From: klu2 Date: Sun, 29 Mar 2009 11:20:12 +0000 (+0000) Subject: Add introduction of PCD database in PCD Database. X-Git-Tag: edk2-stable201903~18288 X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=cf84d2671a085e4f9951bb039967fe5444219115 Add introduction of PCD database in PCD Database. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7974 6f19259b-4bc3-4df7-8a09-765794883524 --- diff --git a/MdeModulePkg/Universal/PCD/Dxe/Service.h b/MdeModulePkg/Universal/PCD/Dxe/Service.h index 04f317084b..2a1f71981c 100644 --- a/MdeModulePkg/Universal/PCD/Dxe/Service.h +++ b/MdeModulePkg/Universal/PCD/Dxe/Service.h @@ -1066,299 +1066,265 @@ extern EFI_LOCK mPcdDatabaseLock; #endif -//////////////////////////////////////////////////////////////////////////////////////////////////// -/// /// -/// Following code is an example for auto-generated PCD database to hold all dynamic/dynamicex /// -/// PCD's value for one given platform. And following sample comes from autogen.h/autogen.c of /// -/// PCD Dxe driver for NT32 platform. /// -/// /// -/// The PCD database is stored into a big structure - PCD_DATABASE which is consisted of /// -/// PEI PCD database structure and DXE PCD database structure. /// -/// /// -//////////////////////////////////////////////////////////////////////////////////////////////////// - -// // -// // Common definitions -// // -// typedef UINT8 SKU_ID; -// -// // -// // A PCD offset value is consisted as follows: -// // 32 ------------- 28 ---------- 24 -------- 0 -// // | PCD type mask | Datum Type | Offset | -// // ------------------------------------------- -// -// #define PCD_TYPE_SHIFT 28 // 28 ~ 32 bit hold PCD type information -// -// #define PCD_TYPE_DATA (0x0 << PCD_TYPE_SHIFT) -// #define PCD_TYPE_HII (0x8 << PCD_TYPE_SHIFT) -// #define PCD_TYPE_VPD (0x4 << PCD_TYPE_SHIFT) -// #define PCD_TYPE_SKU_ENABLED (0x2 << PCD_TYPE_SHIFT) -// #define PCD_TYPE_STRING (0x1 << PCD_TYPE_SHIFT) -// -// #define PCD_TYPE_ALL_SET (PCD_TYPE_DATA | PCD_TYPE_HII | PCD_TYPE_VPD | PCD_TYPE_SKU_ENABLED | PCD_TYPE_STRING) -// -// #define PCD_DATUM_TYPE_SHIFT 24 // 24 ~ 28 bit hold datum type information -// -// #define PCD_DATUM_TYPE_POINTER (0x0 << PCD_DATUM_TYPE_SHIFT) -// #define PCD_DATUM_TYPE_UINT8 (0x1 << PCD_DATUM_TYPE_SHIFT) -// #define PCD_DATUM_TYPE_UINT16 (0x2 << PCD_DATUM_TYPE_SHIFT) -// #define PCD_DATUM_TYPE_UINT32 (0x4 << PCD_DATUM_TYPE_SHIFT) -// #define PCD_DATUM_TYPE_UINT64 (0x8 << PCD_DATUM_TYPE_SHIFT) -// -// #define PCD_DATUM_TYPE_ALL_SET (PCD_DATUM_TYPE_POINTER | -// PCD_DATUM_TYPE_UINT8 | -// PCD_DATUM_TYPE_UINT16 | -// PCD_DATUM_TYPE_UINT32 | -// PCD_DATUM_TYPE_UINT64) -// -// #define PCD_DATABASE_OFFSET_MASK (~(PCD_TYPE_ALL_SET | PCD_DATUM_TYPE_ALL_SET)) -// -// typedef struct { -// UINT32 ExTokenNumber; -// UINT16 LocalTokenNumber; // PCD Number of this particular platform build -// UINT16 ExGuidIndex; // Index of GuidTable -// } DYNAMICEX_MAPPING; -// -// typedef struct { -// UINT32 SkuDataStartOffset; //We have to use offsetof MACRO as we don't know padding done by compiler -// UINT32 SkuIdTableOffset; //Offset from the PCD_DB -// } SKU_HEAD; -// -// typedef struct { -// UINT16 GuidTableIndex; // Offset in Guid Table in units of GUID. -// UINT16 StringIndex; // Offset in String Table in units of UINT16. -// UINT16 Offset; // Offset in Variable -// UINT16 DefaultValueOffset; // Offset of the Default Value -// } VARIABLE_HEAD; -// -// typedef struct { -// UINT32 Offset; -// } VPD_HEAD; -// -// typedef UINT16 STRING_HEAD; -// -// typedef UINT16 SIZE_INFO; -// -// #define offsetof(s,m) (UINT32) (UINTN) &(((s *)0)->m) -// -// -// #define PEI_GUID_TABLE_SIZE 1 -// #define PEI_STRING_TABLE_SIZE 1 -// #define PEI_SKUID_TABLE_SIZE 1 -// #define PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE 3 -// #define PEI_LOCAL_TOKEN_NUMBER 3 -// #define PEI_EXMAPPING_TABLE_SIZE 1 -// #define PEI_EX_TOKEN_NUMBER 0 -// #define PEI_SIZE_TABLE_SIZE 2 -// #define PEI_GUID_TABLE_EMPTY TRUE -// #define PEI_STRING_TABLE_EMPTY TRUE -// #define PEI_SKUID_TABLE_EMPTY TRUE -// #define PEI_DATABASE_EMPTY FALSE -// #define PEI_EXMAP_TABLE_EMPTY TRUE -// -// // -// // PEI database structure for dynamic/dynamicex PCD which has default value. -// // -// typedef struct { -// -// -// -// -// -// DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE]; // table for mapping dynamicex token number to local token number -// UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE]; // table for local token number -// GUID GuidTable[PEI_GUID_TABLE_SIZE]; // table for token guid -// -// -// UINT16 StringTable[1]; /* _ */ // table for unicode string type PCD's value -// -// SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE]; // table for PCD size information -// -// -// -// -// -// -// UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE]; // table for SKU IDs -// SKU_ID SystemSkuId; // system SKU ID -// } PEI_PCD_DATABASE_INIT; -// -// // -// // PEI database structure for dynamic/dynamicex PCD which has no default value. -// // -// typedef struct { -// -// -// UINT32 PcdFlashNvStorageVariableBase_a1aff049_fdeb_442a_b320_13ab4cb72bbc[1]; // PCD entry for PcdFlashNvStorageVariableBase -// UINT32 PcdFlashNvStorageFtwSpareBase_a1aff049_fdeb_442a_b320_13ab4cb72bbc[1]; // PCD entry for PcdFlashNvStorageFtwSpareBase -// UINT32 PcdFlashNvStorageFtwWorkingBase_a1aff049_fdeb_442a_b320_13ab4cb72bbc[1]; // PCD entry for PcdFlashNvStorageFtwWorkingBase -// -// -// -// -// } PEI_PCD_DATABASE_UNINIT; -// -// #define PCD_PEI_SERVICE_DRIVER_VERSION 2 -// -// typedef struct { -// PEI_PCD_DATABASE_INIT Init; -// PEI_PCD_DATABASE_UNINIT Uninit; -// } PEI_PCD_DATABASE; -// -// #define PEI_NEX_TOKEN_NUMBER (PEI_LOCAL_TOKEN_NUMBER - PEI_EX_TOKEN_NUMBER) -// -// #define DXE_GUID_TABLE_SIZE 1 -// #define DXE_STRING_TABLE_SIZE 212 -// #define DXE_SKUID_TABLE_SIZE 1 -// #define DXE_LOCAL_TOKEN_NUMBER_TABLE_SIZE 9 -// #define DXE_LOCAL_TOKEN_NUMBER 9 -// #define DXE_EXMAPPING_TABLE_SIZE 1 -// #define DXE_EX_TOKEN_NUMBER 0 -// #define DXE_SIZE_TABLE_SIZE 16 -// #define DXE_GUID_TABLE_EMPTY TRUE -// #define DXE_STRING_TABLE_EMPTY FALSE -// #define DXE_SKUID_TABLE_EMPTY TRUE -// #define DXE_DATABASE_EMPTY FALSE -// #define DXE_EXMAP_TABLE_EMPTY TRUE -// -// typedef struct { -// -// -// -// -// -// DYNAMICEX_MAPPING ExMapTable[DXE_EXMAPPING_TABLE_SIZE]; -// UINT32 LocalTokenNumberTable[DXE_LOCAL_TOKEN_NUMBER_TABLE_SIZE]; -// GUID GuidTable[DXE_GUID_TABLE_SIZE]; -// STRING_HEAD PcdWinNtMemorySize_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtGop_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtSerialPort_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtVirtualDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtUga_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtPhysicalDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtFileSystem_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// STRING_HEAD PcdWinNtConsole_0d79a645_1d91_40a6_a81f_61e6982b32b4[1]; -// -// -// UINT16 StringTable[6]; /* PcdWinNtMemorySize_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_1[26]; /* PcdWinNtGop_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_2[10]; /* PcdWinNtSerialPort_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_3[13]; /* PcdWinNtVirtualDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_4[26]; /* PcdWinNtUga_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_5[51]; /* PcdWinNtPhysicalDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_6[54]; /* PcdWinNtFileSystem_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// UINT16 StringTable_7[26]; /* PcdWinNtConsole_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// -// SIZE_INFO SizeTable[DXE_SIZE_TABLE_SIZE]; -// UINT16 PcdPlatformBootTimeOutDefault_a1aff049_fdeb_442a_b320_13ab4cb72bbc[1]; -// -// -// -// -// -// -// UINT8 SkuIdTable[DXE_SKUID_TABLE_SIZE]; -// -// } DXE_PCD_DATABASE_INIT; -// -// typedef struct { -// UINT8 dummy; /* PCD_DATABASE_UNINIT is emptry */ -// -// -// -// -// -// } DXE_PCD_DATABASE_UNINIT; -// -// #define PCD_DXE_SERVICE_DRIVER_VERSION 2 -// -// typedef struct { -// DXE_PCD_DATABASE_INIT Init; -// DXE_PCD_DATABASE_UNINIT Uninit; -// } DXE_PCD_DATABASE; -// -// #define DXE_NEX_TOKEN_NUMBER (DXE_LOCAL_TOKEN_NUMBER - DXE_EX_TOKEN_NUMBER) -// -// typedef struct { -// PEI_PCD_DATABASE PeiDb; -// DXE_PCD_DATABASE DxeDb; -// } PCD_DATABASE; -// -// #define PCD_TOTAL_TOKEN_NUMBER (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER) -// -// -// DXE_PCD_DATABASE_INIT gDXEPcdDbInit = { -// -// -// -// -// /* VPD */ -// -// /* ExMapTable */ -// { -// { 0, 0, 0 }, -// -// }, -// /* LocalTokenNumberTable */ -// { -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtMemorySize_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtGop_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtSerialPort_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtVirtualDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtUga_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtPhysicalDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtFileSystem_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdWinNtConsole_0d79a645_1d91_40a6_a81f_61e6982b32b4) | PCD_DATUM_TYPE_POINTER | PCD_TYPE_STRING, -// offsetof(DXE_PCD_DATABASE, Init.PcdPlatformBootTimeOutDefault_a1aff049_fdeb_442a_b320_13ab4cb72bbc) | PCD_TYPE_DATA | PCD_DATUM_TYPE_UINT16, -// -// }, -// /* GuidTable */ -// { -// {0x00000000, 0x0000, 0x0000, {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}}, -// -// }, -// { 0 }, /* PcdWinNtMemorySize_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 6 }, /* PcdWinNtGop_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 32 }, /* PcdWinNtSerialPort_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 42 }, /* PcdWinNtVirtualDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 55 }, /* PcdWinNtUga_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 81 }, /* PcdWinNtPhysicalDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 132 }, /* PcdWinNtFileSystem_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// { 186 }, /* PcdWinNtConsole_0d79a645_1d91_40a6_a81f_61e6982b32b4[1] */ -// -// -// /* StringTable */ -// L"64!64", /* PcdWinNtMemorySize_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L"UGA Window 1!UGA Window 2", /* PcdWinNtGop_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L"COM1!COM2", /* PcdWinNtSerialPort_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L"FW;40960;512", /* PcdWinNtVirtualDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L"UGA Window 1!UGA Window 2", /* PcdWinNtUga_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L"a:RW;2880;512!d:RO;307200;2048!j:RW;262144;512", /* PcdWinNtPhysicalDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L".!..\\..\\..\\..\\EdkShellBinPkg\\Bin\\Ia32\\Apps", /* PcdWinNtFileSystem_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// L"Bus Driver Console Window", /* PcdWinNtConsole_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ - -// /* SizeTable */ -// { -// 10, 10, /* PcdWinNtMemorySize_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 50, 50, /* PcdWinNtGop_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 18, 18, /* PcdWinNtSerialPort_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 24, 24, /* PcdWinNtVirtualDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 50, 50, /* PcdWinNtUga_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 100, 92, /* PcdWinNtPhysicalDisk_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 106, 98, /* PcdWinNtFileSystem_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// 50, 50, /* PcdWinNtConsole_0d79a645_1d91_40a6_a81f_61e6982b32b4 */ -// -// }, -// { 10 }, /* PcdPlatformBootTimeOutDefault_a1aff049_fdeb_442a_b320_13ab4cb72bbc[1] */ -// -// -// -// -// -// -// /* SkuIdTable */ -// { 0, }, -// -//}; - +//////////////////////////////////////////////////////////////////////////////// +// // +// Introduction of PCD database // +// // +//////////////////////////////////////////////////////////////////////////////// +/** + 1, Introduction + PEI PCD database hold all dynamic type PCD information used in PEI phase. + The structure of PEI PCD database is generated by build tools according to + dynamic PCD usage for specified platform. + + 2, Dynamic Type PCD + Dynamic type PCD is designed for accessing setting which value is determined + dynamic. In contrast, the value of static type PCD (FeatureFlag, FixedPcd, + PatchablePcd) is fixed in final generated FD image in build time. + + 2.1 The "dynamic" determination means: + a) The PCD value is produced by someone driver and consumed by other driver + in execution time. + b) The PCD value is set/get by user from FrontPage. + c) The PCD value is produced by platform OEM specified area. + + 2.2 According to distribution mehod, dynamic PCD could be classfied as: + a) Dynamic: + This type PCD is used for module in source distribution which will be + built in platform. + b) DynamicEx: + This type PCD is used for module in binary distribution which will be + will not built. + + 2.3 According to storage method, dynamic PCD could be classfied as: + a) Default Storage: + - The value is stored in PCD database maintained by PCD database in boot + time memory which is built as a guid hob in PEI phase. + - This type is used for communication between PEIM/DXE driver, DXE/DXE + driver. But all set/get value will be losted after boot-time memory + is turn off. + - [PcdsDynamicDefault]/[PcdsDynamicExDefault] is used as section name + for this type PCD in platform DSC file. + + b) Variable Storage: + - The value is stored in variable area. + - As default storage type, this type PCD could used for communication. + But beside it, this type PCD could be used store the value associating + with HII setting via variable technology. + - In PEI phase, the PCD value could only be got but can not be set due + to variable area is readonly for PEI phase. + - [PcdsDynamicHii]/[PcdsDynamicExHii] is used as section name for this + type PCD in platform DSC file. + + c) OEM specificed storage area: + - The value is stored in OEM specified area, the base address is specified + by a FixedAtBuild PCD PcdVpdBaseAddress. + - The area is read only for PEI and DXE phase. + - [PcdsDynamicVpd]/[PcdsDynamicExVpd] is used as section name for this + type PCD in platform DSC file. + + Note: The default value of dynamic PCD are storaged in memory maintained + by PEI/DXE PCD drvier. + + 2.4 When and how to use dynamic PCD + Module developer do not care the used PCD is dynamic or static when writting + source code/INF. Dynamic PCD and dynamic type is pointed by platform integrator + in platform DSC file. Please ref section 2.3 to get matching between dynamic + PCD type and section name in DSC file. + + 3, PCD database: + Although dynamic PCD could be in different storage type as above description, + but the basic information and default value for all dynamic PCD is hold + by PCD database maintained by PEI/DXE driver. + + As whole EFI BIOS boot path is divided into PEI/DXE phase, the PCD database + also is divided into Pei/Dxe database maintaied by PcdPeim/PcdDxe driver separatly. + To make PcdPeim's driver image smaller, PEI PCD database only hold all dynamic + PCD information used in PEI phase or use in both PEI/DXE phase. And DXE PCD + database contains all PCDs used in PEI/DXE phase in memory. + + Build tool will generate PCD database into some C structure and variable for + PEI/DXE PCD driver according to dynamic PCD section in platform DSC file. + + 3.1 PcdPeim and PcdDxe + PEI PCD database is maintained by PcdPeim driver run from flash. PcdPeim driver + build guid hob in temporary memory and copy auto-generated C structure + to temporary memory for PEI PCD database. + DXE PCD database is maintained by PcdDxe driver.At entry point of PcdDxe driver, + a new PCD database is allocated in boot-time memory which including all + PEI PCD and DXE PCD entry. + + Pcd driver should run as early as possible before any other driver access + dynamic PCD's value. PEI/DXE "Apriori File" mechanism make it possible by + making PcdPeim/PcdDxe as first dispatching driver in PEI/DXE phase. + + 3.2 Token space Guid/Token number, Platform token, Local token number + Dynamic PCD + +-----------+ +---------+ + |TokenSpace | |Platform | + | Guid | build tool | Token | + | + +-------------->| Number | + | Token | +---------+`._ + | Number | `. + +-----------+ `. +------+ + `-|Local | + |Token | + DynamicEx PCD ,-|Number| + +-----------+ ,-' +------+ + |TokenSpace | ,-' + | Guid | _,-' + | + +.' + | Token | + | Number | + +-----------+ + + + 3.2.1 Pair of Token space guid + Token number + Any type PCD is identified by pair of "TokenSpaceGuid + TokeNumber". But it + is not easy maintained by PCD driver, and hashed token number will make + searching slowly. + + 3.2.2 Platform Token Number + "Platform token number" concept is introduced for mapping to a pair of + "TokenSpaceGuid + TokenNumber". The platform token number is generated by + build tool in autogen.h and all of them are continual in a platform scope + started from 1.(0 meaning invalid internal token number) + With auto-generated "platform token number", PcdGet(PcdSampleDynamicPcd) + in source code is translated to LibPcdGet(_PCD_TOKEN_PcdSampleDynamicPcd) + in autogen.h. + Notes: The mapping between pair of "tokenspace guid + token number" and + "internal token number" need build tool establish, so "platform token number" + mechanism is not suitable for binary module which use DynamicEx type PCD. + To access a dynamicEx type PCD, pair of "token space guid/token number" all need + to be specificed for PcdSet/PcdGet accessing macro. + + Platform Token Number is started from 1, and inceased continuous. From whole + platform scope, there are two zones: PEI Zone and DXE Zone + | Platform Token Number + ----------|---------------------------------------------------------------- + PEI Zone: | 1 ~ PEI_LOCAL_TOKEN_NUMBER + DXE Zone: | (PEI_LOCAL_TOKEN_NUMBER + 1) ~ (PEI_LOCAL_TOKEN_NUMBER + DXE_LOCAL_TOKEN_NUMBER) + + 3.2.3 Local Token Number + To fast searching a PCD entry in PCD database, PCD driver translate + platform token number to local token number via a mapping table. + For binary DynamicEx type PCD, there is a another mapping table to translate + "token space guid + token number" to local token number directly. + Local token number is identifier for all internal interface in PCD PEI/DXE + driver. + + A local token number is a 32-bit value in following meaning: + 32 ------------- 28 ---------- 24 -------- 0 + | PCD type mask | Datum Type | Offset | + +-----------------------------------------+ + where: + PCd type mask: indicate Pcd type from following macro: + PCD_TYPE_DATA + PCD_TYPE_HII + PCD_TYPE_VPD + PCD_TYPE_SKU_ENABLED + PCD_TYPE_STRING + Datum Type : indicate PCD vaue type from following macro: + PCD_DATUM_TYPE_POINTER + PCD_DATUM_TYPE_UINT8 + PCD_DATUM_TYPE_UINT16 + PCD_DATUM_TYPE_UINT32 + PCD_DATUM_TYPE_UINT64 + Offset : indicate the related offset of PCD value in PCD database array. + Based on local token number, PCD driver could fast determine PCD type, value + type and get PCD entry from PCD database. + + 3.3 PCD Database C structure. + PCD Database C structure is generated by build tools in PCD driver's autogen.h/ + autogen.c file. In generated C structure, following information is stored: + - ExMapTable: This table is used translate a binary dynamicex type PCD's + "tokenguid + token" to local token number. + - LocalTokenNumberTable: + This table stores all local token number in array, use "Internal + token number" as array index to get PCD entry's offset fastly. + - SizeTable: This table stores the size information for all PCD entry. + - GuidTable: This table stores guid value for DynamicEx's token space, + HII type PCD's variable. + - SkuIdTable: TBD + - SystemSkuId: TBD + - PCD value structure: + Every PCD has a value record in PCD database. For different + datum type PCD has different record structure which will be + introduced in 3.3.1 + + In a PCD database structure, there are two major area: Init and UnInit. + Init area is use stored above PCD internal structure such as ExMapTable, + LocalTokenNumberTable etc and the (default) value of PCD which has default + value specified in platform DSC file. + Unint area is used stored the value of PCD which has no default value in + platform DSC file, the value of NULL, 0 specified in platform DSC file can + be seemed as "no default value". + + 3.3.1 Simple Sample PCD Database C Structure + A general sample of PCD database structue is as follows: + typedef struct _PCD_DATABASE { + typedef struct _PCD_DATABASE_INIT { + //===== Following is PCD database internal maintain structures + DYNAMICEX_MAPPING ExMapTable[PEI_EXMAPPING_TABLE_SIZE]; + UINT32 LocalTokenNumberTable[PEI_LOCAL_TOKEN_NUMBER_TABLE_SIZE]; + GUID GuidTable[PEI_GUID_TABLE_SIZE]; + SIZE_INFO SizeTable[PEI_SIZE_TABLE_SIZE]; + UINT8 SkuIdTable[PEI_SKUID_TABLE_SIZE]; + SKU_ID SystemSkuId; + + //===== Following is value structure for PCD with default value + .... + .... + .... + } Init; + typedef struct _PCD_DATABSE_UNINIT { + //==== Following is value structure for PCD without default value + .... + .... + } UnInit; + } + + 3.3.2 PCD value structure in PCD database C structure + The value's structure is generated by build tool in PCD database C structure. + The PCDs in different datum type has different value structure. + + 3.3.2.1 UINT8/UINT16/UINT32/UINT64 datum type PCD + The C structure for these datum type PCD is just a UINT8/UINT16/UINT32/UINT64 + data member in PCD database, For example: + UINT16 PcdHardwareErrorRecordLevel_d3705011_bc19_4af7_be16_f68030378c15_VariableDefault_0; + Above structure is generated by build tool, the member name is "PcdCName_Guidvalue" + Member type is UINT16 according to PcdHardwareErrorRecordLevel declaration + in DEC file. + + 3.3.2.2 VOID* datum type PCD + The value of VOID* datum type PCD is a UINT8/UINT16 array in PCD database. + + 3.3.2.2.1 VOID* - string type + If the default value for VOID* datum type PCD like L"xxx", the PCD is + used for unicode string, and C structure of this datum type PCD is + UINT16 string array in PCD database, for example: + UINT16 StringTable[29]; + The number of 29 in above sample is max size of a unicode string. + + If the default value for VOID* datum type PCD like "xxx", the PCD is + used for ascii string, and C structure of this datum type PCD is + UINT8 string array in PCD database, for example: + UINT8 StringTable[20]; + The number of 20 in above sample is max size of a ascii string. + + 3.3.2.2.2 VOID* - byte array + If the default value of VOID* datum type PCD like {'0x29', '0x01', '0xf2'} + the PCD is used for byte array. The generated structrue is same as + above ascii string table, + UINT8 StringTable[13]; + The number of 13 in above sample is max size of byte array. + + 3.3.3 Some utility structures in PCD Database + 3.3.3.1 GuidTable + GuidTable array is used to store all related GUID value in PCD database: + - Variable GUID for HII type PCD + - Token space GUID for dynamicex type PCD + + 3.4 PEI PCD Database + +**/