Kun: Seemly, PcdMaxVariableSize is not used by this module. It can be removed.
And, has its functionality been verified in the real platform? Thanks Liming > -----邮件原件----- > 发件人: devel@edk2.groups.io <devel@edk2.groups.io> 代表 Kun Qin > 发送时间: 2023年6月9日 4:45 > 收件人: devel@edk2.groups.io > 抄送: Hao A Wu <hao.a...@intel.com>; Liming Gao > <gaolim...@byosoft.com.cn>; Jian J Wang <jian.j.w...@intel.com>; Ronny > Hansen <hansen.ro...@microsoft.com>; Shriram Masanamuthu > Chinnathurai <shrira...@microsoft.com>; Preshit Harlikar > <pharli...@microsoft.com> > 主题: [edk2-devel] [PATCH v1 2/2] MdeModulePkg: Variable: Introduce MM > based variable read service in PEI > > From: Kun Qin <ku...@microsoft.com> > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4464 > > This change introduced the Standalone MM based variable read capability > in PEI phase for applicable platforms (such as ARM platforms). > > Similar to the x86 counterpart, MM communicate PPI is used to request > variable information from Standalone MM environment. > > Cc: Hao A Wu <hao.a...@intel.com> > Cc: Liming Gao <gaolim...@byosoft.com.cn> > Cc: Jian J Wang <jian.j.w...@intel.com> > > Co-authored-by: Ronny Hansen <hansen.ro...@microsoft.com> > Co-authored-by: Shriram Masanamuthu Chinnathurai > <shrira...@microsoft.com> > Co-authored-by: Preshit Harlikar <pharli...@microsoft.com> > Signed-off-by: Kun Qin <ku...@microsoft.com> > --- > MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.c | > 381 ++++++++++++++++++++ > MdeModulePkg/MdeModulePkg.dsc > | 1 + > MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.h | > 134 +++++++ > MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.inf | > 43 +++ > 4 files changed, 559 insertions(+) > > diff --git > a/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.c > b/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.c > new file mode 100644 > index 000000000000..4f937e22e89e > --- /dev/null > +++ b/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.c > @@ -0,0 +1,381 @@ > +/** @file -- MmVariablePei.c > > + Provides interface for reading Secure System Variables during PEI. > > + > > + Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR> > > + Copyright (c) Microsoft Corporation.<BR> > > + SPDX-License-Identifier: BSD-2-Clause-Patent > > +**/ > > + > > +#include "MmVariablePei.h" > > + > > +#define MM_VARIABLE_COMM_BUFFER_OFFSET > (SMM_COMMUNICATE_HEADER_SIZE + > SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) > > + > > +// > > +// Module globals > > +// > > +EFI_PEI_READ_ONLY_VARIABLE2_PPI mPeiSecureVariableRead = { > > + PeiMmGetVariable, > > + PeiMmGetNextVariableName > > +}; > > + > > +EFI_PEI_PPI_DESCRIPTOR mPeiMmVariablePpi = { > > + (EFI_PEI_PPI_DESCRIPTOR_PPI | > EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST), > > + &gEfiPeiReadOnlyVariable2PpiGuid, > > + &mPeiSecureVariableRead > > +}; > > + > > +/** > > + Entry point of PEI Secure Variable read driver > > + > > + @param FileHandle Handle of the file being invoked. > > + Type EFI_PEI_FILE_HANDLE is defined in > FfsFindNextFile(). > > + @param PeiServices General purpose services available to every > PEIM. > > + > > + @retval EFI_SUCCESS If the interface could be successfully installed > > + @retval Others Returned from PeiServicesInstallPpi() > > +**/ > > +EFI_STATUS > > +EFIAPI > > +PeiMmVariableInitialize ( > > + IN EFI_PEI_FILE_HANDLE FileHandle, > > + IN CONST EFI_PEI_SERVICES **PeiServices > > + ) > > +{ > > + return PeiServicesInstallPpi (&mPeiMmVariablePpi); > > +} > > + > > +/** > > + Helper function to populate MM communicate header and variable > communicate header > > + and then communicate to PEI. > > + > > + @param[in, out] CommunicateBuffer Size of the variable name. > > + @param[in] CommunicateBufferSize The entire buffer size to be > sent to MM. > > + @param[in] Function The MM variable function > value. > > + > > + @retval EFI_INVALID_PARAMETER Invalid parameter. > > + @retval EFI_SUCCESS Find the specified variable. > > + @retval Others Errors returned by MM > communicate or variable service. > > + > > +**/ > > +EFI_STATUS > > +PopulateHeaderAndCommunicate ( > > + IN OUT UINT8 *CommunicateBuffer, > > + IN UINTN CommunicateBufferSize, > > + IN UINTN Function > > + ) > > +{ > > + EFI_STATUS Status; > > + EFI_PEI_MM_COMMUNICATION_PPI *MmCommunicationPpi; > > + EFI_MM_COMMUNICATE_HEADER *MmCommunicateHeader; > > + SMM_VARIABLE_COMMUNICATE_HEADER *MmVarCommsHeader; > > + > > + // Minimal sanity check > > + if ((CommunicateBuffer == NULL) || > > + (CommunicateBufferSize < > MM_VARIABLE_COMM_BUFFER_OFFSET)) > > + { > > + Status = EFI_INVALID_PARAMETER; > > + DEBUG ((DEBUG_ERROR, "%a: Invalid incoming parameters: %p and > 0x%x\n", __func__, CommunicateBuffer, CommunicateBufferSize)); > > + goto Exit; > > + } > > + > > + if ((Function != > SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME) && > > + (Function != SMM_VARIABLE_FUNCTION_GET_VARIABLE)) > > + { > > + Status = EFI_INVALID_PARAMETER; > > + DEBUG ((DEBUG_ERROR, "%a: Invalid function value: 0x%x\n", > __func__, Function)); > > + goto Exit; > > + } > > + > > + Status = PeiServicesLocatePpi (&gEfiPeiMmCommunicationPpiGuid, 0, > NULL, (VOID **)&MmCommunicationPpi); > > + if (EFI_ERROR (Status)) { > > + DEBUG ((DEBUG_ERROR, "%a: Failed to locate PEI MM Communication > PPI: %r\n", __func__, Status)); > > + goto Exit; > > + } > > + > > + // Zero the entire Communication Buffer Header > > + MmCommunicateHeader = (EFI_MM_COMMUNICATE_HEADER > *)CommunicateBuffer; > > + > > + ZeroMem (MmCommunicateHeader, > SMM_COMMUNICATE_HEADER_SIZE); > > + > > + // Use gEfiSmmVariableProtocolGuid to request the MM variable service > in Standalone MM > > + CopyMem ((VOID *)&MmCommunicateHeader->HeaderGuid, > &gEfiSmmVariableProtocolGuid, sizeof (GUID)); > > + > > + // Program the MM header size > > + MmCommunicateHeader->MessageLength = CommunicateBufferSize - > SMM_COMMUNICATE_HEADER_SIZE; > > + > > + MmVarCommsHeader = (SMM_VARIABLE_COMMUNICATE_HEADER > *)(CommunicateBuffer + SMM_COMMUNICATE_HEADER_SIZE); > > + > > + // We are only supporting GetVariable and GetNextVariableName > > + MmVarCommsHeader->Function = Function; > > + > > + // Send the MM request using MmCommunicationPei > > + Status = MmCommunicationPpi->Communicate (MmCommunicationPpi, > CommunicateBuffer, &CommunicateBufferSize); > > + if (EFI_ERROR (Status)) { > > + // Received an error from MM interface. > > + DEBUG ((DEBUG_ERROR, "%a - MM Interface Error: %r\n", __func__, > Status)); > > + goto Exit; > > + } > > + > > + // MM request was successfully handled by the framework. > > + // Set status to the Variable Service Status Code > > + Status = MmVarCommsHeader->ReturnStatus; > > + if (EFI_ERROR (Status)) { > > + // We received an error from Variable Service. > > + // We cant do anymore so return Status > > + if (Status != EFI_BUFFER_TOO_SMALL) { > > + DEBUG ((DEBUG_ERROR, "%a - Variable Service Error: %r\n", > __func__, Status)); > > + } > > + > > + goto Exit; > > + } > > + > > +Exit: > > + return Status; > > +} > > + > > +/** > > + This service retrieves a variable's value using its name and GUID. > > + > > + This function is using the Secure Variable Store. If the Data > > + buffer is too small to hold the contents of the variable, the error > > + EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required > buffer > > + size to obtain the data. > > + > > + @param This A pointer to this instance of the > EFI_PEI_READ_ONLY_VARIABLE2_PPI. > > + @param VariableName A pointer to a null-terminated string > that is the variable's name. > > + @param VariableGuid A pointer to an EFI_GUID that is the > variable's GUID. The combination of > > + VariableGuid and VariableName > must be unique. > > + @param Attributes If non-NULL, on return, points to the > variable's attributes. > > + @param DataSize On entry, points to the size in bytes > of the Data buffer. > > + On return, points to the size of the > data returned in Data. > > + @param Data Points to the buffer which will hold > the returned variable value. > > + May be NULL with a zero DataSize in > order to determine the size of the buffer needed. > > + > > + @retval EFI_SUCCESS The variable was read successfully. > > + @retval EFI_NOT_FOUND The variable was not found. > > + @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the > resulting data. > > + DataSize is updated with the size > required for > > + the specified variable. > > + @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize > or Data is NULL. > > + @retval EFI_DEVICE_ERROR The variable could not be retrieved > because of a device error. > > + > > +**/ > > +EFI_STATUS > > +EFIAPI > > +PeiMmGetVariable ( > > + IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This, > > + IN CONST CHAR16 *VariableName, > > + IN CONST EFI_GUID *VariableGuid, > > + OUT UINT32 *Attributes, OPTIONAL > > + IN OUT UINTN *DataSize, > > + OUT VOID *Data OPTIONAL > > + ) > > +{ > > + EFI_STATUS Status; > > + UINTN MessageSize; > > + SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE > *MmVarAccessHeader; > > + UINT8 > *MmCommunicateBuffer; > > + UINTN RequiredPages; > > + > > + // Check input parameters > > + if ((VariableName == NULL) || (VariableGuid == NULL) || (DataSize == > NULL)) { > > + return EFI_INVALID_PARAMETER; > > + } > > + > > + if (VariableName[0] == 0) { > > + return EFI_NOT_FOUND; > > + } > > + > > + if ((*DataSize > 0) && (Data == NULL)) { > > + return EFI_INVALID_PARAMETER; > > + } > > + > > + // Allocate required pages to send MM request > > + MessageSize = MM_VARIABLE_COMM_BUFFER_OFFSET + > > + OFFSET_OF > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) + > > + StrSize (VariableName) + *DataSize; > > + > > + RequiredPages = EFI_SIZE_TO_PAGES (MessageSize); > > + MmCommunicateBuffer = (UINT8 *)AllocatePages (RequiredPages); > > + > > + if (MmCommunicateBuffer == NULL) { > > + Status = EFI_OUT_OF_RESOURCES; > > + DEBUG ((DEBUG_ERROR, "%a: Failed to allocate memory: %r\n", > __func__, Status)); > > + return Status; > > + } > > + > > + // Zero the entire Communication Buffer > > + ZeroMem (MmCommunicateBuffer, (RequiredPages * EFI_PAGE_SIZE)); > > + > > + // > > + // Program all payload structure contents > > + // > > + MmVarAccessHeader = > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE > *)(MmCommunicateBuffer + MM_VARIABLE_COMM_BUFFER_OFFSET); > > + > > + // Variable GUID > > + CopyMem ((VOID *)&MmVarAccessHeader->Guid, VariableGuid, sizeof > (GUID)); > > + > > + // Program the max amount of data we accept. > > + MmVarAccessHeader->DataSize = *DataSize; > > + > > + // Get size of the variable name > > + MmVarAccessHeader->NameSize = StrSize (VariableName); > > + > > + // Populate incoming variable name > > + CopyMem ((VOID *)&MmVarAccessHeader->Name, VariableName, > MmVarAccessHeader->NameSize); > > + > > + Status = PopulateHeaderAndCommunicate (MmCommunicateBuffer, > MessageSize, SMM_VARIABLE_FUNCTION_GET_VARIABLE); > > + if (EFI_ERROR (Status)) { > > + // We received an error from either communicate or Variable Service. > > + if (Status != EFI_BUFFER_TOO_SMALL) { > > + DEBUG ((DEBUG_ERROR, "%a - Communite to MM for variable > service errored: %r\n", __func__, Status)); > > + } > > + > > + goto Exit; > > + } > > + > > + Status = EFI_SUCCESS; > > + > > + // User provided buffer is too small > > + if (*DataSize < MmVarAccessHeader->DataSize) { > > + Status = EFI_BUFFER_TOO_SMALL; > > + } > > + > > +Exit: > > + // Check if we need to set Attributes > > + if (Attributes != NULL) { > > + *Attributes = MmVarAccessHeader->Attributes; > > + } > > + > > + *DataSize = MmVarAccessHeader->DataSize; > > + > > + if (Status == EFI_SUCCESS) { > > + CopyMem ((VOID *)Data, (UINT8 *)MmVarAccessHeader->Name + > MmVarAccessHeader->NameSize, *DataSize); > > + } > > + > > + // Free the Communication Buffer > > + if (MmCommunicateBuffer != NULL) { > > + FreePages (MmCommunicateBuffer, RequiredPages); > > + } > > + > > + return Status; > > +} > > + > > +/** > > + Return the next variable name and GUID. > > + > > + This function is called multiple times to retrieve the VariableName > > + and VariableGuid of all variables currently available in the system. > > + On each call, the previous results are passed into the interface, > > + and, on return, the interface returns the data for the next > > + interface. When the entire variable list has been returned, > > + EFI_NOT_FOUND is returned. > > + > > + @param This A pointer to this instance of the > EFI_PEI_READ_ONLY_VARIABLE2_PPI. > > + > > + @param VariableNameSize On entry, points to the size of the buffer > pointed to by VariableName. > > + On return, the size of the variable name > buffer. > > + @param VariableName On entry, a pointer to a null-terminated > string that is the variable's name. > > + On return, points to the next variable's > null-terminated name string. > > + > > + @param VariableGuid On entry, a pointer to an EFI_GUID that is > the variable's GUID. > > + On return, a pointer to the next variable's > GUID. > > + > > + @retval EFI_SUCCESS The variable was read successfully. > > + @retval EFI_NOT_FOUND The variable could not be found. > > + @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small > for the resulting > > + data. VariableNameSize is updated > with the size > > + required for the specified variable. > > + @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or > > + VariableNameSize is NULL. > > + @retval EFI_DEVICE_ERROR The variable could not be retrieved > because of a device error. > > +**/ > > +EFI_STATUS > > +EFIAPI > > +PeiMmGetNextVariableName ( > > + IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This, > > + IN OUT UINTN *VariableNameSize, > > + IN OUT CHAR16 *VariableName, > > + IN OUT EFI_GUID *VariableGuid > > + ) > > +{ > > + EFI_STATUS Status; > > + UINTN > MessageSize; > > + UINT8 > *MmCommunicateBuffer; > > + SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME > *MmVarGetNextVarHeader; > > + UINTN > RequiredPages; > > + > > + // Check input parameters > > + if ((VariableName == NULL) || > > + (VariableGuid == NULL) || > > + (VariableNameSize == NULL) || > > + (*VariableNameSize == 0)) > > + { > > + return EFI_INVALID_PARAMETER; > > + } > > + > > + // Allocate required pages to send MM request > > + MessageSize = MM_VARIABLE_COMM_BUFFER_OFFSET + > > + OFFSET_OF > (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) + > > + StrSize (VariableName) + *VariableNameSize; > > + > > + RequiredPages = EFI_SIZE_TO_PAGES (MessageSize); > > + MmCommunicateBuffer = (UINT8 *)AllocatePages (RequiredPages); > > + > > + if (MmCommunicateBuffer == NULL) { > > + Status = EFI_OUT_OF_RESOURCES; > > + DEBUG ((DEBUG_ERROR, "%a: Failed to allocate memory: %r\n", > __func__, Status)); > > + return Status; > > + } > > + > > + // Zero the entire Communication Buffer > > + ZeroMem (MmCommunicateBuffer, (RequiredPages * EFI_PAGE_SIZE)); > > + > > + // > > + // Program all payload structure contents > > + // > > + MmVarGetNextVarHeader = > (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME > *)(MmCommunicateBuffer + MM_VARIABLE_COMM_BUFFER_OFFSET); > > + > > + // Variable GUID > > + CopyMem ((VOID *)&MmVarGetNextVarHeader->Guid, VariableGuid, > sizeof (GUID)); > > + > > + // Program the maximal length of name we can accept. > > + MmVarGetNextVarHeader->NameSize = *VariableNameSize; > > + > > + // Populate incoming variable name > > + CopyMem ((VOID *)&MmVarGetNextVarHeader->Name, VariableName, > MmVarGetNextVarHeader->NameSize); > > + > > + // Send the MM request using MmCommunicationPei > > + Status = PopulateHeaderAndCommunicate (MmCommunicateBuffer, > MessageSize, SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME); > > + if (EFI_ERROR (Status)) { > > + // We received an error from either communicate or Variable Service. > > + if (Status != EFI_BUFFER_TOO_SMALL) { > > + DEBUG ((DEBUG_ERROR, "%a - Communite to MM for variable > service errored: %r\n", __func__, Status)); > > + } > > + > > + goto Exit; > > + } > > + > > + Status = EFI_SUCCESS; > > + > > + // User provided buffer is too small > > + if (*VariableNameSize < MmVarGetNextVarHeader->NameSize) { > > + Status = EFI_BUFFER_TOO_SMALL; > > + } > > + > > +Exit: > > + // Update the name size to be returned > > + *VariableNameSize = MmVarGetNextVarHeader->NameSize; > > + > > + if (Status == EFI_SUCCESS) { > > + CopyMem ((VOID *)VariableName, (UINT8 > *)MmVarGetNextVarHeader->Name, *VariableNameSize); > > + CopyMem ((VOID *)VariableGuid, (UINT8 > *)&(MmVarGetNextVarHeader->Guid), sizeof (EFI_GUID)); > > + } > > + > > + // Free the Communication Buffer > > + if (MmCommunicateBuffer != NULL) { > > + FreePages (MmCommunicateBuffer, RequiredPages); > > + } > > + > > + return Status; > > +} > > diff --git a/MdeModulePkg/MdeModulePkg.dsc > b/MdeModulePkg/MdeModulePkg.dsc > index 5b1f50e9c084..1aedfe280ae1 100644 > --- a/MdeModulePkg/MdeModulePkg.dsc > +++ b/MdeModulePkg/MdeModulePkg.dsc > @@ -400,6 +400,7 @@ [Components] > MdeModulePkg/Application/VariableInfo/VariableInfo.inf > > > MdeModulePkg/Universal/FaultTolerantWritePei/FaultTolerantWritePei.inf > > MdeModulePkg/Universal/Variable/Pei/VariablePei.inf > > + MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.inf > > MdeModulePkg/Universal/WatchdogTimerDxe/WatchdogTimer.inf > > MdeModulePkg/Universal/TimestampDxe/TimestampDxe.inf > > > MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.inf > > diff --git > a/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.h > b/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.h > new file mode 100644 > index 000000000000..0feed8cd1cb6 > --- /dev/null > +++ b/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.h > @@ -0,0 +1,134 @@ > +/** @file -- MmVariablePei.h > > + Provides interface for reading Secure System Variables during PEI. > > + > > + Copyright (c) Microsoft Corporation. > > + SPDX-License-Identifier: BSD-2-Clause-Patent > > +**/ > > + > > +#ifndef PEI_MM_VARIABLE_LIB_H_ > > +#define PEI_MM_VARIABLE_LIB_H_ > > + > > +#include <PiPei.h> > > +#include <Uefi/UefiSpec.h> > > + > > +#include <Library/DebugLib.h> > > +#include <Library/PcdLib.h> > > +#include <Library/BaseMemoryLib.h> > > +#include <Library/PeimEntryPoint.h> > > +#include <Library/PeiServicesLib.h> > > +#include <Library/MemoryAllocationLib.h> > > +#include <Library/HobLib.h> > > + > > +#include <Guid/SmmVariableCommon.h> > > + > > +#include <Ppi/ReadOnlyVariable2.h> > > +#include <Ppi/MmCommunication.h> > > + > > +#include <Protocol/SmmVariable.h> > > +#include <Protocol/MmCommunication.h> > > + > > +/** > > + Entry point of PEI Secure Variable read driver > > + > > + @param FileHandle Handle of the file being invoked. > > + Type EFI_PEI_FILE_HANDLE is defined in > FfsFindNextFile(). > > + @param PeiServices General purpose services available to every > PEIM. > > + > > + @retval EFI_SUCCESS If the interface could be successfully installed > > + @retval Others Returned from PeiServicesInstallPpi() > > +**/ > > +EFI_STATUS > > +EFIAPI > > +PeiMmVariableInitialize ( > > + IN EFI_PEI_FILE_HANDLE FileHandle, > > + IN CONST EFI_PEI_SERVICES **PeiServices > > + ); > > + > > +/** > > + > > + This function enables the read of Secure Variables during PEI. > > + > > + This function is using the Secure Variable Store.If the Data > > + buffer is too small to hold the contents of the variable, the error > > + EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required > buffer > > + size to obtain the data. > > + > > + The function performs the following: > > + > > + 1) Creates an MM request > > + 2) Fills out the following data structures for the Secure Variable Service > > + > SMM_VARIABLE_COMMUNICATE_HEADER/SMM_VARIABLE_COMMUNICAT > E_ACCESS_VARIABLE > > + 3) Adds the MM data structures to the MM request. > > + 4) Sends the MM request to EL3 using MmCommunicationPeiLib. > > + 5) The MM request is sent to S-EL0. > > + 6) The MM request is then handled by the registered handler with GUID: > gEfiSmmVariableProtocolGuid > > + > > + @param This A pointer to this instance of the > EFI_PEI_READ_ONLY_VARIABLE2_PPI. > > + @param VariableName A pointer to a null-terminated string > that is the variable's name. > > + @param VariableGuid A pointer to an EFI_GUID that is the > variable's GUID. The combination of > > + VariableGuid and VariableName > must be unique. > > + @param Attributes If non-NULL, on return, points to the > variable's attributes. > > + @param DataSize On entry, points to the size in bytes > of the Data buffer. > > + On return, points to the size of the > data returned in Data. > > + @param Data Points to the buffer which will hold > the returned variable value. > > + May be NULL with a zero DataSize in > order to determine the size of the buffer needed. > > + > > + @retval EFI_SUCCESS The variable was read successfully. > > + @retval EFI_NOT_FOUND The variable was not found. > > + @retval EFI_BUFFER_TOO_SMALL The DataSize is too small for the > resulting data. > > + DataSize is updated with the size > required for > > + the specified variable. > > + @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize > or Data is NULL. > > + @retval EFI_DEVICE_ERROR The variable could not be retrieved > because of a device error. > > + > > +**/ > > +EFI_STATUS > > +EFIAPI > > +PeiMmGetVariable ( > > + IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This, > > + IN CONST CHAR16 *VariableName, > > + IN CONST EFI_GUID *VariableGuid, > > + OUT UINT32 *Attributes, > > + IN OUT UINTN *DataSize, > > + OUT VOID *Data OPTIONAL > > + ); > > + > > +/** > > + Return the next variable name and GUID. > > + > > + This function is called multiple times to retrieve the VariableName > > + and VariableGuid of all variables currently available in the system. > > + On each call, the previous results are passed into the interface, > > + and, on return, the interface returns the data for the next > > + interface. When the entire variable list has been returned, > > + EFI_NOT_FOUND is returned. > > + > > + @param This A pointer to this instance of the > EFI_PEI_READ_ONLY_VARIABLE2_PPI. > > + > > + @param VariableNameSize On entry, points to the size of the buffer > pointed to by VariableName. > > + On return, the size of the variable name > buffer. > > + @param VariableName On entry, a pointer to a null-terminated > string that is the variable's name. > > + On return, points to the next variable's > null-terminated name string. > > + > > + @param VariableGuid On entry, a pointer to an EFI_GUID that is > the variable's GUID. > > + On return, a pointer to the next variable's > GUID. > > + > > + @retval EFI_SUCCESS The variable was read successfully. > > + @retval EFI_NOT_FOUND The variable could not be found. > > + @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small > for the resulting > > + data. VariableNameSize is updated > with the size > > + required for the specified variable. > > + @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or > > + VariableNameSize is NULL. > > + @retval EFI_DEVICE_ERROR The variable could not be retrieved > because of a device error. > > +**/ > > +EFI_STATUS > > +EFIAPI > > +PeiMmGetNextVariableName ( > > + IN CONST EFI_PEI_READ_ONLY_VARIABLE2_PPI *This, > > + IN OUT UINTN *VariableNameSize, > > + IN OUT CHAR16 *VariableName, > > + IN OUT EFI_GUID *VariableGuid > > + ); > > + > > +#endif /* PEI_MM_VARIABLE_LIB_H_ */ > > diff --git > a/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.inf > b/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.inf > new file mode 100644 > index 000000000000..d122703e9b5d > --- /dev/null > +++ b/MdeModulePkg/Universal/Variable/MmVariablePei/MmVariablePei.inf > @@ -0,0 +1,43 @@ > +## @file -- MmVariablePei.inf > > +# Provides interface for reading Secure System Variables during PEI. > > +# > > +# Copyright (c) Microsoft Corporation. > > +# SPDX-License-Identifier: BSD-2-Clause-Patent > > +## > > + > > + > > +[Defines] > > + INF_VERSION = 0x00010005 > > + BASE_NAME = MmVariablePei > > + FILE_GUID = > CD660A87-454B-4346-A35C-3D89BF8ECFAF > > + MODULE_TYPE = PEIM > > + VERSION_STRING = 1.0 > > + ENTRY_POINT = PeiMmVariableInitialize > > + > > +[Sources] > > + MmVariablePei.c > > + MmVariablePei.h > > + > > +[Packages] > > + MdePkg/MdePkg.dec > > + MdeModulePkg/MdeModulePkg.dec > > + > > +[LibraryClasses] > > + PcdLib > > + PeiServicesLib > > + PeimEntryPoint > > + MemoryAllocationLib > > + HobLib > > + > > +[Pcd] > > + gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize > > + > > +[Protocols] > > + gEfiSmmVariableProtocolGuid ## CONSUMES > > + > > +[Ppis] > > + gEfiPeiReadOnlyVariable2PpiGuid ## PRODUCES > > + gEfiPeiMmCommunicationPpiGuid ## CONSUMES > > + > > +[Depex] > > + gEfiPeiMmCommunicationPpiGuid > > -- > 2.40.1.windows.1 > > > > -=-=-=-=-=-= > Groups.io Links: You receive all messages sent to this group. > View/Reply Online (#105956): > https://edk2.groups.io/g/devel/message/105956 > Mute This Topic: https://groups.io/mt/99415826/4905953 > Group Owner: devel+ow...@edk2.groups.io > Unsubscribe: https://edk2.groups.io/g/devel/unsub > [gaolim...@byosoft.com.cn] > -=-=-=-=-=-= > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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