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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
This commit is contained in:
klu2 2009-03-29 11:20:12 +00:00
parent a5eca427cb
commit cf84d2671a
1 changed files with 261 additions and 295 deletions
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556
MdeModulePkg/Universal/PCD/Dxe/Service.h
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@ -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
**/