Before the event callback, all the drivers(include SMM drivers) share the same
DXE SCRIPT_TABLE_PRIVATE_DATA instance, that means the instance pointed by
mS3BootScriptTablePtr.
After the event callback, all the SMM drivers share the same SMM
SCRIPT_TABLE_PRIVATE_DATA instance, that means the instance pointed by
mS3BootScriptTableSmmPtr, and mS3BootScriptTablePtr also updated to equal to
mS3BootScriptTableSmmPtr (in S3BootScriptSmmEventCallBack()).
And you may see the below code logic in S3BootScriptGetEntryAddAddress(), that
is to say only SMM driver is allowed to write boot script after the event
callback.
-------------------
if (mS3BootScriptTablePtr->AtRuntime) {
//
// We need check InSmm when AtRuntime, because after SmmReadyToLock, only
SMM driver is allowed to write boot script.
//
if (!mS3BootScriptTablePtr->InSmm) {
//
// Add DEBUG ERROR, so that we can find it at boot time.
// Do not use ASSERT, because we may have test invoke this interface.
//
DEBUG ((EFI_D_ERROR, "FATAL ERROR: Set boot script after
ReadyToLock!!!\n"));
return NULL;
}
-------------------
Thanks,
Star
From: Andrew Fish [mailto:af...@apple.com]
Sent: Wednesday, April 1, 2015 12:22 PM
To: edk2-devel@lists.sourceforge.net
Subject: Re: [edk2] MdeModulePkg Maintainer: The PiDxeS3BootScriptLib does not
seem to set EFI_BOOT_SCRIPT_TABLE_HEADER.Version
!mS3BootScriptTablePtr->AtRuntime
On Mar 31, 2015, at 8:44 PM, Zeng, Star
<star.z...@intel.com<mailto:star.z...@intel.com>> wrote:
i Andrew,
After SmmReadyToLock, only SMM driver is allowed to write boot script. In DXE
SCRIPT_TABLE_PRIVATE_DATA instance, only the TableBase field will be used for
BootScriptExecute at S3 resume, other fields will be not used.
So the TableLength field in DXE SCRIPT_TABLE_PRIVATE_DATA instance could be set
to 0 after SmmReadyToLock to say it will be not synced, or even the whole DXE
SCRIPT_TABLE_PRIVATE_DATA instance could be emptied as the TableBase field has
been saved into lockbox and will be restored at S3 resume.
I’m still confused on how it works? The 1st driver to run (DXE or SMM)
registers S3BootScriptEventCallBack() on gEfiDxeSmmReadyToLockProtocolGuid
event. If !mS3BootScriptTablePtr->AtRuntime then the LockBox is updated. In my
case this instance of the mS3BootScriptTablePtr had the incorrect length (too
short).
The SMM drivers all register S3BootScriptSmmEventCallBack() on the
gEfiSmmReadyToLockProtocolGuid event and this also calls
S3BootScriptEventCallBack (NULL, NULL).
It still seems like the LockBox is updated as part of the boot process (calling
the library APIs). S3BootScriptGetEntryAddAddress() calls
S3BootScriptGetBootTimeEntryAddAddress() and the DXE driver version of
SCRIPT_TABLE_PRIVATE_DATA. It seems if an SMM driver wrote a script entry,
prior to the event callback, things could get out os sync? Can you only call
the Library in SMM from locking events?
Thanks,
Andrew Fish
Thanks,
Star
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