Add more comments for IntelFramework's header files.
[mirror_edk2.git] / IntelFrameworkPkg / Include / Ppi / ReadOnlyVariable.h
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3e5a3960 1/** @file\r
2 This file declares Read-only Variable Service PPI\r
4a71b21a 3 These services provide a lightweight, read-only variant of the full EFI variable services. The\r
4 reason that these services are read-only is to reduce the complexity of flash management. Also,\r
5 some implementation of the PEI may use the same physical flash part for variable and PEIM\r
6 storage; as such, a write command to certain technologies would alter the contents of the entire part,\r
7 thus making the in situ PEIM execution not follow the required flow.\r
3e5a3960 8\r
b80fbe85 9 Copyright (c) 2006, Intel Corporation\r
10 All rights reserved. This program and the accompanying materials\r
11 are licensed and made available under the terms and conditions of the BSD License\r
12 which accompanies this distribution. The full text of the license may be found at\r
13 http://opensource.org/licenses/bsd-license.php\r
3e5a3960 14\r
b80fbe85 15 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
16 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
3e5a3960 17\r
18 Module Name: ReadOnlyVariable.h\r
19\r
20 @par Revision Reference:\r
21 This PPI is defined in PEI CIS\r
22 Version 0.91.\r
23\r
24**/\r
25\r
26#ifndef __PEI_READ_ONLY_VARIABLE_PPI_H__\r
27#define __PEI_READ_ONLY_VARIABLE_PPI_H__\r
28\r
b80fbe85 29#include <PiPei.h>\r
30\r
3e5a3960 31#define EFI_PEI_READ_ONLY_VARIABLE_ACCESS_PPI_GUID \\r
32 { \\r
33 0x3cdc90c6, 0x13fb, 0x4a75, {0x9e, 0x79, 0x59, 0xe9, 0xdd, 0x78, 0xb9, 0xfa } \\r
34 }\r
35\r
36typedef struct _EFI_PEI_READ_ONLY_VARIABLE_PPI EFI_PEI_READ_ONLY_VARIABLE_PPI;\r
37\r
38//\r
39// Variable attributes\r
40//\r
41#define EFI_VARIABLE_NON_VOLATILE 0x00000001\r
42#define EFI_VARIABLE_BOOTSERVICE_ACCESS 0x00000002\r
43#define EFI_VARIABLE_RUNTIME_ACCESS 0x00000004\r
44#define EFI_VARIABLE_READ_ONLY 0x00000008\r
45\r
46/**\r
47 Get Variable value by Name and GUID pair\r
48\r
49 @param PeiServices An indirect pointer to the PEI Services Table published by the PEI Foundation.\r
50 @param VariableName A NULL-terminated Unicode string that is the name of the vendor's variable.\r
51 @param VendorGuid A unique identifier for the vendor.\r
52 @param Attributes If not NULL, a pointer to the memory location to return\r
53 the attributes bitmask for the variable.\r
54 @param DataSize On input, the size in bytes of the return Data buffer.\r
55 On output, the size of data returned in Data.\r
56 @param Data The buffer to return the contents of the variable.\r
57\r
58 @retval EFI_SUCCESS The function completed successfully.\r
59 @retval EFI_NOT_FOUND The variable was not found.\r
60 @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small for the result.\r
61 @retval EFI_INVALID_PARAMETER One of the parameters has an invalid value.\r
62 @retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error.\r
63\r
64**/\r
65typedef\r
66EFI_STATUS\r
67(EFIAPI *EFI_PEI_GET_VARIABLE) (\r
68 IN EFI_PEI_SERVICES **PeiServices,\r
69 IN CHAR16 *VariableName,\r
70 IN EFI_GUID *VendorGuid,\r
71 OUT UINT32 *Attributes OPTIONAL,\r
72 IN OUT UINTN *DataSize,\r
73 OUT VOID *Data\r
74 );\r
75\r
76/**\r
b80fbe85 77 This function can be called multiple times to retrieve the VariableName\r
78 and VendorGuid of all variables currently available in the system. On each call\r
79 to GetNextVariableName() the previous results are passed into the interface,\r
80 and on output the interface returns the next variable name data. When the\r
3e5a3960 81 entire variable list has been returned, the error EFI_NOT_FOUND is returned.\r
82\r
83 @param PeiServices An indirect pointer to the PEI Services Table published by the PEI Foundation.\r
84 @param VariableNameSize The size of the VariableName buffer.\r
85 @param VariableName On input, supplies the last VariableName that was\r
86 returned by GetNextVariableName(). On output, returns the Null-terminated\r
87 Unicode string of the current variable.\r
88 @param VendorGuid On input, supplies the last VendorGuid that was\r
89 returned by GetNextVariableName(). On output, returns the VendorGuid\r
90 of the current variable.\r
91\r
92 @retval EFI_SUCCESS The function completed successfully.\r
93 @retval EFI_NOT_FOUND The next variable was not found.\r
94 @retval EFI_BUFFER_TOO_SMALL The VariableNameSize is too small for the result.\r
95 @retval EFI_INVALID_PARAMETER One of the parameters has an invalid value.\r
96 @retval EFI_DEVICE_ERROR The variable name could not be retrieved due to a hardware error.\r
97\r
98**/\r
99typedef\r
100EFI_STATUS\r
101(EFIAPI *EFI_PEI_GET_NEXT_VARIABLE_NAME) (\r
102 IN EFI_PEI_SERVICES **PeiServices,\r
103 IN OUT UINTN *VariableNameSize,\r
104 IN OUT CHAR16 *VariableName,\r
105 IN OUT EFI_GUID *VendorGuid\r
106 );\r
107\r
108/**\r
109 @par Ppi Description:\r
b80fbe85 110 This PPI provides a lightweight, read-only variant of the full EFI\r
111 variable services.\r
3e5a3960 112\r
113 @param GetVariable\r
114 A service to ascertain a given variable name.\r
115\r
116 @param GetNextVariableName\r
117 A service to ascertain a variable based upon a given, known variable\r
118\r
119**/\r
120struct _EFI_PEI_READ_ONLY_VARIABLE_PPI {\r
121 EFI_PEI_GET_VARIABLE PeiGetVariable;\r
122 EFI_PEI_GET_NEXT_VARIABLE_NAME PeiGetNextVariableName;\r
123};\r
124\r
125extern EFI_GUID gEfiPeiReadOnlyVariablePpiGuid;\r
126\r
127#endif\r