1 files changed, 40 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseLib/Ia32/ReadCr4.c b/MdePkg/Library/BaseLib/Ia32/ReadCr4.c
new file mode 100644
index 000000000000..d12bf5cb55b7
--- /dev/null
+++ b/MdePkg/Library/BaseLib/Ia32/ReadCr4.c
@@ -0,0 +1,40 @@
+/** @file
+  AsmReadCr4 function
+
+  Copyright (c) 2006 - 2008, 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.
+
+**/
+
+
+
+
+/**
+  Reads the current value of the Control Register 4 (CR4).
+
+  Reads and returns the current value of CR4. This function is only available
+  on IA-32 and x64. This returns a 32-bit value on IA-32 and a 64-bit value on
+  x64.
+
+  @return The value of the Control Register 4 (CR4).
+
+**/
+UINTN
+EFIAPI
+AsmReadCr4 (
+  VOID
+  )
+{
+  __asm {
+    _emit  0x0f  // mov  eax, cr4
+    _emit  0x20
+    _emit  0xE0
+  }
+}
+