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1 | // /** @file\r |
2 | // PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service.\r | |
3 | //\r | |
4 | // This version PCD PEIM depends on the external PCD database binary file, not built in PCD data base.\r | |
5 | // There are two PCD PPIs as follows:\r | |
6 | // 1) PCD_PPI\r | |
7 | // It is EDKII implementation which support Dynamic/DynamicEx Pcds.\r | |
8 | // 2) EFI_PEI_PCD_PPI\r | |
9 | // It is defined by PI specification 1.2, Vol 3 which only support dynamicEx\r | |
10 | // type Pcd.\r | |
11 | // For dynamicEx type PCD, it is compatible between PCD_PPI and EFI_PEI_PCD_PPI.\r | |
12 | // PCD PEIM driver will produce above two PPIs at same time.\r | |
13 | // \r | |
14 | // PCD database is generated as the separate binary image at build time. The binary image\r | |
15 | // will be intergrated into Firmware volume together with PCD driver.\r | |
16 | // \r | |
17 | // ////////////////////////////////////////////////////////////////////////////////\r | |
18 | // // //\r | |
19 | // // Introduction of PCD database //\r | |
20 | // // //\r | |
21 | // ////////////////////////////////////////////////////////////////////////////////\r | |
22 | // \r | |
23 | // 1, Introduction\r | |
24 | // PCD database hold all dynamic type PCD information. The structure of PEI PCD\r | |
25 | // database is generated by build tools according to dynamic PCD usage for\r | |
26 | // specified platform.\r | |
27 | // \r | |
28 | // 2, Dynamic Type PCD\r | |
29 | // Dynamic type PCD is used for the configuration/setting which value is determined\r | |
30 | // dynamic. In contrast, the value of static type PCD (FeatureFlag, FixedPcd,\r | |
31 | // PatchablePcd) is fixed in final generated FD image in build time.\r | |
32 | // \r | |
33 | // 2.1 The "dynamic" determination means one of below cases:\r | |
34 | // a) The PCD setting value is produced by someone driver and consumed by\r | |
35 | // other driver in execution time.\r | |
36 | // b) The PCD setting value is set/get by user from FrontPage.\r | |
37 | // c) The PCD setting value is produced by platform OEM vendor in specified area.\r | |
38 | // \r | |
39 | // 2.2 According to module distribution way, dynamic PCD could be classfied as:\r | |
40 | // a) Dynamic:\r | |
41 | // If module is released in source code and will be built with platform\r | |
42 | // DSC, the dynamic PCD used by this module can be accessed as:\r | |
43 | // PcdGetxx(PcdSampleDynamicPcd);\r | |
44 | // In building platform, build tools will translate PcdSampleDynamicPcd to\r | |
45 | // pair of {Token Space Guid: Token Number} for this PCD.\r | |
46 | // b) DynamicEx:\r | |
47 | // If module is release as binary and will not pariticpate platform building,\r | |
48 | // the dynamic PCD used by this module need be accessed as:\r | |
49 | // PcdGetxxEx(gEfiMyTokenspaceGuid, PcdSampleDynamicPcd)\r | |
50 | // Developer need explicity gives {Token Space Guid:Token Number} as parameter\r | |
51 | // in writting source code.\r | |
52 | // \r | |
53 | // 2.3 According to PCD value's storage method, dynamic PCD could be classfied as:\r | |
54 | // a) Default Storage:\r | |
55 | // - The PCD value is stored in PCD database maintained by PCD driver in boot\r | |
56 | // time memory.\r | |
57 | // - This type is used for communication between PEIM/DXE driver, DXE/DXE\r | |
58 | // driver. But all set/get value will be losted after boot-time memory\r | |
59 | // is turn off.\r | |
60 | // - [PcdsDynamicDefault] is used as section name for this type PCD in\r | |
61 | // platform DSC file. [PcdsDynamicExDefault] is used for dynamicEx type PCD.\r | |
62 | // \r | |
63 | // b) Variable Storage:\r | |
64 | // - The PCD value is stored in variable area.\r | |
65 | // - As default storage type, this type PCD could be used for PEI/DXE driver\r | |
66 | // communication. But beside it, this type PCD could also be used to store\r | |
67 | // the value associate with a HII setting via variable interface.\r | |
68 | // - In PEI phase, the PCD value could only be got but can not be set due\r | |
69 | // to variable area is readonly.\r | |
70 | // - [PcdsDynamicHii] is used as section name for this type PCD in platform\r | |
71 | // DSC file. [PcdsDynamicExHii] is for dynamicEx type PCD.\r | |
72 | // \r | |
73 | // c) OEM specificed storage area:\r | |
74 | // - The PCD value is stored in OEM specified area which base address is\r | |
75 | // specified by a FixedAtBuild PCD setting - PcdVpdBaseAddress.\r | |
76 | // - The area is read only for PEI and DXE phase.\r | |
77 | // - [PcdsDynamicVpd] is used as section name for this type PCD in platform\r | |
78 | // DSC file. [PcdsDynamicExVpd] is for dynamicex type PCD.\r | |
79 | // \r | |
80 | // 2.4 When and how to use dynamic PCD\r | |
81 | // Module developer do not care the used PCD is dynamic or static when writting\r | |
82 | // source code/INF. Dynamic PCD and dynamic type is pointed by platform integrator\r | |
83 | // in platform DSC file. Please ref section 2.3 to get matching between dynamic\r | |
84 | // PCD type and section name in DSC file.\r | |
85 | // \r | |
86 | // 3, PCD database:\r | |
87 | // Although dynamic PCD could be in different storage type as above description,\r | |
88 | // but the basic information and default value for all dynamic PCD is hold\r | |
89 | // by PCD database maintained by PEI/DXE driver.\r | |
90 | // \r | |
91 | // As the whole EFI BIOS boot path is divided into PEI/DXE phase, the PCD database\r | |
92 | // also is divided into Pei/Dxe database maintaied by PcdPeim/PcdDxe driver separatly.\r | |
93 | // To make PcdPeim's driver image smaller, PEI PCD database only hold all dynamic\r | |
94 | // PCD information used in PEI phase or use in both PEI/DXE phase. And DXE PCD\r | |
95 | // database contains all PCDs used in PEI/DXE phase in memory.\r | |
96 | // \r | |
97 | // Build tool will generate PCD database into the separate binary file for\r | |
98 | // PEI/DXE PCD driver according to dynamic PCD section in platform DSC file.\r | |
99 | // \r | |
100 | // 3.1 PcdPeim and PcdDxe\r | |
101 | // PEI PCD database is maintained by PcdPeim driver run from flash. PcdPeim driver\r | |
102 | // build guid hob in temporary memory and copy the binary data base from flash\r | |
103 | // to temporary memory for PEI PCD database.\r | |
104 | // DXE PCD database is maintained by PcdDxe driver.At entry point of PcdDxe driver,\r | |
105 | // a new PCD database is allocated in boot-time memory which including all\r | |
106 | // PEI PCD and DXE PCD entry.\r | |
107 | // \r | |
108 | // Pcd driver should run as early as possible before any other driver access\r | |
109 | // dynamic PCD's value. PEI/DXE "Apriori File" mechanism make it possible by\r | |
110 | // making PcdPeim/PcdDxe as first dispatching driver in PEI/DXE phase.\r | |
111 | // \r | |
112 | // 3.2 Token space Guid/Token number, Platform token, Local token number\r | |
113 | // Dynamic PCD\r | |
114 | // +-----------+ +---------+\r | |
115 | // |TokenSpace | |Platform |\r | |
116 | // | Guid | build tool | Token |\r | |
117 | // | + +-------------->| Number |\r | |
118 | // | Token | +---------+`._\r | |
119 | // | Number | `.\r | |
120 | // +-----------+ `. +------+\r | |
121 | // `-|Local |\r | |
122 | // |Token |\r | |
123 | // DynamicEx PCD ,-|Number|\r | |
124 | // +-----------+ ,-' +------+\r | |
125 | // |TokenSpace | ,-'\r | |
126 | // | Guid | _,-'\r | |
127 | // | + +.'\r | |
128 | // | Token |\r | |
129 | // | Number |\r | |
130 | // +-----------+\r | |
131 | // \r | |
132 | // \r | |
133 | // 3.2.1 Pair of Token space guid + Token number\r | |
134 | // Any type PCD is identified by pair of "TokenSpaceGuid + TokeNumber". But it\r | |
135 | // is not easy maintained by PCD driver, and hashed token number will make\r | |
136 | // searching slowly.\r | |
137 | // \r | |
138 | // 3.2.2 Platform Token Number\r | |
139 | // "Platform token number" concept is introduced for mapping to a pair of\r | |
140 | // "TokenSpaceGuid + TokenNumber". The platform token number is generated by\r | |
141 | // build tool in autogen.h and all of them are continual in a platform scope\r | |
142 | // started from 1.(0 meaning invalid internal token number)\r | |
143 | // With auto-generated "platform token number", PcdGet(PcdSampleDynamicPcd)\r | |
144 | // in source code is translated to LibPcdGet(_PCD_TOKEN_PcdSampleDynamicPcd)\r | |
145 | // in autogen.h.\r | |
146 | // Notes: The mapping between pair of "tokenspace guid + token number" and\r | |
147 | // "internal token number" need build tool establish, so "platform token number"\r | |
148 | // mechanism is not suitable for binary module which use DynamicEx type PCD.\r | |
149 | // To access a dynamicEx type PCD, pair of "token space guid/token number" all need\r | |
150 | // to be specificed for PcdSet/PcdGet accessing macro.\r | |
151 | // \r | |
152 | // Platform Token Number is started from 1, and inceased continuous. From whole\r | |
153 | // platform scope, there are two zones: PEI Zone and DXE Zone\r | |
154 | // | Platform Token Number\r | |
155 | // ----------|----------------------------------------------------------------\r | |
156 | // PEI Zone: | 1 ~ PEI_LOCAL_TOKEN_NUMBER\r | |
157 | // DXE Zone: | (PEI_LOCAL_TOKEN_NUMBER + 1) ~ (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER)\r | |
158 | // \r | |
159 | // 3.2.3 Local Token Number\r | |
160 | // To fast searching a PCD entry in PCD database, PCD driver translate\r | |
161 | // platform token number to local token number via a mapping table.\r | |
162 | // For binary DynamicEx type PCD, there is a another mapping table to translate\r | |
163 | // "token space guid + token number" to local token number directly.\r | |
164 | // Local token number is identifier for all internal interface in PCD PEI/DXE\r | |
165 | // driver.\r | |
166 | // \r | |
167 | // A local token number is a 32-bit value in following meaning:\r | |
168 | // 32 ------------- 28 ---------- 24 -------- 0\r | |
169 | // | PCD type mask | Datum Type | Offset |\r | |
170 | // +-----------------------------------------+\r | |
171 | // where:\r | |
172 | // PCd type mask: indicate Pcd type from following macro:\r | |
173 | // PCD_TYPE_DATA\r | |
174 | // PCD_TYPE_HII\r | |
175 | // PCD_TYPE_VPD\r | |
176 | // PCD_TYPE_SKU_ENABLED\r | |
177 | // PCD_TYPE_STRING\r | |
178 | // Datum Type : indicate PCD vaue type from following macro:\r | |
179 | // PCD_DATUM_TYPE_POINTER\r | |
180 | // PCD_DATUM_TYPE_UINT8\r | |
181 | // PCD_DATUM_TYPE_UINT16\r | |
182 | // PCD_DATUM_TYPE_UINT32\r | |
183 | // PCD_DATUM_TYPE_UINT64\r | |
184 | // Offset : indicate the related offset of PCD value in PCD database array.\r | |
185 | // Based on local token number, PCD driver could fast determine PCD type, value\r | |
186 | // type and get PCD entry from PCD database.\r | |
187 | // \r | |
188 | // 3.3 PCD Database binary file\r | |
189 | // PCD Database binary file will be created at build time as the standalone binary image.\r | |
190 | // To understand the binary image layout, PCD Database C structure is still generated\r | |
191 | // as comments by build tools in PCD driver's autogen.h/\r | |
192 | // autogen.c file. In generated C structure, following information is stored:\r | |
193 | // - ExMapTable: This table is used translate a binary dynamicex type PCD's\r | |
194 | // "tokenguid + token" to local token number.\r | |
195 | // - LocalTokenNumberTable:\r | |
196 | // This table stores all local token number in array, use "Internal\r | |
197 | // token number" as array index to get PCD entry's offset fastly.\r | |
198 | // - SizeTable: This table stores the size information for all PCD entry.\r | |
199 | // - GuidTable: This table stores guid value for DynamicEx's token space,\r | |
200 | // HII type PCD's variable GUID.\r | |
201 | // - SkuIdTable: TBD\r | |
202 | // - SystemSkuId: TBD\r | |
203 | // - PCD value structure:\r | |
204 | // Every PCD has a value record in PCD database. For different\r | |
205 | // datum type PCD has different record structure which will be\r | |
206 | // introduced in 3.3.1\r | |
207 | // \r | |
208 | // In a PCD database structure, there are two major area: Init and UnInit.\r | |
209 | // Init area is use stored above PCD internal structure such as ExMapTable,\r | |
210 | // LocalTokenNumberTable etc and the (default) value of PCD which has default\r | |
211 | // value specified in platform DSC file.\r | |
212 | // Unint area is used stored the value of PCD which has no default value in\r | |
213 | // platform DSC file, the value of NULL, 0 specified in platform DSC file can\r | |
214 | // be seemed as "no default value".\r | |
215 | // \r | |
216 | // 3.3.1 Simple Sample PCD Database C Structure\r | |
217 | // A general sample of PCD database structue is as follows:\r | |
218 | // typedef struct _PCD_DATABASE {\r | |
219 | // typedef struct _PCD_DATABASE_INIT {\r | |
220 | // //===== Following is PCD database internal maintain structures\r | |
221 | // DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE];\r | |
222 | // UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE];\r | |
223 | // GUID GuidTable[PEI_GUID_TABLE_SIZE];\r | |
224 | // SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE];\r | |
225 | // UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE];\r | |
226 | // SKU_ID SystemSkuId;\r | |
227 | // \r | |
228 | // //===== Following is value structure for PCD with default value\r | |
229 | // ....\r | |
230 | // ....\r | |
231 | // ....\r | |
232 | // } Init;\r | |
233 | // typedef struct _PCD_DATABSE_UNINIT {\r | |
234 | // //==== Following is value structure for PCD without default value\r | |
235 | // ....\r | |
236 | // ....\r | |
237 | // } UnInit;\r | |
238 | // }\r | |
239 | // \r | |
240 | // 3.3.2 PCD value structure in PCD database C structure\r | |
241 | // The value's structure is generated by build tool in PCD database C structure.\r | |
242 | // The PCDs in different datum type has different value structure.\r | |
243 | // \r | |
244 | // 3.3.2.1 UINT8/UINT16/UINT32/UINT64 datum type PCD\r | |
245 | // The C structure for these datum type PCD is just a UINT8/UINT16/UINT32/UINT64\r | |
246 | // data member in PCD database, For example:\r | |
247 | // UINT16 PcdHardwareErrorRecordLevel_d3705011_bc19_4af7_be16_f68030378c15_VariableDefault_0;\r | |
248 | // Above structure is generated by build tool, the member name is "PcdCName_Guidvalue"\r | |
249 | // Member type is UINT16 according to PcdHardwareErrorRecordLevel declaration\r | |
250 | // in DEC file.\r | |
251 | // \r | |
252 | // 3.3.2.2 VOID* datum type PCD\r | |
253 | // The value of VOID* datum type PCD is a UINT8/UINT16 array in PCD database.\r | |
254 | // \r | |
255 | // 3.3.2.2.1 VOID* - string type\r | |
256 | // If the default value for VOID* datum type PCD like L"xxx", the PCD is\r | |
257 | // used for unicode string, and C structure of this datum type PCD is\r | |
258 | // UINT16 string array in PCD database, for example:\r | |
259 | // UINT16 StringTable[29];\r | |
260 | // The number of 29 in above sample is max size of a unicode string.\r | |
261 | // \r | |
262 | // If the default value for VOID* datum type PCD like "xxx", the PCD is\r | |
263 | // used for ascii string, and C structure of this datum type PCD is\r | |
264 | // UINT8 string array in PCD database, for example:\r | |
265 | // UINT8 StringTable[20];\r | |
266 | // The number of 20 in above sample is max size of a ascii string.\r | |
267 | // \r | |
268 | // 3.3.2.2.2 VOID* - byte array\r | |
269 | // If the default value of VOID* datum type PCD like {'0x29', '0x01', '0xf2'}\r | |
270 | // the PCD is used for byte array. The generated structrue is same as\r | |
271 | // above ascii string table,\r | |
272 | // UINT8 StringTable[13];\r | |
273 | // The number of 13 in above sample is max size of byte array.\r | |
274 | // \r | |
275 | // 3.3.3 Some utility structures in PCD Database\r | |
276 | // 3.3.3.1 GuidTable\r | |
277 | // GuidTable array is used to store all related GUID value in PCD database:\r | |
278 | // - Variable GUID for HII type PCD\r | |
279 | // - Token space GUID for dynamicex type PCD\r | |
280 | //\r | |
281 | // Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>\r | |
282 | //\r | |
283 | // This program and the accompanying materials\r | |
284 | // are licensed and made available under the terms and conditions of the BSD License\r | |
285 | // which accompanies this distribution. The full text of the license may be found at\r | |
286 | // http://opensource.org/licenses/bsd-license.php\r | |
287 | // THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
288 | // WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
289 | //\r | |
290 | // **/\r | |
291 | \r | |
292 | \r | |
293 | #string STR_MODULE_ABSTRACT #language en-US "PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service."\r | |
294 | \r | |
295 | #string STR_MODULE_DESCRIPTION #language en-US "PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service."\r | |
296 | \r |