/** @file | |
This file declares the Read-only Variable Service PPI, which is required by the framework spec. | |
These services provide a lightweight, read-only variant of the full EFI variable services. The | |
reason that these services are read-only is to reduce the complexity of flash management. Also, | |
some implementation of the PEI may use the same physical flash part for variable and PEIM | |
storage. As such, a write command to certain technologies would alter the contents of the entire part, | |
making the PEIM execution in the original position not follow the required flow. | |
Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR> | |
This program and the accompanying materials are licensed and made available under | |
the terms and conditions of the BSD License that accompanies this distribution. | |
The full text of the license may be found at | |
http://opensource.org/licenses/bsd-license.php. | |
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
@par Revision Reference: | |
This PPI is defined in PEI CIS | |
Version 0.91. | |
**/ | |
#ifndef __PEI_READ_ONLY_VARIABLE_PPI_H__ | |
#define __PEI_READ_ONLY_VARIABLE_PPI_H__ | |
#define EFI_PEI_READ_ONLY_VARIABLE_ACCESS_PPI_GUID \ | |
{ \ | |
0x3cdc90c6, 0x13fb, 0x4a75, {0x9e, 0x79, 0x59, 0xe9, 0xdd, 0x78, 0xb9, 0xfa } \ | |
} | |
typedef struct _EFI_PEI_READ_ONLY_VARIABLE_PPI EFI_PEI_READ_ONLY_VARIABLE_PPI; | |
/// | |
/// Variable attributes. | |
///@{ | |
#define EFI_VARIABLE_NON_VOLATILE 0x00000001 | |
#define EFI_VARIABLE_BOOTSERVICE_ACCESS 0x00000002 | |
#define EFI_VARIABLE_RUNTIME_ACCESS 0x00000004 | |
/// | |
/// Inconsistent with specification here: | |
/// In Framework Spec, PeiCis0.91, neither the macro or its value is defined. | |
/// Keeping this inconsistancy for backward compatibility. | |
/// | |
#define EFI_VARIABLE_READ_ONLY 0x00000008 | |
///@} | |
/** | |
Get Variable value by Name and GUID pair. | |
@param[in] PeiServices An indirect pointer to the PEI Services Table published | |
by the PEI Foundation. | |
@param[in] VariableName A NULL-terminated Unicode string that is the name of the vendor's variable. | |
@param[in] VendorGuid A unique identifier for the vendor. | |
@param[out] Attributes This OPTIONAL parameter may be either NULL or | |
a pointer to the location in which to return | |
the attributes bitmask for the variable. | |
@param[in,out] DataSize On input, the size in bytes of the return Data buffer. | |
On output, the size of data returned in Data. | |
@param[out] Data The buffer to return the contents of the variable. | |
@retval EFI_SUCCESS The function completed successfully. | |
@retval EFI_NOT_FOUND The variable was not found. | |
@retval EFI_BUFFER_TOO_SMALL The BufferSize is too small for the result. | |
@retval EFI_INVALID_PARAMETER One of the parameters has an invalid value. | |
@retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *EFI_PEI_GET_VARIABLE)( | |
IN EFI_PEI_SERVICES **PeiServices, | |
IN CHAR16 *VariableName, | |
IN EFI_GUID *VendorGuid, | |
OUT UINT32 *Attributes OPTIONAL, | |
IN OUT UINTN *DataSize, | |
OUT VOID *Data | |
); | |
/** | |
This function can be called multiple times to retrieve the VariableName | |
and VendorGuid of all variables currently available in the system. On each call | |
to GetNextVariableName(), the previous results are passed into the interface, | |
and on output the interface returns the next variable name data. When the | |
entire variable list has been returned, the error EFI_NOT_FOUND is returned. | |
@param[in] PeiServices An indirect pointer to the PEI Services Table | |
published by the PEI Foundation. | |
@param[in] VariableNameSize The size of the VariableName buffer. | |
@param[in] VariableName On input, supplies the last VariableName that was | |
returned by GetNextVariableName(). On output, | |
returns the Null-terminated Unicode string of the | |
current variable. | |
@param[in] VendorGuid On input, supplies the last VendorGuid that was | |
returned by GetNextVariableName(). On output, | |
returns the VendorGuid of the current variable. | |
@retval EFI_SUCCESS The function completed successfully. | |
@retval EFI_NOT_FOUND The next variable was not found. | |
@retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the result. | |
@retval EFI_INVALID_PARAMETER One of the parameters has an invalid value. | |
@retval EFI_DEVICE_ERROR The variable name could not be retrieved due to | |
a hardware error. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *EFI_PEI_GET_NEXT_VARIABLE_NAME)( | |
IN EFI_PEI_SERVICES **PeiServices, | |
IN OUT UINTN *VariableNameSize, | |
IN OUT CHAR16 *VariableName, | |
IN OUT EFI_GUID *VendorGuid | |
); | |
/// | |
/// This PPI provides a lightweight, read-only variant of the full EFI | |
/// variable services. | |
/// | |
struct _EFI_PEI_READ_ONLY_VARIABLE_PPI { | |
/// | |
/// Inconsistent with specification here: | |
/// In Framework Spec, PeiCis0.91, the field is named as GetVariable and GetNextVariableName. | |
/// Keeping this inconsistancy for backward compatibility. | |
/// | |
EFI_PEI_GET_VARIABLE PeiGetVariable; ///< A service to ascertain a given variable name. | |
EFI_PEI_GET_NEXT_VARIABLE_NAME PeiGetNextVariableName; ///< A service to ascertain a variable based upon a given, known variable | |
}; | |
extern EFI_GUID gEfiPeiReadOnlyVariablePpiGuid; | |
#endif /* __PEI_READ_ONLY_VARIABLE_PPI_H__ */ | |