SecCore关键数据结构

SEC_IDT_TABLE 数据结构

typedef struct _SEC_IDT_TABLE {  //  // Reserved 8 bytes preceding IDT to store EFI_PEI_SERVICES**, since IDT base  // address should be 8-byte alignment.  // Note: For IA32, only the 4 bytes immediately preceding IDT is used to store  // EFI_PEI_SERVICES**  //  UINT64            PeiService;  UINT64            IdtTable[SEC_IDT_ENTRY_COUNT];} SEC_IDT_TABLE;

IDT 

EFI_SEC_PEI_HAND_OFF 数据结构

       EFI_SEC_PEI_HAND_OFF 数据结构含有SEC-PEI Core 握手交接控制权时的所需信息，如临时RAM 的地址大小，栈的地址和Boot 

Firmware Volume 的地址，这些信息PEI Core 执行时都需要用到。

////// EFI_SEC_PEI_HAND_OFF structure holds information about/// PEI core's operating environment, such as the size of location of/// temporary RAM, the stack location and BFV location./// typedef struct _EFI_SEC_PEI_HAND_OFF {  ///  /// Size of the data structure.  ///   UINT16  DataSize;  ///  /// Points to the first byte of the boot firmware volume,    指向 boot firmware volume 第一个字节  /// which the PEI Dispatcher should search for   /// PEI modules.  ///   VOID    *BootFirmwareVolumeBase;  ///  /// Size of the boot firmware volume, in bytes.              firmware volume 的大小，单位是byte（字节）  ///   UINTN   BootFirmwareVolumeSize;  ///  /// Points to the first byte of the temporary RAM.           指向临时RAM的第一个字节  ///   VOID    *TemporaryRamBase;  ///  /// Size of the temporary RAM, in bytes.                     临时RAM的大小  ///   UINTN   TemporaryRamSize;  ///  /// Points to the first byte of the temporary RAM   /// available for use by the PEI Foundation. The area   /// described by PeiTemporaryRamBase and PeiTemporaryRamSize   /// must not extend outside beyond the area described by  /// TemporaryRamBase & TemporaryRamSize. This area should not  /// overlap with the area reported by StackBase and   /// StackSize.  ///  VOID    *PeiTemporaryRamBase;  ///  /// The size of the available temporary RAM available for   /// use by the PEI Foundation, in bytes.  ///   UINTN   PeiTemporaryRamSize;  ///  /// Points to the first byte of the stack.   /// This are may be part of the memory described by   /// TemporaryRamBase and TemporaryRamSize   /// or may be an entirely separate area.  ///   VOID    *StackBase;  ///  /// Size of the stack, in bytes.  ///   UINTN   StackSize;} EFI_SEC_PEI_HAND_OFF;

这个结构体所包含的信息，注释已经说得非常清楚了，主要就是pei core 的执行环境，RAM 的起始位置，大小，stack 的大小，起始位置。

2.4  数据结构关系图

     FindAndReportEntryPoints 函数在flash 中寻找PEI Core 并返回其入口地址

TemporaryRamMigration 函数

          TemporaryRamMigration函数把c 代码运行所需要的栈和堆从临时memory (cache as ram) 切换到常规内存（主memory), 别看Migration 这个单词逼格很高，其实质就是copy 的意思。

/**  This service of the TEMPORARY_RAM_SUPPORT_PPI that migrates temporary RAM into  permanent memory.  @param[in] PeiServices            Pointer to the PEI Services Table.  @param[in] TemporaryMemoryBase    Source Address in temporary memory from which the SEC or PEIM will copy the                                Temporary RAM contents.  @param[in] PermanentMemoryBase    Destination Address in permanent memory into which the SEC or PEIM will copy the                                Temporary RAM contents.  @param[in] CopySize               Amount of memory to migrate from temporary to permanent memory.  @retval EFI_SUCCESS           The data was successfully returned.  @retval EFI_INVALID_PARAMETER PermanentMemoryBase + CopySize > TemporaryMemoryBase when                                TemporaryMemoryBase > PermanentMemoryBase.**/EFI_STATUSEFIAPISecTemporaryRamSupport (  IN CONST EFI_PEI_SERVICES   **PeiServices,  IN EFI_PHYSICAL_ADDRESS     TemporaryMemoryBase,  IN EFI_PHYSICAL_ADDRESS     PermanentMemoryBase,  IN UINTN                    CopySize  ){  IA32_DESCRIPTOR   IdtDescriptor;  VOID*             OldHeap;  VOID*             NewHeap;  VOID*             OldStack;  VOID*             NewStack;  UINTN             HeapSize;  UINTN             StackSize;  HeapSize   = CopySize * PcdGet8 (PcdFspHeapSizePercentage) / 100 ;  StackSize  = CopySize - HeapSize;      OldHeap = (VOID*)(UINTN)TemporaryMemoryBase;  NewHeap = (VOID*)((UINTN)PermanentMemoryBase + StackSize);  OldStack = (VOID*)((UINTN)TemporaryMemoryBase + HeapSize);  NewStack = (VOID*)(UINTN)PermanentMemoryBase;  //  // Migrate Heap  //  CopyMem (NewHeap, OldHeap, HeapSize);  //  // Migrate Stack  //  CopyMem (NewStack, OldStack, StackSize);  //  // We need *not* fix the return address because currently,  // The PeiCore is executed in flash.  //  //  // Rebase IDT table in permanent memory  //  AsmReadIdtr (&IdtDescriptor);  IdtDescriptor.Base = IdtDescriptor.Base - (UINTN)OldStack + (UINTN)NewStack;  AsmWriteIdtr (&IdtDescriptor);  //  // Fixed the FSP data pointer  //  FspDataPointerFixUp ((UINTN)NewStack - (UINTN)OldStack);  //  // SecSwitchStack function must be invoked after the memory migration  // immediatly, also we need fixup the stack change caused by new call into  // permenent memory.  //  SecSwitchStack (    (UINT32) (UINTN) OldStack,    (UINT32) (UINTN) NewStack    );  return EFI_SUCCESS;}

所谓迁移（migration) , 就是从一个地方搬到另一个地方，还有搬多少内容。即目的地，源地址，还有大小，而这个函数的三个参数刚好与这三个因素

匹配。