HOB

数据结构, 线性表, 接口, 实现
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HOB简介

基本概念

HOB是Hand-Off Block的缩写。是PEI阶段向DXE传递系统信息的手段。PEI阶段构建一些HOB结构，然后将其作为参数传给DXE阶段函数，DXE Core会根据其使用平台相关资源。

HOB是系列的连续的内存结构体，可以认为其由三部分构成：第一部分，是PHIT头，它描述了HOB的起始地址以及总的内存使用；第二部分是各个Hob列表，DXE阶段会根据这一部分获取相关资源；第三部分是结束部分。

HOB List

相关Spec

  • PI Spec(卷一 4.4 HOB Services小节，规范HOB PeiService相关的方法,Pi卷三4/5章节)
  • EFI Spec（规范HOB的数据结构）

HOB的数据结构表征(PiHob.h)

EFI_HOB_GENERIC_HEADER

描述HOB内部数据的格式和大小,所有HOB都必须包含此通用HOB标头,以便可以找到下一个HOB

///
/// Describes the format and size of the data inside the HOB.
/// All HOBs must contain this generic HOB header.
///
typedef struct {
  ///
  /// Identifies the HOB data structure type.
  ///
  UINT16    HobType;
  ///
  /// The length in bytes of the HOB.
  ///
  UINT16    HobLength;
  ///
  /// This field must always be set to zero.
  ///
  UINT32    Reserved;
} EFI_HOB_GENERIC_HEADER;

HobType

//
// HobType of EFI_HOB_GENERIC_HEADER.
//
#define EFI_HOB_TYPE_HANDOFF              0x0001
#define EFI_HOB_TYPE_MEMORY_ALLOCATION    0x0002
#define EFI_HOB_TYPE_RESOURCE_DESCRIPTOR  0x0003
#define EFI_HOB_TYPE_GUID_EXTENSION       0x0004
#define EFI_HOB_TYPE_FV                   0x0005
#define EFI_HOB_TYPE_CPU                  0x0006
#define EFI_HOB_TYPE_MEMORY_POOL          0x0007
#define EFI_HOB_TYPE_FV2                  0x0009
#define EFI_HOB_TYPE_LOAD_PEIM_UNUSED     0x000A
#define EFI_HOB_TYPE_UEFI_CAPSULE         0x000B
#define EFI_HOB_TYPE_FV3                  0x000C
#define EFI_HOB_TYPE_UNUSED               0xFFFE
#define EFI_HOB_TYPE_END_OF_HOB_LIST      0xFFFF

PHIT HOB

///
/// Contains general state information used by the HOB producer phase.
/// This HOB must be the first one in the HOB list.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_HANDOFF.
  ///
  EFI_HOB_GENERIC_HEADER  Header;
  ///
  /// The version number pertaining to the PHIT HOB definition.
  /// This value is four bytes in length to provide an 8-byte aligned entry
  /// when it is combined with the 4-byte BootMode.
  ///
  UINT32                  Version;
  ///
  /// The system boot mode as determined during the HOB producer phase.
  ///
  EFI_BOOT_MODE           BootMode;
  ///
  /// The highest address location of memory that is allocated for use by the HOB producer
  /// phase. This address must be 4-KB aligned to meet page restrictions of UEFI.
  ///
  EFI_PHYSICAL_ADDRESS    EfiMemoryTop;
  ///
  /// The lowest address location of memory that is allocated for use by the HOB producer phase.
  ///
  EFI_PHYSICAL_ADDRESS    EfiMemoryBottom;
  ///
  /// The highest address location of free memory that is currently available
  /// for use by the HOB producer phase.
  ///
  EFI_PHYSICAL_ADDRESS    EfiFreeMemoryTop;
  ///
  /// The lowest address location of free memory that is available for use by the HOB producer phase.
  ///
  EFI_PHYSICAL_ADDRESS    EfiFreeMemoryBottom;
  ///
  /// The end of the HOB list.
  ///
  EFI_PHYSICAL_ADDRESS    EfiEndOfHobList;
} EFI_HOB_HANDOFF_INFO_TABLE;

EFI_HOB_MEMORY_ALLOCATION_HEADER


///
/// EFI_HOB_MEMORY_ALLOCATION_HEADER describes the
/// various attributes of the logical memory allocation. The type field will be used for
/// subsequent inclusion in the UEFI memory map.
///
typedef struct {
  ///
  /// A GUID that defines the memory allocation region's type and purpose, as well as
  /// other fields within the memory allocation HOB. This GUID is used to define the
  /// additional data within the HOB that may be present for the memory allocation HOB.
  /// Type EFI_GUID is defined in InstallProtocolInterface() in the UEFI 2.0
  /// specification.
  ///
  EFI_GUID              Name;

  ///
  /// The base address of memory allocated by this HOB. Type
  /// EFI_PHYSICAL_ADDRESS is defined in AllocatePages() in the UEFI 2.0
  /// specification.
  ///
  EFI_PHYSICAL_ADDRESS  MemoryBaseAddress;

  ///
  /// The length in bytes of memory allocated by this HOB.
  ///
  UINT64                MemoryLength;

  ///
  /// Defines the type of memory allocated by this HOB. The memory type definition
  /// follows the EFI_MEMORY_TYPE definition. Type EFI_MEMORY_TYPE is defined
  /// in AllocatePages() in the UEFI 2.0 specification.
  ///
  EFI_MEMORY_TYPE       MemoryType;

  ///
  /// Padding for Itanium processor family
  ///
  UINT8                 Reserved[4];
} EFI_HOB_MEMORY_ALLOCATION_HEADER;

EFI_HOB_MEMORY_ALLOCATION

///
/// Describes all memory ranges used during the HOB producer
/// phase that exist outside the HOB list. This HOB type
/// describes how memory is used, not the physical attributes of memory.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_MEMORY_ALLOCATION.
  ///
  EFI_HOB_GENERIC_HEADER            Header;
  ///
  /// An instance of the EFI_HOB_MEMORY_ALLOCATION_HEADER that describes the
  /// various attributes of the logical memory allocation.
  ///
  EFI_HOB_MEMORY_ALLOCATION_HEADER  AllocDescriptor;
  //
  // Additional data pertaining to the "Name" Guid memory
  // may go here.
  //
} EFI_HOB_MEMORY_ALLOCATION;

EFI_HOB_MEMORY_ALLOCATION_STACK

///
/// Describes the memory stack that is produced by the HOB producer
/// phase and upon which all post-memory-installed executable
/// content in the HOB producer phase is executing.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_MEMORY_ALLOCATION.
  ///
  EFI_HOB_GENERIC_HEADER            Header;
  ///
  /// An instance of the EFI_HOB_MEMORY_ALLOCATION_HEADER that describes the
  /// various attributes of the logical memory allocation.
  ///
  EFI_HOB_MEMORY_ALLOCATION_HEADER  AllocDescriptor;
} EFI_HOB_MEMORY_ALLOCATION_STACK;

EFI_HOB_MEMORY_ALLOCATION_BSP_STORE

///
/// Defines the location of the boot-strap
/// processor (BSP) BSPStore ("Backing Store Pointer Store").
/// This HOB is valid for the Itanium processor family only
/// register overflow store.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_MEMORY_ALLOCATION.
  ///
  EFI_HOB_GENERIC_HEADER            Header;
  ///
  /// An instance of the EFI_HOB_MEMORY_ALLOCATION_HEADER that describes the
  /// various attributes of the logical memory allocation.
  ///
  EFI_HOB_MEMORY_ALLOCATION_HEADER  AllocDescriptor;
} EFI_HOB_MEMORY_ALLOCATION_BSP_STORE;

EFI_HOB_MEMORY_ALLOCATION_MODULE

///
/// Defines the location and entry point of the HOB consumer phase.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_MEMORY_ALLOCATION.
  ///
  EFI_HOB_GENERIC_HEADER            Header;
  ///
  /// An instance of the EFI_HOB_MEMORY_ALLOCATION_HEADER that describes the
  /// various attributes of the logical memory allocation.
  ///
  EFI_HOB_MEMORY_ALLOCATION_HEADER  MemoryAllocationHeader;
  ///
  /// The GUID specifying the values of the firmware file system name
  /// that contains the HOB consumer phase component.
  ///
  EFI_GUID                          ModuleName;
  ///
  /// The address of the memory-mapped firmware volume
  /// that contains the HOB consumer phase firmware file.
  ///
  EFI_PHYSICAL_ADDRESS              EntryPoint;
} EFI_HOB_MEMORY_ALLOCATION_MODULE;

EFI_HOB_RESOURCE_DESCRIPTOR

///
/// Describes the resource properties of all fixed,
/// nonrelocatable resource ranges found on the processor
/// host bus during the HOB producer phase.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_RESOURCE_DESCRIPTOR.
  ///
  EFI_HOB_GENERIC_HEADER      Header;
  ///
  /// A GUID representing the owner of the resource. This GUID is used by HOB
  /// consumer phase components to correlate device ownership of a resource.
  ///
  EFI_GUID                    Owner;
  ///
  /// The resource type enumeration as defined by EFI_RESOURCE_TYPE.
  ///
  EFI_RESOURCE_TYPE           ResourceType;
  ///
  /// Resource attributes as defined by EFI_RESOURCE_ATTRIBUTE_TYPE.
  ///
  EFI_RESOURCE_ATTRIBUTE_TYPE ResourceAttribute;
  ///
  /// The physical start address of the resource region.
  ///
  EFI_PHYSICAL_ADDRESS        PhysicalStart;
  ///
  /// The number of bytes of the resource region.
  ///
  UINT64                      ResourceLength;
} EFI_HOB_RESOURCE_DESCRIPTOR;

EFI_HOB_GUID_TYPE

///
/// Allows writers of executable content in the HOB producer phase to
/// maintain and manage HOBs with specific GUID.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_GUID_EXTENSION.
  ///
  EFI_HOB_GENERIC_HEADER      Header;
  ///
  /// A GUID that defines the contents of this HOB.
  ///
  EFI_GUID                    Name;
  //
  // Guid specific data goes here
  //
} EFI_HOB_GUID_TYPE;

EFI_HOB_FIRMWARE_VOLUME

///
/// Details the location of firmware volumes that contain firmware files.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_FV.
  ///
  EFI_HOB_GENERIC_HEADER Header;
  ///
  /// The physical memory-mapped base address of the firmware volume.
  ///
  EFI_PHYSICAL_ADDRESS   BaseAddress;
  ///
  /// The length in bytes of the firmware volume.
  ///
  UINT64                 Length;
} EFI_HOB_FIRMWARE_VOLUME;

EFI_HOB_FIRMWARE_VOLUME2

///
/// Details the location of a firmware volume that was extracted
/// from a file within another firmware volume.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_FV2.
  ///
  EFI_HOB_GENERIC_HEADER  Header;
  ///
  /// The physical memory-mapped base address of the firmware volume.
  ///
  EFI_PHYSICAL_ADDRESS    BaseAddress;
  ///
  /// The length in bytes of the firmware volume.
  ///
  UINT64                  Length;
  ///
  /// The name of the firmware volume.
  ///
  EFI_GUID                FvName;
  ///
  /// The name of the firmware file that contained this firmware volume.
  ///
  EFI_GUID                FileName;
} EFI_HOB_FIRMWARE_VOLUME2;

EFI_HOB_FIRMWARE_VOLUME3

///
/// Details the location of a firmware volume that was extracted
/// from a file within another firmware volume.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_FV3.
  ///
  EFI_HOB_GENERIC_HEADER  Header;
  ///
  /// The physical memory-mapped base address of the firmware volume.
  ///
  EFI_PHYSICAL_ADDRESS    BaseAddress;
  ///
  /// The length in bytes of the firmware volume.
  ///
  UINT64                  Length;
  ///
  /// The authentication status.
  ///
  UINT32                  AuthenticationStatus;
  ///
  /// TRUE if the FV was extracted as a file within another firmware volume.
  /// FALSE otherwise.
  ///
  BOOLEAN                 ExtractedFv;
  ///
  /// The name of the firmware volume.
  /// Valid only if IsExtractedFv is TRUE.
  ///
  EFI_GUID                FvName;
  ///
  /// The name of the firmware file that contained this firmware volume.
  /// Valid only if IsExtractedFv is TRUE.
  ///
  EFI_GUID                FileName;
} EFI_HOB_FIRMWARE_VOLUME3;

EFI_HOB_CPU

///
/// Describes processor information, such as address space and I/O space capabilities.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_CPU.
  ///
  EFI_HOB_GENERIC_HEADER  Header;
  ///
  /// Identifies the maximum physical memory addressability of the processor.
  ///
  UINT8                   SizeOfMemorySpace;
  ///
  /// Identifies the maximum physical I/O addressability of the processor.
  ///
  UINT8                   SizeOfIoSpace;
  ///
  /// This field will always be set to zero.
  ///
  UINT8                   Reserved[6];
} EFI_HOB_CPU;

EFI_HOB_MEMORY_POOL

///
/// Describes pool memory allocations.
///
typedef struct {
  ///
  /// The HOB generic header. Header.HobType = EFI_HOB_TYPE_MEMORY_POOL.
  ///
  EFI_HOB_GENERIC_HEADER  Header;
} EFI_HOB_MEMORY_POOL;

EFI_HOB_UEFI_CAPSULE

/// Each UEFI capsule HOB details the location of a UEFI capsule. It includes a base address and length
/// which is based upon memory blocks with a EFI_CAPSULE_HEADER and the associated
/// CapsuleImageSize-based payloads. These HOB's shall be created by the PEI PI firmware
/// sometime after the UEFI UpdateCapsule service invocation with the
/// CAPSULE_FLAGS_POPULATE_SYSTEM_TABLE flag set in the EFI_CAPSULE_HEADER.
///
typedef struct {
  ///
  /// The HOB generic header where Header.HobType = EFI_HOB_TYPE_UEFI_CAPSULE.
  ///
  EFI_HOB_GENERIC_HEADER Header;

  ///
  /// The physical memory-mapped base address of an UEFI capsule. This value is set to
  /// point to the base of the contiguous memory of the UEFI capsule.
  /// The length of the contiguous memory in bytes.
  ///
  EFI_PHYSICAL_ADDRESS   BaseAddress;
  UINT64                 Length;
} EFI_HOB_UEFI_CAPSULE;

EFI_PEI_HOB_POINTERS

使用union最大的好处是提高源码的可读性和间接性。利用该类型中所有域的取值均一样的特点，在不同的使用方法下，可以使用不同的变量名字，一方面可以省去强制类型转换的麻烦，另一方面可以直接体现出当前的使用需求。

///
/// Union of all the possible HOB Types.
///
typedef union {
  EFI_HOB_GENERIC_HEADER              *Header;
  EFI_HOB_HANDOFF_INFO_TABLE          *HandoffInformationTable;
  EFI_HOB_MEMORY_ALLOCATION           *MemoryAllocation;
  EFI_HOB_MEMORY_ALLOCATION_BSP_STORE *MemoryAllocationBspStore;
  EFI_HOB_MEMORY_ALLOCATION_STACK     *MemoryAllocationStack;
  EFI_HOB_MEMORY_ALLOCATION_MODULE    *MemoryAllocationModule;
  EFI_HOB_RESOURCE_DESCRIPTOR         *ResourceDescriptor;
  EFI_HOB_GUID_TYPE                   *Guid;
  EFI_HOB_FIRMWARE_VOLUME             *FirmwareVolume;
  EFI_HOB_FIRMWARE_VOLUME2            *FirmwareVolume2;
  EFI_HOB_FIRMWARE_VOLUME3            *FirmwareVolume3;
  EFI_HOB_CPU                         *Cpu;
  EFI_HOB_MEMORY_POOL                 *Pool;
  EFI_HOB_UEFI_CAPSULE                *Capsule;
  UINT8                               *Raw;
} EFI_PEI_HOB_POINTERS;

HOB相关方法的声明（HobLib.h）

增

  • BuildModuleHob
  • BuildResourceDescriptorWithOwnerHob
  • BuildResourceDescriptorHob
  • BuildGuidHob
  • BuildGuidDataHob
  • BuildFvHob
  • BuildFv2Hob
  • BuildFv3Hob
  • BuildCvHob
  • BuildCpuHob
  • BuildStackHob
  • BuildBspStoreHob
  • BuildMemoryAllocationHob
/**
  Builds a HOB for a loaded PE32 module.

  This function builds a HOB for a loaded PE32 module.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If ModuleName is NULL, then ASSERT().
  If there is no additional space for HOB creation, then ASSERT().

  @param  ModuleName              The GUID File Name of the module.
  @param  MemoryAllocationModule  The 64 bit physical address of the module.
  @param  ModuleLength            The length of the module in bytes.
  @param  EntryPoint              The 64 bit physical address of the module entry point.

**/
VOID
EFIAPI
BuildModuleHob (
  IN CONST EFI_GUID         *ModuleName,
  IN EFI_PHYSICAL_ADDRESS   MemoryAllocationModule,
  IN UINT64                 ModuleLength,
  IN EFI_PHYSICAL_ADDRESS   EntryPoint
  );

/**
  Builds a HOB that describes a chunk of system memory with Owner GUID.

  This function builds a HOB that describes a chunk of system memory.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().

  @param  ResourceType        The type of resource described by this HOB.
  @param  ResourceAttribute   The resource attributes of the memory described by this HOB.
  @param  PhysicalStart       The 64 bit physical address of memory described by this HOB.
  @param  NumberOfBytes       The length of the memory described by this HOB in bytes.
  @param  OwnerGUID           GUID for the owner of this resource.

**/
VOID
EFIAPI
BuildResourceDescriptorWithOwnerHob (
  IN EFI_RESOURCE_TYPE            ResourceType,
  IN EFI_RESOURCE_ATTRIBUTE_TYPE  ResourceAttribute,
  IN EFI_PHYSICAL_ADDRESS         PhysicalStart,
  IN UINT64                       NumberOfBytes,
  IN EFI_GUID                     *OwnerGUID
  );

/**
  Builds a HOB that describes a chunk of system memory.

  This function builds a HOB that describes a chunk of system memory.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().

  @param  ResourceType        The type of resource described by this HOB.
  @param  ResourceAttribute   The resource attributes of the memory described by this HOB.
  @param  PhysicalStart       The 64 bit physical address of memory described by this HOB.
  @param  NumberOfBytes       The length of the memory described by this HOB in bytes.

**/
VOID
EFIAPI
BuildResourceDescriptorHob (
  IN EFI_RESOURCE_TYPE            ResourceType,
  IN EFI_RESOURCE_ATTRIBUTE_TYPE  ResourceAttribute,
  IN EFI_PHYSICAL_ADDRESS         PhysicalStart,
  IN UINT64                       NumberOfBytes
  );

/**
  Builds a customized HOB tagged with a GUID for identification and returns
  the start address of GUID HOB data.

  This function builds a customized HOB tagged with a GUID for identification
  and returns the start address of GUID HOB data so that caller can fill the customized data.
  The HOB Header and Name field is already stripped.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If Guid is NULL, then ASSERT().
  If there is no additional space for HOB creation, then ASSERT().
  If DataLength > (0xFFF8 - sizeof (EFI_HOB_GUID_TYPE)), then ASSERT().
  HobLength is UINT16 and multiples of 8 bytes, so the max HobLength is 0xFFF8.

  @param  Guid          The GUID to tag the customized HOB.
  @param  DataLength    The size of the data payload for the GUID HOB.

  @retval  NULL         The GUID HOB could not be allocated.
  @retval  others       The start address of GUID HOB data.

**/
VOID *
EFIAPI
BuildGuidHob (
  IN CONST EFI_GUID              *Guid,
  IN UINTN                       DataLength
  );

/**
  Builds a customized HOB tagged with a GUID for identification, copies the input data to the HOB
  data field, and returns the start address of the GUID HOB data.

  This function builds a customized HOB tagged with a GUID for identification and copies the input
  data to the HOB data field and returns the start address of the GUID HOB data.  It can only be
  invoked during PEI phase; for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.
  The HOB Header and Name field is already stripped.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If Guid is NULL, then ASSERT().
  If Data is NULL and DataLength > 0, then ASSERT().
  If there is no additional space for HOB creation, then ASSERT().
  If DataLength > (0xFFF8 - sizeof (EFI_HOB_GUID_TYPE)), then ASSERT().
  HobLength is UINT16 and multiples of 8 bytes, so the max HobLength is 0xFFF8.

  @param  Guid          The GUID to tag the customized HOB.
  @param  Data          The data to be copied into the data field of the GUID HOB.
  @param  DataLength    The size of the data payload for the GUID HOB.

  @retval  NULL         The GUID HOB could not be allocated.
  @retval  others       The start address of GUID HOB data.

**/
VOID *
EFIAPI
BuildGuidDataHob (
  IN CONST EFI_GUID              *Guid,
  IN VOID                        *Data,
  IN UINTN                       DataLength
  );

/**
  Builds a Firmware Volume HOB.

  This function builds a Firmware Volume HOB.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().
  If the FvImage buffer is not at its required alignment, then ASSERT().

  @param  BaseAddress   The base address of the Firmware Volume.
  @param  Length        The size of the Firmware Volume in bytes.

**/
VOID
EFIAPI
BuildFvHob (
  IN EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN UINT64                      Length
  );

/**
  Builds a EFI_HOB_TYPE_FV2 HOB.

  This function builds a EFI_HOB_TYPE_FV2 HOB.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().
  If the FvImage buffer is not at its required alignment, then ASSERT().

  @param  BaseAddress   The base address of the Firmware Volume.
  @param  Length        The size of the Firmware Volume in bytes.
  @param  FvName        The name of the Firmware Volume.
  @param  FileName      The name of the file.

**/
VOID
EFIAPI
BuildFv2Hob (
  IN          EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN          UINT64                      Length,
  IN CONST    EFI_GUID                    *FvName,
  IN CONST    EFI_GUID                    *FileName
  );

/**
  Builds a EFI_HOB_TYPE_FV3 HOB.

  This function builds a EFI_HOB_TYPE_FV3 HOB.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().
  If the FvImage buffer is not at its required alignment, then ASSERT().

  @param BaseAddress            The base address of the Firmware Volume.
  @param Length                 The size of the Firmware Volume in bytes.
  @param AuthenticationStatus   The authentication status.
  @param ExtractedFv            TRUE if the FV was extracted as a file within
                                another firmware volume. FALSE otherwise.
  @param FvName                 The name of the Firmware Volume.
                                Valid only if IsExtractedFv is TRUE.
  @param FileName               The name of the file.
                                Valid only if IsExtractedFv is TRUE.

**/
VOID
EFIAPI
BuildFv3Hob (
  IN          EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN          UINT64                      Length,
  IN          UINT32                      AuthenticationStatus,
  IN          BOOLEAN                     ExtractedFv,
  IN CONST    EFI_GUID                    *FvName, OPTIONAL
  IN CONST    EFI_GUID                    *FileName OPTIONAL
  );

/**
  Builds a Capsule Volume HOB.

  This function builds a Capsule Volume HOB.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If the platform does not support Capsule Volume HOBs, then ASSERT().
  If there is no additional space for HOB creation, then ASSERT().

  @param  BaseAddress   The base address of the Capsule Volume.
  @param  Length        The size of the Capsule Volume in bytes.

**/
VOID
EFIAPI
BuildCvHob (
  IN EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN UINT64                      Length
  );

/**
  Builds a HOB for the CPU.

  This function builds a HOB for the CPU.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().

  @param  SizeOfMemorySpace   The maximum physical memory addressability of the processor.
  @param  SizeOfIoSpace       The maximum physical I/O addressability of the processor.

**/
VOID
EFIAPI
BuildCpuHob (
  IN UINT8                       SizeOfMemorySpace,
  IN UINT8                       SizeOfIoSpace
  );

/**
  Builds a HOB for the Stack.

  This function builds a HOB for the stack.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().

  @param  BaseAddress   The 64 bit physical address of the Stack.
  @param  Length        The length of the stack in bytes.

**/
VOID
EFIAPI
BuildStackHob (
  IN EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN UINT64                      Length
  );

/**
  Builds a HOB for the BSP store.

  This function builds a HOB for BSP store.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().

  @param  BaseAddress   The 64 bit physical address of the BSP.
  @param  Length        The length of the BSP store in bytes.
  @param  MemoryType    Type of memory allocated by this HOB.

**/
VOID
EFIAPI
BuildBspStoreHob (
  IN EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN UINT64                      Length,
  IN EFI_MEMORY_TYPE             MemoryType
  );

/**
  Builds a HOB for the memory allocation.

  This function builds a HOB for the memory allocation.
  It can only be invoked during PEI phase;
  for DXE phase, it will ASSERT() since PEI HOB is read-only for DXE phase.

  If there is no additional space for HOB creation, then ASSERT().

  @param  BaseAddress   The 64 bit physical address of the memory.
  @param  Length        The length of the memory allocation in bytes.
  @param  MemoryType    Type of memory allocated by this HOB.

**/
VOID
EFIAPI
BuildMemoryAllocationHob (
  IN EFI_PHYSICAL_ADDRESS        BaseAddress,
  IN UINT64                      Length,
  IN EFI_MEMORY_TYPE             MemoryType
  );

删

无此方法

查

  • GetHobList
  • GetNextHob
  • GetFirstHob
  • GetFirstGuidHob
  • GetNextGuidHob
  • GetBootModeHob
/**
  Returns the pointer to the HOB list.

  This function returns the pointer to first HOB in the list.
  For PEI phase, the PEI service GetHobList() can be used to retrieve the pointer
  to the HOB list.  For the DXE phase, the HOB list pointer can be retrieved through
  the EFI System Table by looking up theHOB list GUID in the System Configuration Table.
  Since the System Configuration Table does not exist that the time the DXE Core is
  launched, the DXE Core uses a global variable from the DXE Core Entry Point Library
  to manage the pointer to the HOB list.

  If the pointer to the HOB list is NULL, then ASSERT().

  @return The pointer to the HOB list.

**/
VOID *
EFIAPI
GetHobList (
  VOID
  );

/**
  Returns the next instance of a HOB type from the starting HOB.

  This function searches the first instance of a HOB type from the starting HOB pointer.
  If there does not exist such HOB type from the starting HOB pointer, it will return NULL.
  In contrast with macro GET_NEXT_HOB(), this function does not skip the starting HOB pointer
  unconditionally: it returns HobStart back if HobStart itself meets the requirement;
  caller is required to use GET_NEXT_HOB() if it wishes to skip current HobStart.

  If HobStart is NULL, then ASSERT().

  @param  Type          The HOB type to return.
  @param  HobStart      The starting HOB pointer to search from.

  @return The next instance of a HOB type from the starting HOB.

**/
VOID *
EFIAPI
GetNextHob (
  IN UINT16                 Type,
  IN CONST VOID             *HobStart
  );

/**
  Returns the first instance of a HOB type among the whole HOB list.

  This function searches the first instance of a HOB type among the whole HOB list.
  If there does not exist such HOB type in the HOB list, it will return NULL.

  If the pointer to the HOB list is NULL, then ASSERT().

  @param  Type          The HOB type to return.

  @return The next instance of a HOB type from the starting HOB.

**/
VOID *
EFIAPI
GetFirstHob (
  IN UINT16                 Type
  );

/**
  Returns the next instance of the matched GUID HOB from the starting HOB.

  This function searches the first instance of a HOB from the starting HOB pointer.
  Such HOB should satisfy two conditions:
  its HOB type is EFI_HOB_TYPE_GUID_EXTENSION and its GUID Name equals to the input Guid.
  If there does not exist such HOB from the starting HOB pointer, it will return NULL.
  Caller is required to apply GET_GUID_HOB_DATA () and GET_GUID_HOB_DATA_SIZE ()
  to extract the data section and its size info respectively.
  In contrast with macro GET_NEXT_HOB(), this function does not skip the starting HOB pointer
  unconditionally: it returns HobStart back if HobStart itself meets the requirement;
  caller is required to use GET_NEXT_HOB() if it wishes to skip current HobStart.

  If Guid is NULL, then ASSERT().
  If HobStart is NULL, then ASSERT().

  @param  Guid          The GUID to match with in the HOB list.
  @param  HobStart      A pointer to a Guid.

  @return The next instance of the matched GUID HOB from the starting HOB.

**/
VOID *
EFIAPI
GetNextGuidHob (
  IN CONST EFI_GUID         *Guid,
  IN CONST VOID             *HobStart
  );

/**
  Returns the first instance of the matched GUID HOB among the whole HOB list.

  This function searches the first instance of a HOB among the whole HOB list.
  Such HOB should satisfy two conditions:
  its HOB type is EFI_HOB_TYPE_GUID_EXTENSION and its GUID Name equals to the input Guid.
  If there does not exist such HOB from the starting HOB pointer, it will return NULL.
  Caller is required to apply GET_GUID_HOB_DATA () and GET_GUID_HOB_DATA_SIZE ()
  to extract the data section and its size info respectively.

  If the pointer to the HOB list is NULL, then ASSERT().
  If Guid is NULL, then ASSERT().

  @param  Guid          The GUID to match with in the HOB list.

  @return The first instance of the matched GUID HOB among the whole HOB list.

**/
VOID *
EFIAPI
GetFirstGuidHob (
  IN CONST EFI_GUID         *Guid
  );

/**
  Get the system boot mode from the HOB list.

  This function returns the system boot mode information from the
  PHIT HOB in HOB list.

  If the pointer to the HOB list is NULL, then ASSERT().

  @param  VOID

  @return The Boot Mode.

**/
EFI_BOOT_MODE
EFIAPI
GetBootModeHob (
  VOID
  );

改

未提供方法，一般是先找到感兴趣的Hob，再修改Block中的数据

HOB相关接口的实现

  • HobLib.h
  • MdePkg\Library\PeiHobLib\HobLib.c
  • MdePkg\Library\DxeHobLib\HobLib.c
  • MdePkg\Library\DxeCoreHobLib\HobLib.c
  • IntelFrameworkPkg\Library\PeiHobLibFramework\HobLib.c

相关宏函数

  • GET_HOB_TYPE
  • GET_HOB_LENGTH
  • GET_NEXT_HOB
  • END_OF_HOB_LIST
  • GET_GUID_HOB_DATAET_GUID_HOB_DATA
  • GET_GUID_HOB_DATA_SIZE
/**
  Returns the type of a HOB.

  This macro returns the HobType field from the HOB header for the
  HOB specified by HobStart.

  @param  HobStart   A pointer to a HOB.

  @return HobType.

**/
#define GET_HOB_TYPE(HobStart) \
  ((*(EFI_HOB_GENERIC_HEADER **)&(HobStart))->HobType)

/**
  Returns the length, in bytes, of a HOB.

  This macro returns the HobLength field from the HOB header for the
  HOB specified by HobStart.

  @param  HobStart   A pointer to a HOB.

  @return HobLength.

**/
#define GET_HOB_LENGTH(HobStart) \
  ((*(EFI_HOB_GENERIC_HEADER **)&(HobStart))->HobLength)

/**
  Returns a pointer to the next HOB in the HOB list.

  This macro returns a pointer to HOB that follows the
  HOB specified by HobStart in the HOB List.

  @param  HobStart   A pointer to a HOB.

  @return A pointer to the next HOB in the HOB list.

**/
#define GET_NEXT_HOB(HobStart) \
  (VOID *)(*(UINT8 **)&(HobStart) + GET_HOB_LENGTH (HobStart))

/**
  Determines if a HOB is the last HOB in the HOB list.

  This macro determine if the HOB specified by HobStart is the
  last HOB in the HOB list.  If HobStart is last HOB in the HOB list,
  then TRUE is returned.  Otherwise, FALSE is returned.

  @param  HobStart   A pointer to a HOB.

  @retval TRUE       The HOB specified by HobStart is the last HOB in the HOB list.
  @retval FALSE      The HOB specified by HobStart is not the last HOB in the HOB list.

**/
#define END_OF_HOB_LIST(HobStart)  (GET_HOB_TYPE (HobStart) == (UINT16)EFI_HOB_TYPE_END_OF_HOB_LIST)

/**
  Returns a pointer to data buffer from a HOB of type EFI_HOB_TYPE_GUID_EXTENSION.

  This macro returns a pointer to the data buffer in a HOB specified by HobStart.
  HobStart is assumed to be a HOB of type EFI_HOB_TYPE_GUID_EXTENSION.

  @param   GuidHob   A pointer to a HOB.

  @return  A pointer to the data buffer in a HOB.

**/
#define GET_GUID_HOB_DATA(HobStart) \
  (VOID *)(*(UINT8 **)&(HobStart) + sizeof (EFI_HOB_GUID_TYPE))

/**
  Returns the size of the data buffer from a HOB of type EFI_HOB_TYPE_GUID_EXTENSION.

  This macro returns the size, in bytes, of the data buffer in a HOB specified by HobStart.
  HobStart is assumed to be a HOB of type EFI_HOB_TYPE_GUID_EXTENSION.

  @param   GuidHob   A pointer to a HOB.

  @return  The size of the data buffer.
**/
#define GET_GUID_HOB_DATA_SIZE(HobStart) \
  (UINT16)(GET_HOB_LENGTH (HobStart) - sizeof (EFI_HOB_GUID_TYPE))

CreateHob(仅PEI阶段有效)

  • MdeModulePkg\Core\Pei\PeiMain.h
/**
  Add a new HOB to the HOB List.
 
  @param PeiServices        An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation.
  @param Type               Type of the new HOB.
  @param Length             Length of the new HOB to allocate.
  @param Hob                Pointer to the new HOB.
 
  @return  EFI_SUCCESS           Success to create hob.
  @retval  EFI_INVALID_PARAMETER if Hob is NULL
  @retval  EFI_NOT_AVAILABLE_YET if HobList is still not available.
  @retval  EFI_OUT_OF_RESOURCES  if there is no more memory to grow the Hoblist.
 
**/
EFI_STATUS
EFIAPI
PeiCreateHob (
  IN CONST EFI_PEI_SERVICES  **PeiServices,
  IN UINT16            Type,
  IN UINT16            Length,
  IN OUT VOID          **Hob
  );
  • MdeModulePkg\Core\Pei\Hob\Hob.c
/**
  Add a new HOB to the HOB List.
 
  @param PeiServices      An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation.
  @param Type             Type of the new HOB.
  @param Length           Length of the new HOB to allocate.
  @param Hob              Pointer to the new HOB.
 
  @return  EFI_SUCCESS           Success to create hob.
  @retval  EFI_INVALID_PARAMETER if Hob is NULL
  @retval  EFI_NOT_AVAILABLE_YET if HobList is still not available.
  @retval  EFI_OUT_OF_RESOURCES  if there is no more memory to grow the Hoblist.
 
**/
EFI_STATUS
EFIAPI
PeiCreateHob (
  IN CONST EFI_PEI_SERVICES  **PeiServices,
  IN UINT16            Type,
  IN UINT16            Length,
  IN OUT VOID          **Hob
  )
{
  EFI_STATUS                           Status;
  EFI_HOB_HANDOFF_INFO_TABLE           *HandOffHob;
  EFI_HOB_GENERIC_HEADER               *HobEnd;
  EFI_PHYSICAL_ADDRESS                 FreeMemory;
 
 
  Status = PeiGetHobList (PeiServices, Hob);
  if (EFI_ERROR(Status)) {
    return Status;
  }
 
  HandOffHob = *Hob;
 
  //
  // Check Length to avoid data overflow.
  //
  if (0x10000 - Length <= 0x7) {
    return EFI_INVALID_PARAMETER;
  }
  Length     = (UINT16)((Length + 0x7) & (~0x7));
 
  FreeMemory = HandOffHob->EfiFreeMemoryTop -
               HandOffHob->EfiFreeMemoryBottom;
 
  if (FreeMemory < Length) {
    DEBUG ((EFI_D_ERROR, "PeiCreateHob fail: Length - 0x%08x\n", (UINTN)Length));
    DEBUG ((EFI_D_ERROR, "  FreeMemoryTop    - 0x%08x\n", (UINTN)HandOffHob->EfiFreeMemoryTop));
    DEBUG ((EFI_D_ERROR, "  FreeMemoryBottom - 0x%08x\n", (UINTN)HandOffHob->EfiFreeMemoryBottom));
    return EFI_OUT_OF_RESOURCES;
  }
 
  *Hob = (VOID*) (UINTN) HandOffHob->EfiEndOfHobList;
  ((EFI_HOB_GENERIC_HEADER*) *Hob)->HobType   = Type;
  ((EFI_HOB_GENERIC_HEADER*) *Hob)->HobLength = Length;
  ((EFI_HOB_GENERIC_HEADER*) *Hob)->Reserved  = 0;
 
  HobEnd = (EFI_HOB_GENERIC_HEADER*) ((UINTN) *Hob + Length);
  HandOffHob->EfiEndOfHobList = (EFI_PHYSICAL_ADDRESS) (UINTN) HobEnd;
 
  HobEnd->HobType   = EFI_HOB_TYPE_END_OF_HOB_LIST;
  HobEnd->HobLength = (UINT16) sizeof (EFI_HOB_GENERIC_HEADER);
  HobEnd->Reserved  = 0;
  HobEnd++;
  HandOffHob->EfiFreeMemoryBottom = (EFI_PHYSICAL_ADDRESS) (UINTN) HobEnd;
 
  return EFI_SUCCESS;
}
  • MdePkg\Include\Pi\PiPeiCis.h
/**
  This service, published by the PEI Foundation, abstracts the creation of a Hand-Off Block's (HOB's) headers.
 
  @param  PeiServices      An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation.
  @param  Type             The type of HOB to be installed.
  @param  Length           The length of the HOB to be added.
  @param  Hob              The address of a pointer that will contain the HOB header.
 
  @retval EFI_SUCCESS           The HOB was successfully created.
  @retval EFI_OUT_OF_RESOURCES  There is no additional space for HOB creation.
 
**/
typedef
EFI_STATUS
(EFIAPI *EFI_PEI_CREATE_HOB)(
  IN CONST EFI_PEI_SERVICES            **PeiServices,
  IN UINT16                            Type,
  IN UINT16                            Length,
  IN OUT VOID                          **Hob
  );
 

/// EFI_PEI_SERVICES is a collection of functions whose implementation is provided by the PEI
/// Foundation. These services fall into various classes, including the following:
/// - Managing the boot mode
/// - Allocating both early and permanent memory
/// - Supporting the Firmware File System (FFS)
/// - Abstracting the PPI database abstraction
/// - Creating Hand-Off Blocks (HOBs).
///
struct _EFI_PEI_SERVICES {
  ///
  /// The table header for the PEI Services Table.
  ///
  EFI_TABLE_HEADER                Hdr;
 
  //
  // PPI Functions
  //
  EFI_PEI_INSTALL_PPI             InstallPpi;
  EFI_PEI_REINSTALL_PPI           ReInstallPpi;
  EFI_PEI_LOCATE_PPI              LocatePpi;
  EFI_PEI_NOTIFY_PPI              NotifyPpi;
 
  //
  // Boot Mode Functions
  //
  EFI_PEI_GET_BOOT_MODE           GetBootMode;
  EFI_PEI_SET_BOOT_MODE           SetBootMode;
 
  //
  // HOB Functions
  //
  EFI_PEI_GET_HOB_LIST            GetHobList;
  EFI_PEI_CREATE_HOB              CreateHob;
 
  //
  // Firmware Volume Functions
  //
  EFI_PEI_FFS_FIND_NEXT_VOLUME2   FfsFindNextVolume;
  EFI_PEI_FFS_FIND_NEXT_FILE2     FfsFindNextFile;
  EFI_PEI_FFS_FIND_SECTION_DATA2  FfsFindSectionData;
 
  //
  // PEI Memory Functions
  //
  EFI_PEI_INSTALL_PEI_MEMORY      InstallPeiMemory;
  EFI_PEI_ALLOCATE_PAGES          AllocatePages;
  EFI_PEI_ALLOCATE_POOL           AllocatePool;
  EFI_PEI_COPY_MEM                CopyMem;
  EFI_PEI_SET_MEM                 SetMem;
 
  //
  // Status Code
  //
  EFI_PEI_REPORT_STATUS_CODE      ReportStatusCode;
 
  //
  // Reset
  //
  EFI_PEI_RESET_SYSTEM            ResetSystem;
 
  //
  // (the following interfaces are installed by publishing PEIM)
  // I/O Abstractions
  //
  EFI_PEI_CPU_IO_PPI              *CpuIo;
  EFI_PEI_PCI_CFG2_PPI            *PciCfg;
 
  //
  // Future Installed Services
  //
  EFI_PEI_FFS_FIND_BY_NAME        FfsFindFileByName;
  EFI_PEI_FFS_GET_FILE_INFO       FfsGetFileInfo;
  EFI_PEI_FFS_GET_VOLUME_INFO     FfsGetVolumeInfo;
  EFI_PEI_REGISTER_FOR_SHADOW     RegisterForShadow;
  EFI_PEI_FFS_FIND_SECTION_DATA3  FindSectionData3;
  EFI_PEI_FFS_GET_FILE_INFO2      FfsGetFileInfo2;
  EFI_PEI_RESET2_SYSTEM           ResetSystem2;
  EFI_PEI_FREE_PAGES              FreePages;
};
  • MdeModulePkg\Core\Pei\PeiMain\PeiMain.c
/// Pei service instance
///
EFI_PEI_SERVICES  gPs = {
  {
    PEI_SERVICES_SIGNATURE,
    PEI_SERVICES_REVISION,
    sizeof (EFI_PEI_SERVICES),
    0,
    0
  },
  PeiInstallPpi,
  PeiReInstallPpi,
  PeiLocatePpi,
  PeiNotifyPpi,
 
  PeiGetBootMode,
  PeiSetBootMode,
 
  PeiGetHobList,
  PeiCreateHob,
 
  PeiFfsFindNextVolume,
  PeiFfsFindNextFile,
  PeiFfsFindSectionData,
 
  PeiInstallPeiMemory,
  PeiAllocatePages,
  PeiAllocatePool,
  (EFI_PEI_COPY_MEM)CopyMem,
  (EFI_PEI_SET_MEM)SetMem,
 
  PeiReportStatusCode,
  PeiResetSystem,
 
  &gPeiDefaultCpuIoPpi,
  &gPeiDefaultPciCfg2Ppi,
 
  PeiFfsFindFileByName,
  PeiFfsGetFileInfo,
  PeiFfsGetVolumeInfo,
  PeiRegisterForShadow,
  PeiFfsFindSectionData3,
  PeiFfsGetFileInfo2,
  PeiResetSystem2,
  PeiFreePages,
};

GetHobList(PEI阶段实现)

  • MdeModulePkg\Core\Pei\PeiMain.h
/**
 
  Gets the pointer to the HOB List.
 
 
  @param PeiServices                   An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation.
  @param HobList                       Pointer to the HOB List.
 
  @retval EFI_SUCCESS                  Get the pointer of HOB List
  @retval EFI_NOT_AVAILABLE_YET        the HOB List is not yet published
  @retval EFI_INVALID_PARAMETER        HobList is NULL (in debug mode)
 
**/
EFI_STATUS
EFIAPI
PeiGetHobList (
  IN CONST EFI_PEI_SERVICES  **PeiServices,
  IN OUT VOID          **HobList
  );
  • MdeModulePkg\Core\Pei\Hob\Hob.c
/** 
  Gets the pointer to the HOB List.
 
  @param PeiServices                   An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation.
  @param HobList                       Pointer to the HOB List.
 
  @retval EFI_SUCCESS                  Get the pointer of HOB List
  @retval EFI_NOT_AVAILABLE_YET        the HOB List is not yet published
  @retval EFI_INVALID_PARAMETER        HobList is NULL (in debug mode) 
**/
EFI_STATUS
EFIAPI
PeiGetHobList (
  IN CONST EFI_PEI_SERVICES  **PeiServices,
  IN OUT VOID          **HobList
  )
{
  PEI_CORE_INSTANCE *PrivateData;
 
  //
  // Only check this parameter in debug mode
  //
 
  DEBUG_CODE_BEGIN ();
    if (HobList == NULL) {
      return EFI_INVALID_PARAMETER;
    }
  DEBUG_CODE_END ();
 
  PrivateData = PEI_CORE_INSTANCE_FROM_PS_THIS(PeiServices);
 
  *HobList    = PrivateData->HobList.Raw;
 
  return EFI_SUCCESS;
}
  • PeiMain.h

这个宏的作用是根据一个结构体成员变量的的地址获得该结构体基地址

定义形式：
#define _CR(Record, TYPE, Field)
((TYPE *) ((CHAR8 *) (Record) - (CHAR8 *) &(((TYPE *) 0)->Field)))
功能是：找出TYPE类型结构体成员Field所在结构体的地址,Record是Field的地址。

具体实现：
1.(CHAR8 *) (Record)：Field的地址以CHAR8 *类型进行运算。

2.(CHAR8 *) &(((TYPE *) 0)->Field))：重点就是(TYPE *) 0)了，ANSI C标准允许值为0的常量被强制转换成任何一种类型的指针，并且转换结果是一个NULL指针，因此((type *)0)的结果就是一个类型为type *的NULL指针。如果利用这NULL指针来访问type的成员当然是非法的，但&( ((type *)0)->field )的意图仅仅是计算field字段的地址。聪明的编译器根本就不生成访问type的代码，而仅仅是根据type的内存布局和结构体实例首址在编译期计算这个（常量）地址，这样就完全避免了通过NULL指针访问内存的问题。又因为首址为0，所以这个地址的值就是字段相对于结构体基址的偏移。以上方法避免了实例化一个type对象，并且求值在编译期进行，没有运行期负担。这样，就得到了Field在它的结构体中的偏移地址并同样以CHAR8 *类型进行运算。

3.((TYPE *) ：最后求得的地址转成原有结构体类型。
用1得到的变量地址减去2得到的变量偏移地址，得到的基地址通过3转换回原来的类型。大功告成！
重点就是 ((TYPE *) 0)->Field)。

 ///
/// Pei Core Instance Data Macros
///
#define PEI_CORE_INSTANCE_FROM_PS_THIS(a) \
  CR(a, PEI_CORE_INSTANCE, Ps, PEI_CORE_HANDLE_SIGNATURE)

GetHobList(DXE阶段实现)

  • MdePkg\Library\DxeHobLib\HobLib.c
VOID  *mHobList = NULL;
 
/**
  Returns the pointer to the HOB list.
 
  This function returns the pointer to first HOB in the list.
  For PEI phase, the PEI service GetHobList() can be used to retrieve the pointer
  to the HOB list.  For the DXE phase, the HOB list pointer can be retrieved through
  the EFI System Table by looking up theHOB list GUID in the System Configuration Table.
  Since the System Configuration Table does not exist that the time the DXE Core is
  launched, the DXE Core uses a global variable from the DXE Core Entry Point Library
  to manage the pointer to the HOB list.
 
  If the pointer to the HOB list is NULL, then ASSERT().
 
  This function also caches the pointer to the HOB list retrieved.
 
  @return The pointer to the HOB list.
 
**/
VOID *
EFIAPI
GetHobList (
  VOID
  )
{
  EFI_STATUS  Status;
 
  if (mHobList == NULL) {
    Status = EfiGetSystemConfigurationTable (&gEfiHobListGuid, &mHobList);
    ASSERT_EFI_ERROR (Status);
    ASSERT (mHobList != NULL);
  }
  return mHobList;
}
/**
  Retrieves a pointer to the system configuration table from the EFI System Table
  based on a specified GUID.
 
  This function searches the list of configuration tables stored in the EFI System Table
  for a table with a GUID that matches TableGuid.  If a match is found, then a pointer to
  the configuration table is returned in Table., and EFI_SUCCESS is returned. If a matching GUID
  is not found, then EFI_NOT_FOUND is returned.
  If TableGuid is NULL, then ASSERT().
  If Table is NULL, then ASSERT().
 
  @param  TableGuid       The pointer to table's GUID type.
  @param  Table           The pointer to the table associated with TableGuid in the EFI System Table.
 
  @retval EFI_SUCCESS     A configuration table matching TableGuid was found.
  @retval EFI_NOT_FOUND   A configuration table matching TableGuid could not be found.
 
**/
EFI_STATUS
EFIAPI
EfiGetSystemConfigurationTable (
  IN  EFI_GUID  *TableGuid,
  OUT VOID      **Table
  )
{
  EFI_SYSTEM_TABLE  *SystemTable;
  UINTN             Index;
 
  ASSERT (TableGuid != NULL);
  ASSERT (Table != NULL);
 
  SystemTable = gST;
  *Table = NULL;
  for (Index = 0; Index < SystemTable->NumberOfTableEntries; Index++) {
    if (CompareGuid (TableGuid, &(SystemTable->ConfigurationTable[Index].VendorGuid))) {
      *Table = SystemTable->ConfigurationTable[Index].VendorTable;
      return EFI_SUCCESS;
    }
  }
 
  return EFI_NOT_FOUND;
}

GetNextHob

/**
  Returns the next instance of a HOB type from the starting HOB.
 
  This function searches the first instance of a HOB type from the starting HOB pointer.
  If there does not exist such HOB type from the starting HOB pointer, it will return NULL.
  In contrast with macro GET_NEXT_HOB(), this function does not skip the starting HOB pointer
  unconditionally: it returns HobStart back if HobStart itself meets the requirement;
  caller is required to use GET_NEXT_HOB() if it wishes to skip current HobStart.
 
  If HobStart is NULL, then ASSERT().
 
  @param  Type          The HOB type to return.
  @param  HobStart      The starting HOB pointer to search from.
 
  @return The next instance of a HOB type from the starting HOB.
 
**/
VOID *
EFIAPI
GetNextHob (
  IN UINT16                 Type,
  IN CONST VOID             *HobStart
  )
{
  EFI_PEI_HOB_POINTERS  Hob;
 
  ASSERT (HobStart != NULL);
 
  Hob.Raw = (UINT8 *) HobStart;
  //
  // Parse the HOB list until end of list or matching type is found.
  //
  while (!END_OF_HOB_LIST (Hob)) {
    if (Hob.Header->HobType == Type) {
      return Hob.Raw;
    }
    Hob.Raw = GET_NEXT_HOB (Hob);
  }
  return NULL;
}

GetFirstHob

/**
  Returns the first instance of a HOB type among the whole HOB list.
 
  This function searches the first instance of a HOB type among the whole HOB list.
  If there does not exist such HOB type in the HOB list, it will return NULL.
 
  If the pointer to the HOB list is NULL, then ASSERT().
 
  @param  Type          The HOB type to return.
 
  @return The next instance of a HOB type from the starting HOB.
 
**/
VOID *
EFIAPI
GetFirstHob (
  IN UINT16                 Type
  )
{
  VOID      *HobList;
 
  HobList = GetHobList ();
  return GetNextHob (Type, HobList);
}

GetNextGuidHob

/**
  Returns the next instance of the matched GUID HOB from the starting HOB.
 
  This function searches the first instance of a HOB from the starting HOB pointer.
  Such HOB should satisfy two conditions:
  its HOB type is EFI_HOB_TYPE_GUID_EXTENSION and its GUID Name equals to the input Guid.
  If there does not exist such HOB from the starting HOB pointer, it will return NULL.
  Caller is required to apply GET_GUID_HOB_DATA () and GET_GUID_HOB_DATA_SIZE ()
  to extract the data section and its size information, respectively.
  In contrast with macro GET_NEXT_HOB(), this function does not skip the starting HOB pointer
  unconditionally: it returns HobStart back if HobStart itself meets the requirement;
  caller is required to use GET_NEXT_HOB() if it wishes to skip current HobStart.
 
  If Guid is NULL, then ASSERT().
  If HobStart is NULL, then ASSERT().
 
  @param  Guid          The GUID to match with in the HOB list.
  @param  HobStart      A pointer to a Guid.
 
  @return The next instance of the matched GUID HOB from the starting HOB.
 
**/
VOID *
EFIAPI
GetNextGuidHob (
  IN CONST EFI_GUID         *Guid,
  IN CONST VOID             *HobStart
  )
{
  EFI_PEI_HOB_POINTERS  GuidHob;
 
  GuidHob.Raw = (UINT8 *) HobStart;
  while ((GuidHob.Raw = GetNextHob (EFI_HOB_TYPE_GUID_EXTENSION, GuidHob.Raw)) != NULL) {
    if (CompareGuid (Guid, &GuidHob.Guid->Name)) {
      break;
    }
    GuidHob.Raw = GET_NEXT_HOB (GuidHob);
  }
  return GuidHob.Raw;
}

GetFirstGuidHob

/**
  Returns the first instance of the matched GUID HOB among the whole HOB list.
 
  This function searches the first instance of a HOB among the whole HOB list.
  Such HOB should satisfy two conditions:
  its HOB type is EFI_HOB_TYPE_GUID_EXTENSION and its GUID Name equals to the input Guid.
  If there does not exist such HOB from the starting HOB pointer, it will return NULL.
  Caller is required to apply GET_GUID_HOB_DATA () and GET_GUID_HOB_DATA_SIZE ()
  to extract the data section and its size information, respectively.
 
  If the pointer to the HOB list is NULL, then ASSERT().
  If Guid is NULL, then ASSERT().
 
  @param  Guid          The GUID to match with in the HOB list.
 
  @return The first instance of the matched GUID HOB among the whole HOB list.
 
**/
VOID *
EFIAPI
GetFirstGuidHob (
  IN CONST EFI_GUID         *Guid
  )
{
  VOID      *HobList;
 
  HobList = GetHobList ();
  return GetNextGuidHob (Guid, HobList);
}

HOB生产消费流程

PHIT HOB的建立

  • MdeModulePkg\Core\Pei\Hob\Hob.c
/**
 
  Builds a Handoff Information Table HOB
 
  @param BootMode        - Current Bootmode
  @param MemoryBegin     - Start Memory Address.
  @param MemoryLength    - Length of Memory.
 
  @return EFI_SUCCESS Always success to initialize HOB.
 
**/
EFI_STATUS
PeiCoreBuildHobHandoffInfoTable (
  IN EFI_BOOT_MODE         BootMode,
  IN EFI_PHYSICAL_ADDRESS  MemoryBegin,
  IN UINT64                MemoryLength
  )
{
  EFI_HOB_HANDOFF_INFO_TABLE   *Hob;
  EFI_HOB_GENERIC_HEADER       *HobEnd;
 
  Hob                      = (VOID *)(UINTN)MemoryBegin;
  HobEnd                   = (EFI_HOB_GENERIC_HEADER*) (Hob+1);
  Hob->Header.HobType      = EFI_HOB_TYPE_HANDOFF;
  Hob->Header.HobLength    = (UINT16) sizeof (EFI_HOB_HANDOFF_INFO_TABLE);
  Hob->Header.Reserved     = 0;
 
  HobEnd->HobType          = EFI_HOB_TYPE_END_OF_HOB_LIST;
  HobEnd->HobLength        = (UINT16) sizeof (EFI_HOB_GENERIC_HEADER);
  HobEnd->Reserved         = 0;
 
  Hob->Version             = EFI_HOB_HANDOFF_TABLE_VERSION;
  Hob->BootMode            = BootMode;
 
  Hob->EfiMemoryTop        = MemoryBegin + MemoryLength;
  Hob->EfiMemoryBottom     = MemoryBegin;
  Hob->EfiFreeMemoryTop    = MemoryBegin + MemoryLength;
  Hob->EfiFreeMemoryBottom = (EFI_PHYSICAL_ADDRESS) (UINTN) (HobEnd + 1);
  Hob->EfiEndOfHobList     = (EFI_PHYSICAL_ADDRESS) (UINTN) HobEnd;
 
  return EFI_SUCCESS;
}

头和尾HOB建立后，CreateHob会覆盖尾HOB，再将尾HOB后移，此时PEI阶段的模块会相继创建各种类型的HOB，我们可以在PEI阶段自己创建HOB传递一些数据，也可以在PEI和DXE阶段找到感兴趣的HOB块，对其BLOCK数据块进行操作，但是理论上在DXE阶段使用Get方法，不建议在PEI阶段使用，是因为不确定Get的HOB是否已经建立，即无法判断两个Pei ModulePart的执行顺序，当然也可以通过Deepx来限定ModulePart跑的顺序

作业Demo

HOB Homework

  • OemHob.h
#ifndef __OEM_HOB_H__
#define __OEM_HOB_H__
#ifdef __cplusplus
extern "C" {
#endif


#define OEM_HOB_GUID \
    {0xe73e6c2b, 0xaa9a, 0x4b51, 0x94, 0x56, 0x50, 0xd2, 0x8b, 0xcc, 0x57, 0xf3}

typedef struct _OEM_HOB{   
    
    EFI_HOB_GUID_TYPE GuidExtension;
    CHAR8 OemString[10];
    UINT16 MemorySpace;  
    
} OEM_HOB;
/****** DO NOT WRITE BELOW THIS LINE *******/
#ifdef __cplusplus
}
#endif
#endif
  • PeiCreateHob.c
#include <AmiPeiLib.h>
#include <Library/PeiServicesLib.h>
#include <Library/HobLib.h>
#include <OemHob.h>
#include <MemInfoHob.h>

extern EFI_GUID gSiMemoryInfoDataGuid;

EFI_STATUS PeiCreateHobEntryPoint(
   IN EFI_PEI_FILE_HANDLE   FileHandle,
   IN CONST EFI_PEI_SERVICES  **PeiServices
)
{
    EFI_STATUS    Status = EFI_SUCCESS;
    OEM_HOB       *pHob     = NULL;
    VOID          *Memory_Hob  = NULL;
    EFI_GUID      OemHobGuid = OEM_HOB_GUID;
    EFI_GUID      MemoryInfoDataGuid = gSiMemoryInfoDataGuid;
    //CHAR8         BIOSVersion[] = CONVERT_TO_STRING(PLATFORM_NAME);
    CHAR8         BIOSVersion[10]="kabylake";
    UINT16        MemorySize = 0;

    // Get physical address bits supported.
    Memory_Hob = GetFirstGuidHob(&MemoryInfoDataGuid);
    if (Memory_Hob != NULL) {
        MemorySize = ((MEMORY_INFO_DATA_HOB *) Memory_Hob)->TotalPhysicalMemorySize;
        DEBUG((-1,"\nElder has been got MemoryInfoDataHob in Pei Phase!"));
        DEBUG((-1,"\nMemoryInfoDataHob Address : %p",Memory_Hob));
      } 
    
    
    //create HOB for DXE
    Status = (*PeiServices)->CreateHob (PeiServices,
                                        EFI_HOB_TYPE_GUID_EXTENSION, 
                                        sizeof(OEM_HOB), 
                                        &pHob);
    if (!EFI_ERROR(Status)){
           
           pHob->GuidExtension.Name = OemHobGuid;
           Strcpy(pHob->OemString,BIOSVersion);
           pHob->MemorySpace = MemorySize;           
           DEBUG((-1,"\nElder has been Created OemHob Success in Pei Phase!"));           
       }
        	
	return EFI_SUCCESS;
}
  • DxeFindHob.c
#include <AmiDxeLib.h>
#include <Library/HobLib.h>
#include <OemHob.h>

EFI_STATUS DxeFindHobEntryPoint(
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
)
{
    EFI_STATUS      Status = EFI_SUCCESS;
    EFI_GUID        OemHobGuid = OEM_HOB_GUID;
    OEM_HOB         *pHob = NULL;
       
    InitAmiLib (ImageHandle , SystemTable) ;
    pHob = (OEM_HOB*)GetFirstGuidHob (&OemHobGuid);
               
    if (pHob == NULL)
        {
            DEBUG((-1,"\n Elder Dxe Phase return OemHob Data Error!\n"));
        }
    else
        {
            DEBUG((-1,"\n Elder OemHob Address = %p\n",pHob));    
            DEBUG((-1,"\n Elder Dxe Phase has been got HobData OemString = %s\n",pHob->OemString));
            DEBUG((-1,"\n Elder Dxe Phase has been got HobData MemorySpace = %d MB\n",pHob->MemorySpace));
        }
     
	return EFI_SUCCESS;
}
文章作者: Holy Chen
文章链接: http://holychen.cn/2021/08/01/HOB/
版权声明: 本博客所有文章除特別声明外，均采用 CC BY 4.0 许可协议。转载请注明来源 Holy Chen !
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