[edk2-platforms][PATCH 1/2] Platform/RPi/SmbiosDxe: Report a more human readable firmware revision

["Pete Batard" <pete@akeo.ie>]

The firmware revision that is queried through the VideoCore mailbox
is really the 32-bit timestamp of when the VideoCore firmware was
generated.

To make this more palatable for human reporting, convert it to a
YY.MM firmware revision, so that end-users can get an approximative
idea of how old their VideoCore firmware is.

Signed-off-by: Pete Batard <pete@akeo.ie>
---
 Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c   | 20 ++++++++++++--------
 Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.inf |  2 ++
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c b/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c
index 6aa68a0925ba..06c73d691f9d 100644
--- a/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c
+++ b/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.c
@@ -38,6 +38,7 @@
 #include <Library/PcdLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/MemoryAllocationLib.h>
+#include <Library/TimeBaseLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/PrintLib.h>
 
@@ -597,23 +598,26 @@ BIOSInfoUpdateSmbiosType0 (
   VOID
   )
 {
-  UINT32 FirmwareRevision = 0;
+  UINT32 EpochSeconds = 0;
   EFI_STATUS Status = EFI_SUCCESS;
+  EFI_TIME Time;
   INTN   i;
   INTN   State = 0;
   INTN   Value[2];
 
   // Populate the Firmware major and minor.
-  Status = mFwProtocol->GetFirmwareRevision (&FirmwareRevision);
+  Status = mFwProtocol->GetFirmwareRevision (&EpochSeconds);
   if (EFI_ERROR (Status)) {
     DEBUG ((DEBUG_ERROR, "Failed to get firmware revision: %r\n", Status));
   } else {
-    // This expects Broadcom / The Raspberry Pi Foundation to switch to
-    // less nonsensical VideoCore firmware revisions in the future...
-    mBIOSInfoType0.EmbeddedControllerFirmwareMajorRelease =
-      (UINT8)((FirmwareRevision >> 16) & 0xFF);
-    mBIOSInfoType0.EmbeddedControllerFirmwareMinorRelease =
-      (UINT8)(FirmwareRevision & 0xFF);
+    // The firmware revision is really an epoch time which we convert to a
+    // YY.MM major.minor. This is good enough for our purpose, where this
+    // revision is merely provided as a loose indicator of when the
+    // VideoCore firmware was generated.
+    EpochToEfiTime (EpochSeconds, &Time);
+    ASSERT (Time.Year >= 2000 && Time.Year <= 2255);
+    mBIOSInfoType0.EmbeddedControllerFirmwareMajorRelease = (UINT8)(Time.Year - 2000);
+    mBIOSInfoType0.EmbeddedControllerFirmwareMinorRelease = Time.Month;
   }
 
   // mBiosVendor and mBiosVersion, which are referenced in mBIOSInfoType0Strings,
diff --git a/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.inf b/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.inf
index 0bd72c3ba6a1..9554c2e998f1 100644
--- a/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.inf
+++ b/Platform/RaspberryPi/Drivers/PlatformSmbiosDxe/PlatformSmbiosDxe.inf
@@ -27,6 +27,7 @@ [Packages]
   ArmPlatformPkg/ArmPlatformPkg.dec
   ArmPkg/ArmPkg.dec
   Platform/RaspberryPi/RaspberryPi.dec
+  EmbeddedPkg/EmbeddedPkg.dec
 
 [LibraryClasses]
   UefiBootServicesTableLib
@@ -37,6 +38,7 @@ [LibraryClasses]
   UefiDriverEntryPoint
   DebugLib
   PrintLib
+  TimeBaseLib
 
 [Protocols]
   gEfiSmbiosProtocolGuid           # PROTOCOL SOMETIMES_CONSUMED
-- 
2.21.0.windows.1