[PATCH] PcAtChipsetPkg: Wrong System YEAR displayed in SETUP

[Yau <kaiyau@gmail.com>]

Function ConvertRtcTimeToEfiTime() will reset to Century 19XX when the year is set larger than the value of PcdMaximalValidYear outside SETUP.

Signed-off-by: Yau <kaix.yau@intel.com>
---
 PcAtChipsetPkg/PcAtChipsetPkg.dec             |  7 +++---
 .../PcatRealTimeClockRuntimeDxe/PcRtc.c       | 25 +++++++++++--------
 .../PcatRealTimeClockRuntimeDxe/PcRtc.h       | 17 +++++++------
 3 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/PcAtChipsetPkg/PcAtChipsetPkg.dec b/PcAtChipsetPkg/PcAtChipsetPkg.dec
index 88de5cceea..660cb5d52e 100644
--- a/PcAtChipsetPkg/PcAtChipsetPkg.dec
+++ b/PcAtChipsetPkg/PcAtChipsetPkg.dec
@@ -4,7 +4,7 @@
 # This package is designed to public interfaces and implementation which follows
 # PcAt defacto standard.
 #
-# Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2009 - 2020, Intel Corporation. All rights reserved.<BR>
 # Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
 #
 # SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -61,12 +61,13 @@
 
   ## This PCD specifies the minimal valid year in RTC.
   # @Prompt Minimal valid year in RTC.
-  gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear|1998|UINT16|0x0000000D
+  # @Expression 0x80000001 | gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear >= 2000
+  gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear|2000|UINT16|0x0000000D
 
   ## This PCD specifies the maximal valid year in RTC.
   # @Prompt Maximal valid year in RTC.
   # @Expression 0x80000001 | gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear < gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear + 100
-  gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear|2097|UINT16|0x0000000E
+  gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear|2099|UINT16|0x0000000E
 
 [PcdsFixedAtBuild, PcdsPatchableInModule]
   ## Defines the ACPI register set base address.
diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
index 52af179417..38a3521dfc 100644
--- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
+++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
@@ -1,7 +1,7 @@
 /** @file
   RTC Architectural Protocol GUID as defined in DxeCis 0.96.
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2020, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
 
 SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -441,8 +441,8 @@ PcRtcGetTime (
 **/
 EFI_STATUS
 PcRtcSetTime (
-  IN EFI_TIME                *Time,
-  IN PC_RTC_MODULE_GLOBALS   *Global
+  IN     EFI_TIME                *Time,
+  IN OUT PC_RTC_MODULE_GLOBALS   *Global
   )
 {
   EFI_STATUS      Status;
@@ -525,6 +525,8 @@ PcRtcSetTime (
   //
   if (Global->CenturyRtcAddress != 0) {
     RtcWrite (Global->CenturyRtcAddress, DecimalToBcd8 ((UINT8) (RtcTime.Year / 100)));
+  } else {
+    DEBUG ((EFI_D_INFO, "PcRtc: Century RTC Address is not found\n"));
   }
 
   ConvertEfiTimeToRtcTime (&RtcTime, RegisterB);
@@ -868,6 +870,9 @@ ConvertRtcTimeToEfiTime (
 {
   BOOLEAN IsPM;
   UINT8   Century;
+  UINT8   CenturyRtcAddress;
+
+  CenturyRtcAddress = GetCenturyRtcAddress ();
 
   if ((Time->Hour & 0x80) != 0) {
     IsPM = TRUE;
@@ -891,14 +896,12 @@ ConvertRtcTimeToEfiTime (
     return EFI_INVALID_PARAMETER;
   }
 
-  //
-  // For minimal/maximum year range [1970, 2069],
-  //   Century is 19 if RTC year >= 70,
-  //   Century is 20 otherwise.
-  //
-  Century = (UINT8) (PcdGet16 (PcdMinimalValidYear) / 100);
-  if (Time->Year < PcdGet16 (PcdMinimalValidYear) % 100) {
-    Century++;
+  if (CenturyRtcAddress != 0) {
+    Century = CheckAndConvertBcd8ToDecimal8 ((UINT8) (RtcRead (CenturyRtcAddress)));
+  } else if ((PcdGet16 (PcdMinimalValidYear) / 100) == (PcdGet16 (PcdMaximalValidYear) / 100)) {
+    Century = (UINT8)(PcdGet16 (PcdMinimalValidYear) / 100);
+  } else {
+    Century = RTC_INIT_CENTURY;
   }
   Time->Year = (UINT16) (Century * 100 + Time->Year);
 
diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
index 47293ce44c..94926fe73e 100644
--- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
+++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
@@ -1,7 +1,7 @@
 /** @file
   Header file for real time clock driver.
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2020, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
 
 SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -62,11 +62,12 @@ extern PC_RTC_MODULE_GLOBALS  mModuleGlobal;
 // Date and time initial values.
 // They are used if the RTC values are invalid during driver initialization
 //
-#define RTC_INIT_SECOND 0
-#define RTC_INIT_MINUTE 0
-#define RTC_INIT_HOUR   0
-#define RTC_INIT_DAY    1
-#define RTC_INIT_MONTH  1
+#define RTC_INIT_SECOND  0
+#define RTC_INIT_MINUTE  0
+#define RTC_INIT_HOUR    0
+#define RTC_INIT_DAY     1
+#define RTC_INIT_MONTH   1
+#define RTC_INIT_CENTURY 20
 
 #pragma pack(1)
 //
@@ -160,8 +161,8 @@ PcRtcInit (
 **/
 EFI_STATUS
 PcRtcSetTime (
-  IN EFI_TIME               *Time,
-  IN PC_RTC_MODULE_GLOBALS  *Global
+  IN     EFI_TIME               *Time,
+  IN OUT PC_RTC_MODULE_GLOBALS  *Global
   );
 
 /**
-- 
2.17.1.windows.2