mirror of https://github.com/acidanthera/audk.git
bd3afeb1d6
The RestoreLockBox() and RestoreAllLockBoxInPlace() functions handle the case when EFI_PEI_SMM_COMMUNICATION_PPI.Communicate() returns EFI_NOT_STARTED: they access the SMRAM directly, for restoring LockBox data. This occurs if a PEIM needs to restore LockBox data *before* the SMBASE is relocated and the SMI handler is installed for all processors. One such PEIM is UefiCpuPkg/Universal/Acpi/S3Resume2Pei. On the S3 resume path, in function S3RestoreConfig2(), LockBox data are restored *before* the SmmRestoreCpu() function of UefiCpuPkg/PiSmmCpuDxeSmm is called via SmmS3ResumeState->SmmS3ResumeEntryPoint. (The latter SmmRestoreCpu() function is responsible for the SMBASE relocation.) If a platform knows that its PEIMs restore LockBox data *only* before SMBASE relocation -- e.g., due to S3Resume2Pei being the platform's only SmmLockBoxPeiLib client --, then the platform might not want to include "UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationPei.inf" at all (hence not provide EFI_PEI_SMM_COMMUNICATION_PPI) -- because all of those restores would be serviced by direct SMRAM access anyway. Currently the absence of EFI_PEI_SMM_COMMUNICATION_PPI is not supported by SmmLockBoxPeiLib, but it's not hard to implement. Handle it the same as when EFI_PEI_SMM_COMMUNICATION_PPI.Communicate() returns EFI_NOT_STARTED: restore LockBox data directly from SMRAM. Suggested-by: Jiewen Yao <jiewen.yao@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Cc: Michael Kinney <michael.d.kinney@intel.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Jiewen Yao <jiewen.yao@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18823 6f19259b-4bc3-4df7-8a09-765794883524 |
||
|---|---|---|
| .. | ||
| SmmLockBoxDxeLib.c | ||
| SmmLockBoxDxeLib.inf | ||
| SmmLockBoxDxeLib.uni | ||
| SmmLockBoxLibPrivate.h | ||
| SmmLockBoxPeiLib.c | ||
| SmmLockBoxPeiLib.inf | ||
| SmmLockBoxPeiLib.uni | ||
| SmmLockBoxSmmLib.c | ||
| SmmLockBoxSmmLib.inf | ||
| SmmLockBoxSmmLib.uni | ||