| /** @file |
| EDKII PEI Variable PPI provides an implementation of variables |
| intended for use as a means to store data in the PEI environment. |
| |
| Copyright (c) 2022, Intel Corporation. All rights reserved.<BR> |
| SPDX-License-Identifier: BSD-2-Clause-Patent |
| |
| **/ |
| |
| #ifndef EDKII_PEI_VARIABLE_PPI_H_ |
| #define EDKII_PEI_VARIABLE_PPI_H_ |
| |
| #define EDKII_PEI_VARIABLE_PPI_GUID \ |
| { \ |
| 0xe7b2cd04, 0x4b14, 0x44c2, { 0xb7, 0x48, 0xce, 0xaf, 0x2b, 0x66, 0x4a, 0xb0 } \ |
| } |
| |
| typedef struct _EDKII_PEI_VARIABLE_PPI EDKII_PEI_VARIABLE_PPI; |
| |
| /** |
| This service retrieves a variable's value using its name and GUID. |
| |
| Read the specified variable from the UEFI 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[in] This A pointer to this instance of the EDKII_PEI_VARIABLE_PPI. |
| @param[in] VariableName A pointer to a null-terminated string that is the variable's name. |
| @param[in] VariableGuid A pointer to an EFI_GUID that is the variable's GUID. The combination of |
| VariableGuid and VariableName must be unique. |
| @param[out] Attributes If non-NULL, on return, points to the variable's attributes. |
| @param[in, out] 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[out] 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. |
| |
| **/ |
| typedef |
| EFI_STATUS |
| (EFIAPI *EDKII_PEI_GET_VARIABLE)( |
| IN CONST EDKII_PEI_VARIABLE_PPI *This, |
| IN CONST CHAR16 *VariableName, |
| IN CONST EFI_GUID *VariableGuid, |
| OUT UINT32 *Attributes OPTIONAL, |
| 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 |
| variable. To get started, VariableName should initially contain L"\0" |
| and VariableNameSize should be sizeof(CHAR16). When the entire |
| variable list has been returned, EFI_NOT_FOUND is returned. |
| |
| @param[in] This A pointer to this instance of the EDKII_PEI_VARIABLE_PPI. |
| @param[in, out] VariableNameSize On entry, points to the size of the buffer pointed to by VariableName. |
| On return, the size of the variable name buffer. |
| @param[in, out] 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[in, out] 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 next variable name was read successfully. |
| @retval EFI_NOT_FOUND All variables have been enumerated. |
| @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. |
| |
| **/ |
| typedef |
| EFI_STATUS |
| (EFIAPI *EDKII_PEI_GET_NEXT_VARIABLE_NAME)( |
| IN CONST EDKII_PEI_VARIABLE_PPI *This, |
| IN OUT UINTN *VariableNameSize, |
| IN OUT CHAR16 *VariableName, |
| IN OUT EFI_GUID *VariableGuid |
| ); |
| |
| /** |
| Sets the value of a variable. |
| |
| @param[in] This A pointer to this instance of the EDKII_PEI_VARIABLE_PPI. |
| @param[in] VariableName A Null-terminated string that is the name of the vendor's variable. |
| Each VariableName is unique for each VendorGuid. VariableName must |
| contain 1 or more characters. If VariableName is an empty string, |
| then EFI_INVALID_PARAMETER is returned. |
| @param[in] VendorGuid A unique identifier for the vendor. |
| @param[in] Attributes Attributes bitmask to set for the variable. |
| @param[in] DataSize The size in bytes of the Data buffer. Unless the EFI_VARIABLE_APPEND_WRITE |
| attribute is set, a size of zero causes the variable to be deleted. When the |
| EFI_VARIABLE_APPEND_WRITE attribute is set, then a SetVariable() call with a |
| DataSize of zero will not cause any change to the variable value. |
| @param[in] Data The contents for the variable. |
| |
| @retval EFI_SUCCESS The firmware has successfully stored the variable and its data as |
| defined by the Attributes. |
| @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits, name, and GUID was supplied, or the |
| DataSize exceeds the maximum allowed. |
| @retval EFI_INVALID_PARAMETER VariableName is an empty string. |
| @retval EFI_OUT_OF_RESOURCES Not enough storage is available to hold the variable and its data. |
| @retval EFI_DEVICE_ERROR The variable could not be stored due to a hardware error. |
| @retval EFI_WRITE_PROTECTED The variable in question is read-only. |
| @retval EFI_WRITE_PROTECTED The variable in question cannot be deleted. |
| @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, |
| or EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, or |
| EFI_VARIABLE_ENHANCED_AUTHENTICATED_ACCESS being set. Writing to authenticated |
| variables is not supported in the PEI environment. Updates to authenticated |
| variables can be requested during PEI via the EFI_AUTHENTICATED_VARIABLE_HOB, but |
| these updates won't be written to non-volatile storage until later in DXE. |
| The EFI_AUTHENTICATED_VARIABLE_HOB is a HOB with the GUID |
| gEfiAuthenticatedVariableGuid. This HOB contains a VARIABLE_STORE_HEADER followed |
| by one or more UEFI variables, which are stored as DWORD aligned tuples of |
| (VARIABLE_HEADER + CHAR16 VariableName + VariableData). |
| See MdeModulePkg/Include/Guid/VariableFormat.h for these data structure |
| definitions and MdeModulePkg/Universal/Variable/RuntimeDxe/VariableParsing.c for |
| an example of how to parse these data structures. |
| @retval EFI_NOT_FOUND The variable trying to be updated or deleted was not found. |
| |
| **/ |
| typedef |
| EFI_STATUS |
| (EFIAPI *EDKII_PEI_SET_VARIABLE)( |
| IN CONST EDKII_PEI_VARIABLE_PPI *This, |
| IN CHAR16 *VariableName, |
| IN EFI_GUID *VendorGuid, |
| IN UINT32 Attributes, |
| IN UINTN DataSize, |
| IN VOID *Data |
| ); |
| |
| /** |
| Returns information about the UEFI variables. |
| |
| @param[in] This A pointer to this instance of the EDKII_PEI_VARIABLE_PPI. |
| @param[in] Attributes Attributes bitmask to specify the type of variables on |
| which to return information. |
| @param[out] MaximumVariableStorageSize On output the maximum size of the storage space |
| available for the EFI variables associated with the |
| attributes specified. |
| @param[out] RemainingVariableStorageSize Returns the remaining size of the storage space |
| available for the EFI variables associated with the |
| attributes specified. |
| @param[out] MaximumVariableSize Returns the maximum size of the individual EFI |
| variables associated with the attributes specified. |
| |
| @retval EFI_SUCCESS Valid answer returned. |
| @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits was supplied |
| @retval EFI_UNSUPPORTED The attribute is not supported on this platform, and the |
| MaximumVariableStorageSize, |
| RemainingVariableStorageSize, MaximumVariableSize |
| are undefined. |
| |
| **/ |
| typedef |
| EFI_STATUS |
| (EFIAPI *EDKII_PEI_QUERY_VARIABLE_INFO)( |
| IN CONST EDKII_PEI_VARIABLE_PPI *This, |
| IN UINT32 Attributes, |
| OUT UINT64 *MaximumVariableStorageSize, |
| OUT UINT64 *RemainingVariableStorageSize, |
| OUT UINT64 *MaximumVariableSize |
| ); |
| |
| /// |
| /// PEI Variable PPI is intended for use as a means |
| /// to store data in the PEI environment. |
| /// |
| struct _EDKII_PEI_VARIABLE_PPI { |
| EDKII_PEI_GET_VARIABLE GetVariable; |
| EDKII_PEI_GET_NEXT_VARIABLE_NAME GetNextVariableName; |
| EDKII_PEI_SET_VARIABLE SetVariable; |
| EDKII_PEI_QUERY_VARIABLE_INFO QueryVariableInfo; |
| }; |
| |
| extern EFI_GUID gEdkiiPeiVariablePpiGuid; |
| |
| #endif |