MdeModulePkg/Variable: Add RT GetVariable() cache support

[mirror_edk2.git] / MdeModulePkg / MdeModulePkg.dec

diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index d6bac974da9513c6445b7531a4dff5f9d71b578f..3ef8fe7644d98d37775729b84b178287daa92913 100644 (file)
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -641,6 +641,18 @@
   # @Prompt Enable Device Path From Text support.\r
   gEfiMdeModulePkgTokenSpaceGuid.PcdDevicePathSupportDevicePathFromText|TRUE|BOOLEAN|0x00010038\r
 \r
+  ## Indicates if the UEFI variable runtime cache should be enabled.\r
+  #  This setting only applies if SMM variables are enabled. When enabled, all variable\r
+  #  data for Runtime Service GetVariable () and GetNextVariableName () calls is retrieved\r
+  #  from a runtime data buffer referred to as the "runtime cache". An SMI is not triggered\r
+  #  at all for these requests. Variables writes still trigger an SMI. This can greatly\r
+  #  reduce overall system SMM usage as most boots tend to issue far more variable reads\r
+  #  than writes.<BR><BR>\r
+  #   TRUE  - The UEFI variable runtime cache is enabled.<BR>\r
+  #   FALSE - The UEFI variable runtime cache is disabled.<BR>\r
+  # @Prompt Enable the UEFI variable runtime cache.\r
+  gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALSE|BOOLEAN|0x00010039\r
+\r
   ## Indicates if the statistics about variable usage will be collected. This information is\r
   #  stored as a vendor configuration table into the EFI system table.\r
   #  Set this PCD to TRUE to use VariableInfo application in MdeModulePkg\Application directory to get\r