UefiCpuPkg/CpuMpPei: Fix pack(1) issue on x64 arch

Packing alignment for MP_CPU_EXCHANGE_INFO should be 1. This should be typo when
check-in CpuMpPei driver. IA32 arch MP_CPU_EXCHANGE_INFO is luckly pack(1). It
leads CpuMpPei x64 version hung.

Contributed-under: TianoCore Contribution Agreement 1.0
Reported-by: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Tested-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19340 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.h b/UefiCpuPkg/CpuMpPei/CpuMpPei.h
index f2286b990ee9181b5377b5aece474e7ffbe96416..2b960c6eb1fe56d8f55c96ce68168f32684b24cb 100644 (file)
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.h
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.h
@@ -72,7 +72,7 @@ typedef struct {
 \r
 typedef struct _PEI_CPU_MP_DATA  PEI_CPU_MP_DATA;\r
 \r
-#pragma pack()\r
+#pragma pack(1)\r
 \r
 typedef union {\r
   struct {\r
@@ -95,6 +95,8 @@ typedef union {
 \r
 //\r
 // MP CPU exchange information for AP reset code\r
+// This structure is required to be packed because fixed field offsets\r
+// into this structure are used in assembly code in this module\r
 //\r
 typedef struct {\r
   UINTN                 Lock;\r