/Ia32/CpuId.c
new file mode 100644
index 0000000000..09487f77f2
--- /dev/null
+++ b/Core/MdePkg/Library/BaseLib/Ia32/CpuId.c
@@ -0,0 +1,74 @@
+/** @file
+  AsmCpuid function.
+
+  Copyright (c) 2006 - 2010, 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
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+/**
+  Retrieves CPUID information.
+
+  Executes the CPUID instruction with EAX set to the value specified by Index.
+  This function always returns Index.
+  If Eax is not NULL, then the value of EAX after CPUID is returned in Eax.
+  If Ebx is not NULL, then the value of EBX after CPUID is returned in Ebx.
+  If Ecx is not NULL, then the value of ECX after CPUID is returned in Ecx.
+  If Edx is not NULL, then the value of EDX after CPUID is returned in Edx.
+  This function is only available on IA-32 and x64.
+
+  @param  Index         The 32-bit value to load into EAX prior to invoking the CPUID
+                        instruction.
+  @param  RegisterEax   A pointer to the 32-bit EAX value returned by the CPUID
+                        instruction. This is an optional parameter that may be NULL.
+  @param  RegisterEbx   A pointer to the 32-bit EBX value returned by the CPUID
+                        instruction. This is an optional parameter that may be NULL.
+  @param  RegisterEcx   A pointer to the 32-bit ECX value returned by the CPUID
+                        instruction. This is an optional parameter that may be NULL.
+  @param  RegisterEdx   A pointer to the 32-bit EDX value returned by the CPUID
+                        instruction. This is an optional parameter that may be NULL.
+
+  @return Index.
+
+**/
+UINT32
+EFIAPI
+AsmCpuid (
+  IN      UINT32                    Index,
+  OUT     UINT32                    *RegisterEax,  OPTIONAL
+  OUT     UINT32                    *RegisterEbx,  OPTIONAL
+  OUT     UINT32                    *RegisterEcx,  OPTIONAL
+  OUT     UINT32                    *RegisterEdx   OPTIONAL
+  )
+{
+  _asm {
+    mov     eax, Index
+    cpuid
+    push    ecx
+    mov     ecx, RegisterEax
+    jecxz   SkipEax
+    mov     [ecx], eax
+SkipEax:
+    mov     ecx, RegisterEbx
+    jecxz   SkipEbx
+    mov     [ecx], ebx
+SkipEbx:
+    pop     eax
+    mov     ecx, RegisterEcx
+    jecxz   SkipEcx
+    mov     [ecx], eax
+SkipEcx:
+    mov     ecx, RegisterEdx
+    jecxz   SkipEdx
+    mov     [ecx], edx
+SkipEdx:
+    mov     eax, Index
+  }
+}
+