PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe: PcdRtcDefaultYear bounds

Add bounds checks of PcdRtcDefaultYear to guarantee that the year
is always between PcdMinimalValidYear and PcdMaximalValidYear.
This is required to make the following commit a backwards compatible
change and guarantee and invalid year is never set.

https://github.com/tianocore/edk2/commit/d55d73152ebf5c793b645d6ec5bc517d219881cd

This is required because use of an expression in the DEC file
PCD default value is only used to determine the DEC default values.
If an INF/DSC overrides PcdRtcDefaultYear, then the DEC expression
for PcdMinimalValidYear is not applied again.

Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
index b059e92f02..15759463f2 100644
--- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
+++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
@@ -317,7 +317,8 @@ PcRtcInit (
     Time.Hour       = RTC_INIT_HOUR;

     Time.Day        = RTC_INIT_DAY;

     Time.Month      = RTC_INIT_MONTH;

-    Time.Year       = PcdGet16 (PcdRtcDefaultYear);

+    Time.Year       = MAX (PcdGet16 (PcdRtcDefaultYear), PcdGet16 (PcdMinimalValidYear));

+    Time.Year       = MIN (Time.Year, PcdGet16 (PcdMaximalValidYear));

     Time.Nanosecond = 0;

     Time.TimeZone   = EFI_UNSPECIFIED_TIMEZONE;

     Time.Daylight   = 0;

@@ -357,7 +358,8 @@ PcRtcInit (
   Time.Hour       = RTC_INIT_HOUR;

   Time.Day        = RTC_INIT_DAY;

   Time.Month      = RTC_INIT_MONTH;

-  Time.Year       = PcdGet16 (PcdRtcDefaultYear);

+  Time.Year       = MAX (PcdGet16 (PcdRtcDefaultYear), PcdGet16 (PcdMinimalValidYear));

+  Time.Year       = MIN (Time.Year, PcdGet16 (PcdMaximalValidYear));

   Time.Nanosecond = 0;

   Time.TimeZone   = Global->SavedTimeZone;

   Time.Daylight   = Global->Daylight;