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diff --git a/Platform/BroxtonPlatformPkg/Common/SampleCode/MdeModulePkg/Universal/PCD/Pei/PcdPeim.uni b/Platform/BroxtonPlatformPkg/Common/SampleCode/MdeModulePkg/Universal/PCD/Pei/PcdPeim.uni new file mode 100644 index 0000000000..3e7c5566f0 --- /dev/null +++ b/Platform/BroxtonPlatformPkg/Common/SampleCode/MdeModulePkg/Universal/PCD/Pei/PcdPeim.uni @@ -0,0 +1,295 @@ +// /** @file
+// PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service.
+//
+// This version PCD PEIM depends on the external PCD database binary file, not built in PCD data base.
+// There are two PCD PPIs as follows:
+// 1) PCD_PPI
+// It is EDKII implementation which support Dynamic/DynamicEx Pcds.
+// 2) EFI_PEI_PCD_PPI
+// It is defined by PI specification 1.2, Vol 3 which only support dynamicEx
+// type Pcd.
+// For dynamicEx type PCD, it is compatible between PCD_PPI and EFI_PEI_PCD_PPI.
+// PCD PEIM driver will produce above two PPIs at same time.
+//
+// PCD database is generated as the separate binary image at build time. The binary image
+// will be intergrated into Firmware volume together with PCD driver.
+//
+// ////////////////////////////////////////////////////////////////////////////////
+// // //
+// // Introduction of PCD database //
+// // //
+// ////////////////////////////////////////////////////////////////////////////////
+//
+// 1, Introduction
+// PCD database hold all dynamic type PCD information. 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 used for the configuration/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 one of below cases:
+// a) The PCD setting value is produced by someone driver and consumed by
+// other driver in execution time.
+// b) The PCD setting value is set/get by user from FrontPage.
+// c) The PCD setting value is produced by platform OEM vendor in specified area.
+//
+// 2.2 According to module distribution way, dynamic PCD could be classfied as:
+// a) Dynamic:
+// If module is released in source code and will be built with platform
+// DSC, the dynamic PCD used by this module can be accessed as:
+// PcdGetxx(PcdSampleDynamicPcd);
+// In building platform, build tools will translate PcdSampleDynamicPcd to
+// pair of {Token Space Guid: Token Number} for this PCD.
+// b) DynamicEx:
+// If module is release as binary and will not pariticpate platform building,
+// the dynamic PCD used by this module need be accessed as:
+// PcdGetxxEx(gEfiMyTokenspaceGuid, PcdSampleDynamicPcd)
+// Developer need explicity gives {Token Space Guid:Token Number} as parameter
+// in writting source code.
+//
+// 2.3 According to PCD value's storage method, dynamic PCD could be classfied as:
+// a) Default Storage:
+// - The PCD value is stored in PCD database maintained by PCD driver in boot
+// time memory.
+// - 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] is used as section name for this type PCD in
+// platform DSC file. [PcdsDynamicExDefault] is used for dynamicEx type PCD.
+//
+// b) Variable Storage:
+// - The PCD value is stored in variable area.
+// - As default storage type, this type PCD could be used for PEI/DXE driver
+// communication. But beside it, this type PCD could also be used to store
+// the value associate with a HII setting via variable interface.
+// - In PEI phase, the PCD value could only be got but can not be set due
+// to variable area is readonly.
+// - [PcdsDynamicHii] is used as section name for this type PCD in platform
+// DSC file. [PcdsDynamicExHii] is for dynamicEx type PCD.
+//
+// c) OEM specificed storage area:
+// - The PCD value is stored in OEM specified area which base address is
+// specified by a FixedAtBuild PCD setting - PcdVpdBaseAddress.
+// - The area is read only for PEI and DXE phase.
+// - [PcdsDynamicVpd] is used as section name for this type PCD in platform
+// DSC file. [PcdsDynamicExVpd] is for dynamicex type PCD.
+//
+// 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 the 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 the separate binary file 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 the binary data base from flash
+// 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_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 binary file
+// PCD Database binary file will be created at build time as the standalone binary image.
+// To understand the binary image layout, PCD Database C structure is still generated
+// as comments 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 GUID.
+// - 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
+//
+// Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+//
+// This program and the accompanying materials
+// are licensed and made available under the terms and conditions of the BSD License
+// which accompanies this distribution. The full text of the license may be found at
+// http://opensource.org/licenses/bsd-license.php
+// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT #language en-US "PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service."
+
+#string STR_MODULE_DESCRIPTION #language en-US "PCD PEIM produces PCD database to manage all dynamic PCD in PEI phase and install Pcd Ppi service."
+
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