UefiCpuPkg/DxeMpLib: Fix bug when getting target C-State from eax

[mirror_edk2.git] / UefiCpuPkg / Library / MpInitLib / X64 / MpFuncs.nasm

diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index f8f471233e15d0fe87edf9795cb150344d629ab7..34c07a6d51d2835b80fe00dc7facf775adfca82f 100644 (file)
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -266,8 +266,8 @@ MwaitLoop:
     xor        ecx, ecx           ; ecx = 0\r
     xor        edx, edx           ; edx = 0\r
     monitor\r
-    shl        ebx, 4\r
     mov        eax, ebx           ; Mwait Cx, Target C-State per eax[7:4]\r
+    shl        eax, 4\r
     mwait\r
     jmp        MwaitLoop\r
 HltLoop:\r