In the next patch we'll add a driver that exposes the SMM System
Management System Table (normally only accessible in SMM) to the world.
For this purpose we allocate a PCD called PcdDiscloseSmstPtrPtr that
contains a pointer to the pointer to the SMST.
PCD value, pointer to
lost at warm ---> SMST in runtime ---> SMST: also survives
reboot but storage:
recreated survives warm
with same reboot
value (reallocated
in same spot)
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
---
OvmfPkg/PlatformPei/PlatformPei.inf | 1 +
OvmfPkg/PlatformPei/Platform.c | 4 ++++
OvmfPkg/OvmfPkg.dec | 5 +++++
3 files changed, 10 insertions(+)
diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf
b/OvmfPkg/PlatformPei/PlatformPei.inf
index 8811542..028a640 100644
--- a/OvmfPkg/PlatformPei/PlatformPei.inf
+++ b/OvmfPkg/PlatformPei/PlatformPei.inf
@@ -63,6 +63,7 @@
gUefiOvmfPkgTokenSpaceGuid.PcdAcpiPmBaseAddress
gUefiOvmfPkgTokenSpaceGuid.PcdEmuSmmAreaSize
gUefiOvmfPkgTokenSpaceGuid.PcdEmuSmmAreaBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdDiscloseSmstPtrPtr
gEfiMdeModulePkgTokenSpaceGuid.PcdVariableStoreSize
gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize
gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize
diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c
index 4bce240..2616757 100644
--- a/OvmfPkg/PlatformPei/Platform.c
+++ b/OvmfPkg/PlatformPei/Platform.c
@@ -393,6 +393,10 @@ ReserveEmuSmmArea (
Address = AllocateRuntimePool (AreaSize);
ASSERT (Address != NULL);
PcdSet64 (PcdEmuSmmAreaBase, (UINT64)(UINTN) Address);
+
+ Address = AllocateRuntimePool (sizeof (UINT64));
+ ASSERT (Address != NULL);
+ PcdSet64 (PcdDiscloseSmstPtrPtr, (UINT64)(UINTN) Address);
}
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 21105ad..cfc0fc3 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -94,5 +94,10 @@
# bitnesses.
gUefiOvmfPkgTokenSpaceGuid.PcdEmuSmmAreaBase|0x0|UINT64|0x12
+ ## The DiscloseSmstSmm SMM driver stores the address of the System Management
+ # System Table in the location pointed to by this PCD. The EmuSmmPei PEIM
+ # fetches the SMST address from the same location.
+ gUefiOvmfPkgTokenSpaceGuid.PcdDiscloseSmstPtrPtr|0x0|UINT64|0x13
+
[PcdsFeatureFlag]
gUefiOvmfPkgTokenSpaceGuid.PcdSecureBootEnable|FALSE|BOOLEAN|3
--
1.8.3.1
------------------------------------------------------------------------------
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