From 777034ce83a8ee4a13cda7c45524933459237595 Mon Sep 17 00:00:00 2001
From: Jiewen Yao <jiewen.yao@intel.com>
Date: Sat, 24 Dec 2016 00:00:51 +0800
Subject: [PATCH] MdeModulePkg/CapsuleLib: Support result rolling over.

According to UEFI spec, capsule result variable may roll over to 0.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Chao Zhang <chao.b.zhang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
---
 .../Library/DxeCapsuleLibFmp/DxeCapsuleReportLib.c       | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleReportLib.c b/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleReportLib.c
index 61ede5cfa9..ce79a5a619 100644
--- a/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleReportLib.c
+++ b/MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleReportLib.c
@@ -167,7 +167,7 @@ WriteNewCapsuleResultVariableCache (
   Get a new capsule status variable index.
 
   @return A new capsule status variable index.
-  @retval -1  No new capsule status variable index.
+  @retval 0  No new capsule status variable index. Rolling over.
 **/
 INTN
 GetNewCapsuleResultIndex (
@@ -178,7 +178,8 @@ GetNewCapsuleResultIndex (
 
   CurrentIndex = GetCurrentCapsuleLastIndex();
   if (CurrentIndex >= PcdGet16(PcdCapsuleMax)) {
-    return -1;
+    DEBUG((DEBUG_INFO, "  CapsuleResult variable Rolling Over!\n"));
+    return 0;
   }
 
   return CurrentIndex + 1;
@@ -206,9 +207,7 @@ WriteNewCapsuleResultVariable (
 
   CapsuleResultIndex = GetNewCapsuleResultIndex();
   DEBUG((DEBUG_INFO, "New CapsuleResultIndex - 0x%x\n", CapsuleResultIndex));
-  if (CapsuleResultIndex == -1) {
-    return EFI_OUT_OF_RESOURCES;
-  }
+
   UnicodeSPrint(
     CapsuleResultStr,
     sizeof(CapsuleResultStr),
-- 
2.39.2