# PEI phase, DXE phase and produce the implementation of PCD protocol.\r
# PCD database structure is generated at autogen.h/autogen.c in build time.\r
#\r
+# ////////////////////////////////////////////////////////////////////////////////\r
+# // //\r
+# // Introduction of PCD database //\r
+# // //\r
+# ////////////////////////////////////////////////////////////////////////////////\r
+#\r
+# 1, Introduction\r
+# PCD database hold all dynamic type PCD information. The structure of PEI PCD \r
+# database is generated by build tools according to dynamic PCD usage for \r
+# specified platform.\r
+# \r
+# 2, Dynamic Type PCD\r
+# Dynamic type PCD is used for the configuration/setting which value is determined\r
+# dynamic. In contrast, the value of static type PCD (FeatureFlag, FixedPcd, \r
+# PatchablePcd) is fixed in final generated FD image in build time. \r
+# \r
+# 2.1 The "dynamic" determination means one of below cases:\r
+# a) The PCD setting value is produced by someone driver and consumed by \r
+# other driver in execution time.\r
+# b) The PCD setting value is set/get by user from FrontPage.\r
+# c) The PCD setting value is produced by platform OEM vendor in specified area.\r
+# \r
+# 2.2 According to module distribution way, dynamic PCD could be classfied as:\r
+# a) Dynamic:\r
+# If module is released in source code and will be built with platform \r
+# DSC, the dynamic PCD used by this module can be accessed as:\r
+# PcdGetxx(PcdSampleDynamicPcd); \r
+# In building platform, build tools will translate PcdSampleDynamicPcd to\r
+# pair of {Token Space Guid: Token Number} for this PCD. \r
+# b) DynamicEx:\r
+# If module is release as binary and will not pariticpate platform building,\r
+# the dynamic PCD used by this module need be accessed as:\r
+# PcdGetxxEx(gEfiMyTokenspaceGuid, PcdSampleDynamicPcd)\r
+# Developer need explicity gives {Token Space Guid:Token Number} as parameter\r
+# in writting source code.\r
+# \r
+# 2.3 According to PCD value's storage method, dynamic PCD could be classfied as:\r
+# a) Default Storage: \r
+# - The PCD value is stored in PCD database maintained by PCD driver in boot \r
+# time memory.\r
+# - This type is used for communication between PEIM/DXE driver, DXE/DXE \r
+# driver. But all set/get value will be losted after boot-time memory \r
+# is turn off.\r
+# - [PcdsDynamicDefault] is used as section name for this type PCD in \r
+# platform DSC file. [PcdsDynamicExDefault] is used for dynamicEx type PCD.\r
+# \r
+# b) Variable Storage: \r
+# - The PCD value is stored in variable area. \r
+# - As default storage type, this type PCD could be used for PEI/DXE driver\r
+# communication. But beside it, this type PCD could alsp be used to store \r
+# the value associate with a HII setting via variable interface.\r
+# - In PEI phase, the PCD value could only be got but can not be set due \r
+# to variable area is readonly.\r
+# - [PcdsDynamicHii] is used as section name for this type PCD in platform \r
+# DSC file. [PcdsDynamicExHii] is for dynamicEx type PCD.\r
+# \r
+# c) OEM specificed storage area:\r
+# - The PCD value is stored in OEM specified area which base address is \r
+# specified by a FixedAtBuild PCD setting - PcdVpdBaseAddress.\r
+# - The area is read only for PEI and DXE phase.\r
+# - [PcdsDynamicVpd] is used as section name for this type PCD in platform \r
+# DSC file. [PcdsDynamicExVpd] is for dynamicex type PCD.\r
+# \r
+# 2.4 When and how to use dynamic PCD\r
+# Module developer do not care the used PCD is dynamic or static when writting\r
+# source code/INF. Dynamic PCD and dynamic type is pointed by platform integrator \r
+# in platform DSC file. Please ref section 2.3 to get matching between dynamic\r
+# PCD type and section name in DSC file.\r
+# \r
+# 3, PCD database:\r
+# Although dynamic PCD could be in different storage type as above description, \r
+# but the basic information and default value for all dynamic PCD is hold\r
+# by PCD database maintained by PEI/DXE driver.\r
+# \r
+# As the whole EFI BIOS boot path is divided into PEI/DXE phase, the PCD database\r
+# also is divided into Pei/Dxe database maintaied by PcdPeim/PcdDxe driver separatly.\r
+# To make PcdPeim's driver image smaller, PEI PCD database only hold all dynamic\r
+# PCD information used in PEI phase or use in both PEI/DXE phase. And DXE PCD\r
+# database contains all PCDs used in PEI/DXE phase in memory.\r
+# \r
+# Build tool will generate PCD database into some C structure and variable for \r
+# PEI/DXE PCD driver according to dynamic PCD section in platform DSC file. \r
+# \r
+# 3.1 PcdPeim and PcdDxe\r
+# PEI PCD database is maintained by PcdPeim driver run from flash. PcdPeim driver\r
+# build guid hob in temporary memory and copy auto-generated C structure \r
+# to temporary memory for PEI PCD database. \r
+# DXE PCD database is maintained by PcdDxe driver.At entry point of PcdDxe driver,\r
+# a new PCD database is allocated in boot-time memory which including all\r
+# PEI PCD and DXE PCD entry.\r
+# \r
+# Pcd driver should run as early as possible before any other driver access\r
+# dynamic PCD's value. PEI/DXE "Apriori File" mechanism make it possible by\r
+# making PcdPeim/PcdDxe as first dispatching driver in PEI/DXE phase.\r
+# \r
+# 3.2 Token space Guid/Token number, Platform token, Local token number\r
+# Dynamic PCD\r
+# +-----------+ +---------+\r
+# |TokenSpace | |Platform |\r
+# | Guid | build tool | Token |\r
+# | + +-------------->| Number |\r
+# | Token | +---------+`._\r
+# | Number | `.\r
+# +-----------+ `. +------+\r
+# `-|Local |\r
+# |Token |\r
+# DynamicEx PCD ,-|Number|\r
+# +-----------+ ,-' +------+\r
+# |TokenSpace | ,-'\r
+# | Guid | _,-'\r
+# | + +.'\r
+# | Token |\r
+# | Number |\r
+# +-----------+\r
+# \r
+# \r
+# 3.2.1 Pair of Token space guid + Token number\r
+# Any type PCD is identified by pair of "TokenSpaceGuid + TokeNumber". But it\r
+# is not easy maintained by PCD driver, and hashed token number will make \r
+# searching slowly. \r
+#\r
+# 3.2.2 Platform Token Number\r
+# "Platform token number" concept is introduced for mapping to a pair of \r
+# "TokenSpaceGuid + TokenNumber". The platform token number is generated by \r
+# build tool in autogen.h and all of them are continual in a platform scope \r
+# started from 1.(0 meaning invalid internal token number)\r
+# With auto-generated "platform token number", PcdGet(PcdSampleDynamicPcd)\r
+# in source code is translated to LibPcdGet(_PCD_TOKEN_PcdSampleDynamicPcd) \r
+# in autogen.h.\r
+# Notes: The mapping between pair of "tokenspace guid + token number" and\r
+# "internal token number" need build tool establish, so "platform token number"\r
+# mechanism is not suitable for binary module which use DynamicEx type PCD.\r
+# To access a dynamicEx type PCD, pair of "token space guid/token number" all need\r
+# to be specificed for PcdSet/PcdGet accessing macro.\r
+# \r
+# Platform Token Number is started from 1, and inceased continuous. From whole \r
+# platform scope, there are two zones: PEI Zone and DXE Zone\r
+# | Platform Token Number\r
+# ----------|----------------------------------------------------------------\r
+# PEI Zone: | 1 ~ PEI_LOCAL_TOKEN_NUMBER\r
+# DXE Zone: | (PEI_LOCAL_TOKEN_NUMBER + 1) ~ (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER)\r
+# \r
+# 3.2.3 Local Token Number\r
+# To fast searching a PCD entry in PCD database, PCD driver translate \r
+# platform token number to local token number via a mapping table.\r
+# For binary DynamicEx type PCD, there is a another mapping table to translate\r
+# "token space guid + token number" to local token number directly.\r
+# Local token number is identifier for all internal interface in PCD PEI/DXE\r
+# driver.\r
+# \r
+# A local token number is a 32-bit value in following meaning:\r
+# 32 ------------- 28 ---------- 24 -------- 0\r
+# | PCD type mask | Datum Type | Offset |\r
+# +-----------------------------------------+\r
+# where:\r
+# PCd type mask: indicate Pcd type from following macro:\r
+# PCD_TYPE_DATA\r
+# PCD_TYPE_HII\r
+# PCD_TYPE_VPD\r
+# PCD_TYPE_SKU_ENABLED\r
+# PCD_TYPE_STRING\r
+# Datum Type : indicate PCD vaue type from following macro:\r
+# PCD_DATUM_TYPE_POINTER\r
+# PCD_DATUM_TYPE_UINT8\r
+# PCD_DATUM_TYPE_UINT16\r
+# PCD_DATUM_TYPE_UINT32\r
+# PCD_DATUM_TYPE_UINT64\r
+# Offset : indicate the related offset of PCD value in PCD database array.\r
+# Based on local token number, PCD driver could fast determine PCD type, value\r
+# type and get PCD entry from PCD database.\r
+# \r
+# 3.3 PCD Database C structure.\r
+# PCD Database C structure is generated by build tools in PCD driver's autogen.h/\r
+# autogen.c file. In generated C structure, following information is stored:\r
+# - ExMapTable: This table is used translate a binary dynamicex type PCD's \r
+# "tokenguid + token" to local token number.\r
+# - LocalTokenNumberTable:\r
+# This table stores all local token number in array, use "Internal\r
+# token number" as array index to get PCD entry's offset fastly.\r
+# - SizeTable: This table stores the size information for all PCD entry.\r
+# - GuidTable: This table stores guid value for DynamicEx's token space,\r
+# HII type PCD's variable.\r
+# - SkuIdTable: TBD\r
+# - SystemSkuId: TBD\r
+# - PCD value structure: \r
+# Every PCD has a value record in PCD database. For different\r
+# datum type PCD has different record structure which will be \r
+# introduced in 3.3.1\r
+# \r
+# In a PCD database structure, there are two major area: Init and UnInit. \r
+# Init area is use stored above PCD internal structure such as ExMapTable, \r
+# LocalTokenNumberTable etc and the (default) value of PCD which has default \r
+# value specified in platform DSC file.\r
+# Unint area is used stored the value of PCD which has no default value in\r
+# platform DSC file, the value of NULL, 0 specified in platform DSC file can\r
+# be seemed as "no default value".\r
+# \r
+# 3.3.1 Simple Sample PCD Database C Structure\r
+# A general sample of PCD database structue is as follows:\r
+# typedef struct _PCD_DATABASE {\r
+# typedef struct _PCD_DATABASE_INIT {\r
+# //===== Following is PCD database internal maintain structures\r
+# DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE];\r
+# UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE];\r
+# GUID GuidTable[PEI_GUID_TABLE_SIZE];\r
+# SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE];\r
+# UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE];\r
+# SKU_ID SystemSkuId;\r
+# \r
+# //===== Following is value structure for PCD with default value\r
+# ....\r
+# ....\r
+# ....\r
+# } Init;\r
+# typedef struct _PCD_DATABSE_UNINIT {\r
+# //==== Following is value structure for PCD without default value\r
+# ....\r
+# ....\r
+# } UnInit;\r
+# }\r
+# \r
+# 3.3.2 PCD value structure in PCD database C structure\r
+# The value's structure is generated by build tool in PCD database C structure.\r
+# The PCDs in different datum type has different value structure.\r
+# \r
+# 3.3.2.1 UINT8/UINT16/UINT32/UINT64 datum type PCD\r
+# The C structure for these datum type PCD is just a UINT8/UINT16/UINT32/UINT64\r
+# data member in PCD database, For example:\r
+# UINT16 PcdHardwareErrorRecordLevel_d3705011_bc19_4af7_be16_f68030378c15_VariableDefault_0;\r
+# Above structure is generated by build tool, the member name is "PcdCName_Guidvalue"\r
+# Member type is UINT16 according to PcdHardwareErrorRecordLevel declaration\r
+# in DEC file.\r
+# \r
+# 3.3.2.2 VOID* datum type PCD\r
+# The value of VOID* datum type PCD is a UINT8/UINT16 array in PCD database.\r
+# \r
+# 3.3.2.2.1 VOID* - string type\r
+# If the default value for VOID* datum type PCD like L"xxx", the PCD is \r
+# used for unicode string, and C structure of this datum type PCD is \r
+# UINT16 string array in PCD database, for example:\r
+# UINT16 StringTable[29];\r
+# The number of 29 in above sample is max size of a unicode string.\r
+# \r
+# If the default value for VOID* datum type PCD like "xxx", the PCD is\r
+# used for ascii string, and C structure of this datum type PCD is \r
+# UINT8 string array in PCD database, for example:\r
+# UINT8 StringTable[20];\r
+# The number of 20 in above sample is max size of a ascii string.\r
+# \r
+# 3.3.2.2.2 VOID* - byte array\r
+# If the default value of VOID* datum type PCD like {'0x29', '0x01', '0xf2'}\r
+# the PCD is used for byte array. The generated structrue is same as \r
+# above ascii string table,\r
+# UINT8 StringTable[13];\r
+# The number of 13 in above sample is max size of byte array.\r
+# \r
+# 3.3.3 Some utility structures in PCD Database\r
+# 3.3.3.1 GuidTable\r
+# GuidTable array is used to store all related GUID value in PCD database:\r
+# - Variable GUID for HII type PCD\r
+# - Token space GUID for dynamicex type PCD \r
+#\r
# Copyright (c) 2006 - 2009, Intel Corporation\r
#\r
# All rights reserved. This program and the accompanying materials\r
\r
#endif\r
\r
-////////////////////////////////////////////////////////////////////////////////\r
-// //\r
-// Introduction of PCD database //\r
-// //\r
-////////////////////////////////////////////////////////////////////////////////\r
-/**\r
- 1, Introduction\r
- PEI PCD database hold all dynamic type PCD information used in PEI phase.\r
- The structure of PEI PCD database is generated by build tools according to\r
- dynamic PCD usage for specified platform.\r
- \r
- 2, Dynamic Type PCD\r
- Dynamic type PCD is designed for accessing setting which value is determined\r
- dynamic. In contrast, the value of static type PCD (FeatureFlag, FixedPcd, \r
- PatchablePcd) is fixed in final generated FD image in build time. \r
- \r
- 2.1 The "dynamic" determination means:\r
- a) The PCD value is produced by someone driver and consumed by other driver\r
- in execution time.\r
- b) The PCD value is set/get by user from FrontPage.\r
- c) The PCD value is produced by platform OEM specified area.\r
- \r
- 2.2 According to distribution mehod, dynamic PCD could be classfied as:\r
- a) Dynamic:\r
- This type PCD is used for module in source distribution which will be \r
- built in platform.\r
- b) DynamicEx:\r
- This type PCD is used for module in binary distribution which will be \r
- will not built.\r
- \r
- 2.3 According to storage method, dynamic PCD could be classfied as:\r
- a) Default Storage: \r
- - The value is stored in PCD database maintained by PCD database in boot \r
- time memory which is built as a guid hob in PEI phase.\r
- - This type is used for communication between PEIM/DXE driver, DXE/DXE \r
- driver. But all set/get value will be losted after boot-time memory \r
- is turn off.\r
- - [PcdsDynamicDefault]/[PcdsDynamicExDefault] is used as section name \r
- for this type PCD in platform DSC file.\r
- \r
- b) Variable Storage: \r
- - The value is stored in variable area. \r
- - As default storage type, this type PCD could used for communication.\r
- But beside it, this type PCD could be used store the value associating \r
- with HII setting via variable technology.\r
- - In PEI phase, the PCD value could only be got but can not be set due \r
- to variable area is readonly for PEI phase.\r
- - [PcdsDynamicHii]/[PcdsDynamicExHii] is used as section name for this \r
- type PCD in platform DSC file.\r
- \r
- c) OEM specificed storage area:\r
- - The value is stored in OEM specified area, the base address is specified\r
- by a FixedAtBuild PCD PcdVpdBaseAddress.\r
- - The area is read only for PEI and DXE phase.\r
- - [PcdsDynamicVpd]/[PcdsDynamicExVpd] is used as section name for this \r
- type PCD in platform DSC file.\r
- \r
- Note: The default value of dynamic PCD are storaged in memory maintained\r
- by PEI/DXE PCD drvier.\r
- \r
- 2.4 When and how to use dynamic PCD\r
- Module developer do not care the used PCD is dynamic or static when writting\r
- source code/INF. Dynamic PCD and dynamic type is pointed by platform integrator \r
- in platform DSC file. Please ref section 2.3 to get matching between dynamic\r
- PCD type and section name in DSC file.\r
- \r
- 3, PCD database:\r
- Although dynamic PCD could be in different storage type as above description, \r
- but the basic information and default value for all dynamic PCD is hold\r
- by PCD database maintained by PEI/DXE driver.\r
- \r
- As whole EFI BIOS boot path is divided into PEI/DXE phase, the PCD database\r
- also is divided into Pei/Dxe database maintaied by PcdPeim/PcdDxe driver separatly.\r
- To make PcdPeim's driver image smaller, PEI PCD database only hold all dynamic\r
- PCD information used in PEI phase or use in both PEI/DXE phase. And DXE PCD\r
- database contains all PCDs used in PEI/DXE phase in memory.\r
- \r
- Build tool will generate PCD database into some C structure and variable for \r
- PEI/DXE PCD driver according to dynamic PCD section in platform DSC file. \r
- \r
- 3.1 PcdPeim and PcdDxe\r
- PEI PCD database is maintained by PcdPeim driver run from flash. PcdPeim driver\r
- build guid hob in temporary memory and copy auto-generated C structure \r
- to temporary memory for PEI PCD database. \r
- DXE PCD database is maintained by PcdDxe driver.At entry point of PcdDxe driver,\r
- a new PCD database is allocated in boot-time memory which including all\r
- PEI PCD and DXE PCD entry.\r
- \r
- Pcd driver should run as early as possible before any other driver access\r
- dynamic PCD's value. PEI/DXE "Apriori File" mechanism make it possible by\r
- making PcdPeim/PcdDxe as first dispatching driver in PEI/DXE phase.\r
- \r
- 3.2 Token space Guid/Token number, Platform token, Local token number\r
- Dynamic PCD\r
- +-----------+ +---------+\r
- |TokenSpace | |Platform |\r
- | Guid | build tool | Token |\r
- | + +-------------->| Number |\r
- | Token | +---------+`._\r
- | Number | `.\r
- +-----------+ `. +------+\r
- `-|Local |\r
- |Token |\r
- DynamicEx PCD ,-|Number|\r
- +-----------+ ,-' +------+\r
- |TokenSpace | ,-'\r
- | Guid | _,-'\r
- | + +.'\r
- | Token |\r
- | Number |\r
- +-----------+\r
- \r
- \r
- 3.2.1 Pair of Token space guid + Token number\r
- Any type PCD is identified by pair of "TokenSpaceGuid + TokeNumber". But it\r
- is not easy maintained by PCD driver, and hashed token number will make \r
- searching slowly. \r
-\r
- 3.2.2 Platform Token Number\r
- "Platform token number" concept is introduced for mapping to a pair of \r
- "TokenSpaceGuid + TokenNumber". The platform token number is generated by \r
- build tool in autogen.h and all of them are continual in a platform scope \r
- started from 1.(0 meaning invalid internal token number)\r
- With auto-generated "platform token number", PcdGet(PcdSampleDynamicPcd)\r
- in source code is translated to LibPcdGet(_PCD_TOKEN_PcdSampleDynamicPcd) \r
- in autogen.h.\r
- Notes: The mapping between pair of "tokenspace guid + token number" and\r
- "internal token number" need build tool establish, so "platform token number"\r
- mechanism is not suitable for binary module which use DynamicEx type PCD.\r
- To access a dynamicEx type PCD, pair of "token space guid/token number" all need\r
- to be specificed for PcdSet/PcdGet accessing macro.\r
- \r
- Platform Token Number is started from 1, and inceased continuous. From whole \r
- platform scope, there are two zones: PEI Zone and DXE Zone\r
- | Platform Token Number\r
- ----------|----------------------------------------------------------------\r
- PEI Zone: | 1 ~ PEI_LOCAL_TOKEN_NUMBER\r
- DXE Zone: | (PEI_LOCAL_TOKEN_NUMBER + 1) ~ (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER)\r
- \r
- 3.2.3 Local Token Number\r
- To fast searching a PCD entry in PCD database, PCD driver translate \r
- platform token number to local token number via a mapping table.\r
- For binary DynamicEx type PCD, there is a another mapping table to translate\r
- "token space guid + token number" to local token number directly.\r
- Local token number is identifier for all internal interface in PCD PEI/DXE\r
- driver.\r
- \r
- A local token number is a 32-bit value in following meaning:\r
- 32 ------------- 28 ---------- 24 -------- 0\r
- | PCD type mask | Datum Type | Offset |\r
- +-----------------------------------------+\r
- where:\r
- PCd type mask: indicate Pcd type from following macro:\r
- PCD_TYPE_DATA\r
- PCD_TYPE_HII\r
- PCD_TYPE_VPD\r
- PCD_TYPE_SKU_ENABLED\r
- PCD_TYPE_STRING\r
- Datum Type : indicate PCD vaue type from following macro:\r
- PCD_DATUM_TYPE_POINTER\r
- PCD_DATUM_TYPE_UINT8\r
- PCD_DATUM_TYPE_UINT16\r
- PCD_DATUM_TYPE_UINT32\r
- PCD_DATUM_TYPE_UINT64\r
- Offset : indicate the related offset of PCD value in PCD database array.\r
- Based on local token number, PCD driver could fast determine PCD type, value\r
- type and get PCD entry from PCD database.\r
- \r
- 3.3 PCD Database C structure.\r
- PCD Database C structure is generated by build tools in PCD driver's autogen.h/\r
- autogen.c file. In generated C structure, following information is stored:\r
- - ExMapTable: This table is used translate a binary dynamicex type PCD's \r
- "tokenguid + token" to local token number.\r
- - LocalTokenNumberTable:\r
- This table stores all local token number in array, use "Internal\r
- token number" as array index to get PCD entry's offset fastly.\r
- - SizeTable: This table stores the size information for all PCD entry.\r
- - GuidTable: This table stores guid value for DynamicEx's token space,\r
- HII type PCD's variable.\r
- - SkuIdTable: TBD\r
- - SystemSkuId: TBD\r
- - PCD value structure: \r
- Every PCD has a value record in PCD database. For different\r
- datum type PCD has different record structure which will be \r
- introduced in 3.3.1\r
- \r
- In a PCD database structure, there are two major area: Init and UnInit. \r
- Init area is use stored above PCD internal structure such as ExMapTable, \r
- LocalTokenNumberTable etc and the (default) value of PCD which has default \r
- value specified in platform DSC file.\r
- Unint area is used stored the value of PCD which has no default value in\r
- platform DSC file, the value of NULL, 0 specified in platform DSC file can\r
- be seemed as "no default value".\r
- \r
- 3.3.1 Simple Sample PCD Database C Structure\r
- A general sample of PCD database structue is as follows:\r
- typedef struct _PCD_DATABASE {\r
- typedef struct _PCD_DATABASE_INIT {\r
- //===== Following is PCD database internal maintain structures\r
- DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE];\r
- UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE];\r
- GUID GuidTable[PEI_GUID_TABLE_SIZE];\r
- SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE];\r
- UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE];\r
- SKU_ID SystemSkuId;\r
- \r
- //===== Following is value structure for PCD with default value\r
- ....\r
- ....\r
- ....\r
- } Init;\r
- typedef struct _PCD_DATABSE_UNINIT {\r
- //==== Following is value structure for PCD without default value\r
- ....\r
- ....\r
- } UnInit;\r
- }\r
- \r
- 3.3.2 PCD value structure in PCD database C structure\r
- The value's structure is generated by build tool in PCD database C structure.\r
- The PCDs in different datum type has different value structure.\r
- \r
- 3.3.2.1 UINT8/UINT16/UINT32/UINT64 datum type PCD\r
- The C structure for these datum type PCD is just a UINT8/UINT16/UINT32/UINT64\r
- data member in PCD database, For example:\r
- UINT16 PcdHardwareErrorRecordLevel_d3705011_bc19_4af7_be16_f68030378c15_VariableDefault_0;\r
- Above structure is generated by build tool, the member name is "PcdCName_Guidvalue"\r
- Member type is UINT16 according to PcdHardwareErrorRecordLevel declaration\r
- in DEC file.\r
- \r
- 3.3.2.2 VOID* datum type PCD\r
- The value of VOID* datum type PCD is a UINT8/UINT16 array in PCD database.\r
- \r
- 3.3.2.2.1 VOID* - string type\r
- If the default value for VOID* datum type PCD like L"xxx", the PCD is \r
- used for unicode string, and C structure of this datum type PCD is \r
- UINT16 string array in PCD database, for example:\r
- UINT16 StringTable[29];\r
- The number of 29 in above sample is max size of a unicode string.\r
- \r
- If the default value for VOID* datum type PCD like "xxx", the PCD is\r
- used for ascii string, and C structure of this datum type PCD is \r
- UINT8 string array in PCD database, for example:\r
- UINT8 StringTable[20];\r
- The number of 20 in above sample is max size of a ascii string.\r
- \r
- 3.3.2.2.2 VOID* - byte array\r
- If the default value of VOID* datum type PCD like {'0x29', '0x01', '0xf2'}\r
- the PCD is used for byte array. The generated structrue is same as \r
- above ascii string table,\r
- UINT8 StringTable[13];\r
- The number of 13 in above sample is max size of byte array.\r
- \r
- 3.3.3 Some utility structures in PCD Database\r
- 3.3.3.1 GuidTable\r
- GuidTable array is used to store all related GUID value in PCD database:\r
- - Variable GUID for HII type PCD\r
- - Token space GUID for dynamicex type PCD \r
- \r
- 3.4 PEI PCD Database \r
- \r
-**/\r
#/** @file\r
# PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service.\r
#\r
+# ////////////////////////////////////////////////////////////////////////////////\r
+# // //\r
+# // Introduction of PCD database //\r
+# // //\r
+# ////////////////////////////////////////////////////////////////////////////////\r
+#\r
+# 1, Introduction\r
+# PCD database hold all dynamic type PCD information. The structure of PEI PCD \r
+# database is generated by build tools according to dynamic PCD usage for \r
+# specified platform.\r
+# \r
+# 2, Dynamic Type PCD\r
+# Dynamic type PCD is used for the configuration/setting which value is determined\r
+# dynamic. In contrast, the value of static type PCD (FeatureFlag, FixedPcd, \r
+# PatchablePcd) is fixed in final generated FD image in build time. \r
+# \r
+# 2.1 The "dynamic" determination means one of below cases:\r
+# a) The PCD setting value is produced by someone driver and consumed by \r
+# other driver in execution time.\r
+# b) The PCD setting value is set/get by user from FrontPage.\r
+# c) The PCD setting value is produced by platform OEM vendor in specified area.\r
+# \r
+# 2.2 According to module distribution way, dynamic PCD could be classfied as:\r
+# a) Dynamic:\r
+# If module is released in source code and will be built with platform \r
+# DSC, the dynamic PCD used by this module can be accessed as:\r
+# PcdGetxx(PcdSampleDynamicPcd); \r
+# In building platform, build tools will translate PcdSampleDynamicPcd to\r
+# pair of {Token Space Guid: Token Number} for this PCD. \r
+# b) DynamicEx:\r
+# If module is release as binary and will not pariticpate platform building,\r
+# the dynamic PCD used by this module need be accessed as:\r
+# PcdGetxxEx(gEfiMyTokenspaceGuid, PcdSampleDynamicPcd)\r
+# Developer need explicity gives {Token Space Guid:Token Number} as parameter\r
+# in writting source code.\r
+# \r
+# 2.3 According to PCD value's storage method, dynamic PCD could be classfied as:\r
+# a) Default Storage: \r
+# - The PCD value is stored in PCD database maintained by PCD driver in boot \r
+# time memory.\r
+# - This type is used for communication between PEIM/DXE driver, DXE/DXE \r
+# driver. But all set/get value will be losted after boot-time memory \r
+# is turn off.\r
+# - [PcdsDynamicDefault] is used as section name for this type PCD in \r
+# platform DSC file. [PcdsDynamicExDefault] is used for dynamicEx type PCD.\r
+# \r
+# b) Variable Storage: \r
+# - The PCD value is stored in variable area. \r
+# - As default storage type, this type PCD could be used for PEI/DXE driver\r
+# communication. But beside it, this type PCD could alsp be used to store \r
+# the value associate with a HII setting via variable interface.\r
+# - In PEI phase, the PCD value could only be got but can not be set due \r
+# to variable area is readonly.\r
+# - [PcdsDynamicHii] is used as section name for this type PCD in platform \r
+# DSC file. [PcdsDynamicExHii] is for dynamicEx type PCD.\r
+# \r
+# c) OEM specificed storage area:\r
+# - The PCD value is stored in OEM specified area which base address is \r
+# specified by a FixedAtBuild PCD setting - PcdVpdBaseAddress.\r
+# - The area is read only for PEI and DXE phase.\r
+# - [PcdsDynamicVpd] is used as section name for this type PCD in platform \r
+# DSC file. [PcdsDynamicExVpd] is for dynamicex type PCD.\r
+# \r
+# 2.4 When and how to use dynamic PCD\r
+# Module developer do not care the used PCD is dynamic or static when writting\r
+# source code/INF. Dynamic PCD and dynamic type is pointed by platform integrator \r
+# in platform DSC file. Please ref section 2.3 to get matching between dynamic\r
+# PCD type and section name in DSC file.\r
+# \r
+# 3, PCD database:\r
+# Although dynamic PCD could be in different storage type as above description, \r
+# but the basic information and default value for all dynamic PCD is hold\r
+# by PCD database maintained by PEI/DXE driver.\r
+# \r
+# As the whole EFI BIOS boot path is divided into PEI/DXE phase, the PCD database\r
+# also is divided into Pei/Dxe database maintaied by PcdPeim/PcdDxe driver separatly.\r
+# To make PcdPeim's driver image smaller, PEI PCD database only hold all dynamic\r
+# PCD information used in PEI phase or use in both PEI/DXE phase. And DXE PCD\r
+# database contains all PCDs used in PEI/DXE phase in memory.\r
+# \r
+# Build tool will generate PCD database into some C structure and variable for \r
+# PEI/DXE PCD driver according to dynamic PCD section in platform DSC file. \r
+# \r
+# 3.1 PcdPeim and PcdDxe\r
+# PEI PCD database is maintained by PcdPeim driver run from flash. PcdPeim driver\r
+# build guid hob in temporary memory and copy auto-generated C structure \r
+# to temporary memory for PEI PCD database. \r
+# DXE PCD database is maintained by PcdDxe driver.At entry point of PcdDxe driver,\r
+# a new PCD database is allocated in boot-time memory which including all\r
+# PEI PCD and DXE PCD entry.\r
+# \r
+# Pcd driver should run as early as possible before any other driver access\r
+# dynamic PCD's value. PEI/DXE "Apriori File" mechanism make it possible by\r
+# making PcdPeim/PcdDxe as first dispatching driver in PEI/DXE phase.\r
+# \r
+# 3.2 Token space Guid/Token number, Platform token, Local token number\r
+# Dynamic PCD\r
+# +-----------+ +---------+\r
+# |TokenSpace | |Platform |\r
+# | Guid | build tool | Token |\r
+# | + +-------------->| Number |\r
+# | Token | +---------+`._\r
+# | Number | `.\r
+# +-----------+ `. +------+\r
+# `-|Local |\r
+# |Token |\r
+# DynamicEx PCD ,-|Number|\r
+# +-----------+ ,-' +------+\r
+# |TokenSpace | ,-'\r
+# | Guid | _,-'\r
+# | + +.'\r
+# | Token |\r
+# | Number |\r
+# +-----------+\r
+# \r
+# \r
+# 3.2.1 Pair of Token space guid + Token number\r
+# Any type PCD is identified by pair of "TokenSpaceGuid + TokeNumber". But it\r
+# is not easy maintained by PCD driver, and hashed token number will make \r
+# searching slowly. \r
+#\r
+# 3.2.2 Platform Token Number\r
+# "Platform token number" concept is introduced for mapping to a pair of \r
+# "TokenSpaceGuid + TokenNumber". The platform token number is generated by \r
+# build tool in autogen.h and all of them are continual in a platform scope \r
+# started from 1.(0 meaning invalid internal token number)\r
+# With auto-generated "platform token number", PcdGet(PcdSampleDynamicPcd)\r
+# in source code is translated to LibPcdGet(_PCD_TOKEN_PcdSampleDynamicPcd) \r
+# in autogen.h.\r
+# Notes: The mapping between pair of "tokenspace guid + token number" and\r
+# "internal token number" need build tool establish, so "platform token number"\r
+# mechanism is not suitable for binary module which use DynamicEx type PCD.\r
+# To access a dynamicEx type PCD, pair of "token space guid/token number" all need\r
+# to be specificed for PcdSet/PcdGet accessing macro.\r
+# \r
+# Platform Token Number is started from 1, and inceased continuous. From whole \r
+# platform scope, there are two zones: PEI Zone and DXE Zone\r
+# | Platform Token Number\r
+# ----------|----------------------------------------------------------------\r
+# PEI Zone: | 1 ~ PEI_LOCAL_TOKEN_NUMBER\r
+# DXE Zone: | (PEI_LOCAL_TOKEN_NUMBER + 1) ~ (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER)\r
+# \r
+# 3.2.3 Local Token Number\r
+# To fast searching a PCD entry in PCD database, PCD driver translate \r
+# platform token number to local token number via a mapping table.\r
+# For binary DynamicEx type PCD, there is a another mapping table to translate\r
+# "token space guid + token number" to local token number directly.\r
+# Local token number is identifier for all internal interface in PCD PEI/DXE\r
+# driver.\r
+# \r
+# A local token number is a 32-bit value in following meaning:\r
+# 32 ------------- 28 ---------- 24 -------- 0\r
+# | PCD type mask | Datum Type | Offset |\r
+# +-----------------------------------------+\r
+# where:\r
+# PCd type mask: indicate Pcd type from following macro:\r
+# PCD_TYPE_DATA\r
+# PCD_TYPE_HII\r
+# PCD_TYPE_VPD\r
+# PCD_TYPE_SKU_ENABLED\r
+# PCD_TYPE_STRING\r
+# Datum Type : indicate PCD vaue type from following macro:\r
+# PCD_DATUM_TYPE_POINTER\r
+# PCD_DATUM_TYPE_UINT8\r
+# PCD_DATUM_TYPE_UINT16\r
+# PCD_DATUM_TYPE_UINT32\r
+# PCD_DATUM_TYPE_UINT64\r
+# Offset : indicate the related offset of PCD value in PCD database array.\r
+# Based on local token number, PCD driver could fast determine PCD type, value\r
+# type and get PCD entry from PCD database.\r
+# \r
+# 3.3 PCD Database C structure.\r
+# PCD Database C structure is generated by build tools in PCD driver's autogen.h/\r
+# autogen.c file. In generated C structure, following information is stored:\r
+# - ExMapTable: This table is used translate a binary dynamicex type PCD's \r
+# "tokenguid + token" to local token number.\r
+# - LocalTokenNumberTable:\r
+# This table stores all local token number in array, use "Internal\r
+# token number" as array index to get PCD entry's offset fastly.\r
+# - SizeTable: This table stores the size information for all PCD entry.\r
+# - GuidTable: This table stores guid value for DynamicEx's token space,\r
+# HII type PCD's variable.\r
+# - SkuIdTable: TBD\r
+# - SystemSkuId: TBD\r
+# - PCD value structure: \r
+# Every PCD has a value record in PCD database. For different\r
+# datum type PCD has different record structure which will be \r
+# introduced in 3.3.1\r
+# \r
+# In a PCD database structure, there are two major area: Init and UnInit. \r
+# Init area is use stored above PCD internal structure such as ExMapTable, \r
+# LocalTokenNumberTable etc and the (default) value of PCD which has default \r
+# value specified in platform DSC file.\r
+# Unint area is used stored the value of PCD which has no default value in\r
+# platform DSC file, the value of NULL, 0 specified in platform DSC file can\r
+# be seemed as "no default value".\r
+# \r
+# 3.3.1 Simple Sample PCD Database C Structure\r
+# A general sample of PCD database structue is as follows:\r
+# typedef struct _PCD_DATABASE {\r
+# typedef struct _PCD_DATABASE_INIT {\r
+# //===== Following is PCD database internal maintain structures\r
+# DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE];\r
+# UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE];\r
+# GUID GuidTable[PEI_GUID_TABLE_SIZE];\r
+# SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE];\r
+# UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE];\r
+# SKU_ID SystemSkuId;\r
+# \r
+# //===== Following is value structure for PCD with default value\r
+# ....\r
+# ....\r
+# ....\r
+# } Init;\r
+# typedef struct _PCD_DATABSE_UNINIT {\r
+# //==== Following is value structure for PCD without default value\r
+# ....\r
+# ....\r
+# } UnInit;\r
+# }\r
+# \r
+# 3.3.2 PCD value structure in PCD database C structure\r
+# The value's structure is generated by build tool in PCD database C structure.\r
+# The PCDs in different datum type has different value structure.\r
+# \r
+# 3.3.2.1 UINT8/UINT16/UINT32/UINT64 datum type PCD\r
+# The C structure for these datum type PCD is just a UINT8/UINT16/UINT32/UINT64\r
+# data member in PCD database, For example:\r
+# UINT16 PcdHardwareErrorRecordLevel_d3705011_bc19_4af7_be16_f68030378c15_VariableDefault_0;\r
+# Above structure is generated by build tool, the member name is "PcdCName_Guidvalue"\r
+# Member type is UINT16 according to PcdHardwareErrorRecordLevel declaration\r
+# in DEC file.\r
+# \r
+# 3.3.2.2 VOID* datum type PCD\r
+# The value of VOID* datum type PCD is a UINT8/UINT16 array in PCD database.\r
+# \r
+# 3.3.2.2.1 VOID* - string type\r
+# If the default value for VOID* datum type PCD like L"xxx", the PCD is \r
+# used for unicode string, and C structure of this datum type PCD is \r
+# UINT16 string array in PCD database, for example:\r
+# UINT16 StringTable[29];\r
+# The number of 29 in above sample is max size of a unicode string.\r
+# \r
+# If the default value for VOID* datum type PCD like "xxx", the PCD is\r
+# used for ascii string, and C structure of this datum type PCD is \r
+# UINT8 string array in PCD database, for example:\r
+# UINT8 StringTable[20];\r
+# The number of 20 in above sample is max size of a ascii string.\r
+# \r
+# 3.3.2.2.2 VOID* - byte array\r
+# If the default value of VOID* datum type PCD like {'0x29', '0x01', '0xf2'}\r
+# the PCD is used for byte array. The generated structrue is same as \r
+# above ascii string table,\r
+# UINT8 StringTable[13];\r
+# The number of 13 in above sample is max size of byte array.\r
+# \r
+# 3.3.3 Some utility structures in PCD Database\r
+# 3.3.3.1 GuidTable\r
+# GuidTable array is used to store all related GUID value in PCD database:\r
+# - Variable GUID for HII type PCD\r
+# - Token space GUID for dynamicex type PCD \r
+# \r
# Copyright (c) 2006 - 2008, Intel Corporation\r
#\r
# All rights reserved. This program and the accompanying materials\r
\r
#endif\r
\r
-////////////////////////////////////////////////////////////////////////////////\r
-// //\r
-// Introduction of PCD database //\r
-// //\r
-////////////////////////////////////////////////////////////////////////////////\r
-/**\r
- 1, Introduction\r
- PEI PCD database hold all dynamic type PCD information used in PEI phase.\r
- The structure of PEI PCD database is generated by build tools according to\r
- dynamic PCD usage for specified platform.\r
- \r
- 2, Dynamic Type PCD\r
- Dynamic type PCD is designed for accessing setting which value is determined\r
- dynamic. In contrast, the value of static type PCD (FeatureFlag, FixedPcd, \r
- PatchablePcd) is fixed in final generated FD image in build time. \r
- \r
- 2.1 The "dynamic" determination means:\r
- a) The PCD value is produced by someone driver and consumed by other driver\r
- in execution time.\r
- b) The PCD value is set/get by user from FrontPage.\r
- c) The PCD value is produced by platform OEM specified area.\r
- \r
- 2.2 According to distribution mehod, dynamic PCD could be classfied as:\r
- a) Dynamic:\r
- This type PCD is used for module in source distribution which will be \r
- built in platform.\r
- b) DynamicEx:\r
- This type PCD is used for module in binary distribution which will be \r
- will not built.\r
- \r
- 2.3 According to storage method, dynamic PCD could be classfied as:\r
- a) Default Storage: \r
- - The value is stored in PCD database maintained by PCD database in boot \r
- time memory which is built as a guid hob in PEI phase.\r
- - This type is used for communication between PEIM/DXE driver, DXE/DXE \r
- driver. But all set/get value will be losted after boot-time memory \r
- is turn off.\r
- - [PcdsDynamicDefault]/[PcdsDynamicExDefault] is used as section name \r
- for this type PCD in platform DSC file.\r
- \r
- b) Variable Storage: \r
- - The value is stored in variable area. \r
- - As default storage type, this type PCD could used for communication.\r
- But beside it, this type PCD could be used store the value associating \r
- with HII setting via variable technology.\r
- - In PEI phase, the PCD value could only be got but can not be set due \r
- to variable area is readonly for PEI phase.\r
- - [PcdsDynamicHii]/[PcdsDynamicExHii] is used as section name for this \r
- type PCD in platform DSC file.\r
- \r
- c) OEM specificed storage area:\r
- - The value is stored in OEM specified area, the base address is specified\r
- by a FixedAtBuild PCD PcdVpdBaseAddress.\r
- - The area is read only for PEI and DXE phase.\r
- - [PcdsDynamicVpd]/[PcdsDynamicExVpd] is used as section name for this \r
- type PCD in platform DSC file.\r
- \r
- Note: The default value of dynamic PCD are storaged in memory maintained\r
- by PEI/DXE PCD drvier.\r
- \r
- 2.4 When and how to use dynamic PCD\r
- Module developer do not care the used PCD is dynamic or static when writting\r
- source code/INF. Dynamic PCD and dynamic type is pointed by platform integrator \r
- in platform DSC file. Please ref section 2.3 to get matching between dynamic\r
- PCD type and section name in DSC file.\r
- \r
- 3, PCD database:\r
- Although dynamic PCD could be in different storage type as above description, \r
- but the basic information and default value for all dynamic PCD is hold\r
- by PCD database maintained by PEI/DXE driver.\r
- \r
- As whole EFI BIOS boot path is divided into PEI/DXE phase, the PCD database\r
- also is divided into Pei/Dxe database maintaied by PcdPeim/PcdDxe driver separatly.\r
- To make PcdPeim's driver image smaller, PEI PCD database only hold all dynamic\r
- PCD information used in PEI phase or use in both PEI/DXE phase. And DXE PCD\r
- database contains all PCDs used in PEI/DXE phase in memory.\r
- \r
- Build tool will generate PCD database into some C structure and variable for \r
- PEI/DXE PCD driver according to dynamic PCD section in platform DSC file. \r
- \r
- 3.1 PcdPeim and PcdDxe\r
- PEI PCD database is maintained by PcdPeim driver run from flash. PcdPeim driver\r
- build guid hob in temporary memory and copy auto-generated C structure \r
- to temporary memory for PEI PCD database. \r
- DXE PCD database is maintained by PcdDxe driver.At entry point of PcdDxe driver,\r
- a new PCD database is allocated in boot-time memory which including all\r
- PEI PCD and DXE PCD entry.\r
- \r
- Pcd driver should run as early as possible before any other driver access\r
- dynamic PCD's value. PEI/DXE "Apriori File" mechanism make it possible by\r
- making PcdPeim/PcdDxe as first dispatching driver in PEI/DXE phase.\r
- \r
- 3.2 Token space Guid/Token number, Platform token, Local token number\r
- Dynamic PCD\r
- +-----------+ +---------+\r
- |TokenSpace | |Platform |\r
- | Guid | build tool | Token |\r
- | + +-------------->| Number |\r
- | Token | +---------+`._\r
- | Number | `.\r
- +-----------+ `. +------+\r
- `-|Local |\r
- |Token |\r
- DynamicEx PCD ,-|Number|\r
- +-----------+ ,-' +------+\r
- |TokenSpace | ,-'\r
- | Guid | _,-'\r
- | + +.'\r
- | Token |\r
- | Number |\r
- +-----------+\r
- \r
- \r
- 3.2.1 Pair of Token space guid + Token number\r
- Any type PCD is identified by pair of "TokenSpaceGuid + TokeNumber". But it\r
- is not easy maintained by PCD driver, and hashed token number will make \r
- searching slowly. \r
-\r
- 3.2.2 Platform Token Number\r
- "Platform token number" concept is introduced for mapping to a pair of \r
- "TokenSpaceGuid + TokenNumber". The platform token number is generated by \r
- build tool in autogen.h and all of them are continual in a platform scope \r
- started from 1.(0 meaning invalid internal token number)\r
- With auto-generated "platform token number", PcdGet(PcdSampleDynamicPcd)\r
- in source code is translated to LibPcdGet(_PCD_TOKEN_PcdSampleDynamicPcd) \r
- in autogen.h.\r
- Notes: The mapping between pair of "tokenspace guid + token number" and\r
- "internal token number" need build tool establish, so "platform token number"\r
- mechanism is not suitable for binary module which use DynamicEx type PCD.\r
- To access a dynamicEx type PCD, pair of "token space guid/token number" all need\r
- to be specificed for PcdSet/PcdGet accessing macro.\r
- \r
- Platform Token Number is started from 1, and inceased continuous. From whole \r
- platform scope, there are two zones: PEI Zone and DXE Zone\r
- | Platform Token Number\r
- ----------|----------------------------------------------------------------\r
- PEI Zone: | 1 ~ PEI_LOCAL_TOKEN_NUMBER\r
- DXE Zone: | (PEI_LOCAL_TOKEN_NUMBER + 1) ~ (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER)\r
- \r
- 3.2.3 Local Token Number\r
- To fast searching a PCD entry in PCD database, PCD driver translate \r
- platform token number to local token number via a mapping table.\r
- For binary DynamicEx type PCD, there is a another mapping table to translate\r
- "token space guid + token number" to local token number directly.\r
- Local token number is identifier for all internal interface in PCD PEI/DXE\r
- driver.\r
- \r
- A local token number is a 32-bit value in following meaning:\r
- 32 ------------- 28 ---------- 24 -------- 0\r
- | PCD type mask | Datum Type | Offset |\r
- +-----------------------------------------+\r
- where:\r
- PCd type mask: indicate Pcd type from following macro:\r
- PCD_TYPE_DATA\r
- PCD_TYPE_HII\r
- PCD_TYPE_VPD\r
- PCD_TYPE_SKU_ENABLED\r
- PCD_TYPE_STRING\r
- Datum Type : indicate PCD vaue type from following macro:\r
- PCD_DATUM_TYPE_POINTER\r
- PCD_DATUM_TYPE_UINT8\r
- PCD_DATUM_TYPE_UINT16\r
- PCD_DATUM_TYPE_UINT32\r
- PCD_DATUM_TYPE_UINT64\r
- Offset : indicate the related offset of PCD value in PCD database array.\r
- Based on local token number, PCD driver could fast determine PCD type, value\r
- type and get PCD entry from PCD database.\r
- \r
- 3.3 PCD Database C structure.\r
- PCD Database C structure is generated by build tools in PCD driver's autogen.h/\r
- autogen.c file. In generated C structure, following information is stored:\r
- - ExMapTable: This table is used translate a binary dynamicex type PCD's \r
- "tokenguid + token" to local token number.\r
- - LocalTokenNumberTable:\r
- This table stores all local token number in array, use "Internal\r
- token number" as array index to get PCD entry's offset fastly.\r
- - SizeTable: This table stores the size information for all PCD entry.\r
- - GuidTable: This table stores guid value for DynamicEx's token space,\r
- HII type PCD's variable.\r
- - SkuIdTable: TBD\r
- - SystemSkuId: TBD\r
- - PCD value structure: \r
- Every PCD has a value record in PCD database. For different\r
- datum type PCD has different record structure which will be \r
- introduced in 3.3.1\r
- \r
- In a PCD database structure, there are two major area: Init and UnInit. \r
- Init area is use stored above PCD internal structure such as ExMapTable, \r
- LocalTokenNumberTable etc and the (default) value of PCD which has default \r
- value specified in platform DSC file.\r
- Unint area is used stored the value of PCD which has no default value in\r
- platform DSC file, the value of NULL, 0 specified in platform DSC file can\r
- be seemed as "no default value".\r
- \r
- 3.3.1 Simple Sample PCD Database C Structure\r
- A general sample of PCD database structue is as follows:\r
- typedef struct _PCD_DATABASE {\r
- typedef struct _PCD_DATABASE_INIT {\r
- //===== Following is PCD database internal maintain structures\r
- DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE];\r
- UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE];\r
- GUID GuidTable[PEI_GUID_TABLE_SIZE];\r
- SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE];\r
- UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE];\r
- SKU_ID SystemSkuId;\r
- \r
- //===== Following is value structure for PCD with default value\r
- ....\r
- ....\r
- ....\r
- } Init;\r
- typedef struct _PCD_DATABSE_UNINIT {\r
- //==== Following is value structure for PCD without default value\r
- ....\r
- ....\r
- } UnInit;\r
- }\r
- \r
- 3.3.2 PCD value structure in PCD database C structure\r
- The value's structure is generated by build tool in PCD database C structure.\r
- The PCDs in different datum type has different value structure.\r
- \r
- 3.3.2.1 UINT8/UINT16/UINT32/UINT64 datum type PCD\r
- The C structure for these datum type PCD is just a UINT8/UINT16/UINT32/UINT64\r
- data member in PCD database, For example:\r
- UINT16 PcdHardwareErrorRecordLevel_d3705011_bc19_4af7_be16_f68030378c15_VariableDefault_0;\r
- Above structure is generated by build tool, the member name is "PcdCName_Guidvalue"\r
- Member type is UINT16 according to PcdHardwareErrorRecordLevel declaration\r
- in DEC file.\r
- \r
- 3.3.2.2 VOID* datum type PCD\r
- The value of VOID* datum type PCD is a UINT8/UINT16 array in PCD database.\r
- \r
- 3.3.2.2.1 VOID* - string type\r
- If the default value for VOID* datum type PCD like L"xxx", the PCD is \r
- used for unicode string, and C structure of this datum type PCD is \r
- UINT16 string array in PCD database, for example:\r
- UINT16 StringTable[29];\r
- The number of 29 in above sample is max size of a unicode string.\r
- \r
- If the default value for VOID* datum type PCD like "xxx", the PCD is\r
- used for ascii string, and C structure of this datum type PCD is \r
- UINT8 string array in PCD database, for example:\r
- UINT8 StringTable[20];\r
- The number of 20 in above sample is max size of a ascii string.\r
- \r
- 3.3.2.2.2 VOID* - byte array\r
- If the default value of VOID* datum type PCD like {'0x29', '0x01', '0xf2'}\r
- the PCD is used for byte array. The generated structrue is same as \r
- above ascii string table,\r
- UINT8 StringTable[13];\r
- The number of 13 in above sample is max size of byte array.\r
- \r
- 3.3.3 Some utility structures in PCD Database\r
- 3.3.3.1 GuidTable\r
- GuidTable array is used to store all related GUID value in PCD database:\r
- - Variable GUID for HII type PCD\r
- - Token space GUID for dynamicex type PCD \r
- \r
-**/\r
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