[edk2-devel] [PATCH] PcAtChipsetPkg: Wrong System YEAR displayed in SETUP

Yau, KaiX kaix.yau at intel.com
Mon Apr 27 05:47:20 UTC 2020


Hi Ray,

The current logic in PcRtc.c will give us WRONG year. (I explained below)
If we only change the PCD Min. value to 2000 and Max. value to 2099. The current logic will work. But we still have Y3K bug.

That is why we need to read from Hardware.
If any reasons you guys doesn't want to read from hardware, at least we need to change Min. and Max. value ASAP.
(you can go ahead to delete the change in PcRtc.c and just submit the PCD changes)

Regards
Kai Yau



-----------------------------------------------------------------------------
The root cause is from the following logic (PcRtc.c):

Current Default PcdMinimalValidYear = 1998
Current Default PcdMaximalValidYear = 2097

If we can set the YEAR to 2099, we will end up getting 1999 instead.   The reason why user have not found this problem because Windows does not allow user to set the YEAR to 2099. If we make the PcdMaximalValidYear  smaller, you can reproduce this issue. 

 Time->Year    = CheckAndConvertBcd8ToDecimal8 ((UINT8) Time->Year);   <-- Time->Year  = 99
  Century = (UINT8) (PcdGet16 (PcdMinimalValidYear) / 100);            <-- Century = 19
  if (Time->Year < PcdGet16 (PcdMinimalValidYear) % 100) {               <-- (99 < 97) = FALSE
    Century++;
  }
  Time->Year = (UINT16) (Century * 100 + Time->Year);                      <-- Time->Year = 1999  (19 x 100 + 99).       Also 1999 is within the RANGE, so it is considered as "VALID" data; however it is wrong.

Regards
Kai





-----Original Message-----
From: Ni, Ray 
Sent: Monday, April 27, 2020 12:54 AM
To: devel at edk2.groups.io; kaiyau at gmail.com
Cc: Yau, KaiX <kaix.yau at intel.com>; Jiang, Guomin <guomin.jiang at intel.com>; Gao, Liming <liming.gao at intel.com>
Subject: RE: [edk2-devel] [PATCH] PcAtChipsetPkg: Wrong System YEAR displayed in SETUP

This patch introduces several changes for different purposes.
At least I can see:
1. Default PCD value change
2. Consume century value from HW

Can you separate the patches to 2 patches?


For the purpose #2, can you explain more background/reason?

The PcdMinimalValidYear/ PcdMaximalValidYear value are chosen that when a two-digit year is read from HW, there is no confusion to convert to 4-digit year.
Are you aware of this when you made the patch?

Thanks,
Ray


> -----Original Message-----
> From: devel at edk2.groups.io <devel at edk2.groups.io> On Behalf Of Yau
> Sent: Friday, March 20, 2020 11:42 AM
> To: devel at edk2.groups.io
> Cc: Yau, KaiX <kaix.yau at intel.com>
> Subject: [edk2-devel] [PATCH] PcAtChipsetPkg: Wrong System YEAR 
> displayed in SETUP
> 
> 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 at 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|0x00000
> 00D
> +  # @Expression 0x80000001 |
> gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear >= 2000
> +
> gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear|2000|UINT16|0x00000
> 00D
> 
>    ## 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|0x00000
> 00E
> +
> gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear|2099|UINT16|0x00000
> 00E
> 
>  [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
> 
> 
> 


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