1. Updated function headers in all assembly files.

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / ReadMsr64.asm

diff --git a/MdePkg/Library/BaseLib/X64/ReadMsr64.asm b/MdePkg/Library/BaseLib/X64/ReadMsr64.asm
index 4444c18676ea8a67e8eb77e9a70a9efc2be2ed0e..580c0761a4cfcc07a41e024bffc43034a8b62ea1 100644 (file)
--- a/MdePkg/Library/BaseLib/X64/ReadMsr64.asm
+++ b/MdePkg/Library/BaseLib/X64/ReadMsr64.asm
@@ -31,9 +31,9 @@
 ;   );\r
 ;------------------------------------------------------------------------------\r
 AsmReadMsr64    PROC\r
-    rdmsr\r
-    shl     rax, 20h\r
-    shrd    rax, rdx, 20h\r
+    rdmsr                               ; edx & eax are zero extended\r
+    shl     rdx, 20h\r
+    or      rax, rdx\r
     ret\r
 AsmReadMsr64    ENDP\r
 \r