uefi bios pei 階段最重要的一個數據結構（結構體）
阿新 • • 發佈：2019-02-05
在PEI階段，全域性變數大概有這麼幾個： gPs PEI Service 結構的實現，包括所有的PEI 服務的函式指標。比如學見的PeiInstallPPi, PeiCreateHob, PeiSetSystem.
其次就是PrivateData， 這個是今天我們要討論的問題，其型別為 PEI_CORE_INSTANCE.
具體就是長這個樣子：
struct _PEI_CORE_INSTANCE { 184 UINTN Signature; 185 189 EFI_PEI_SERVICES *Ps; 190 PEI_PPI_DATABASE PpiData; 191 195 UINTN FvCount; 196 201 PEI_CORE_FV_HANDLE *Fv; 202 207 PEI_CORE_UNKNOW_FORMAT_FV_INFO *UnknownFvInfo; 208 UINTN UnknownFvInfoCount; 209 213 EFI_PEI_FILE_HANDLE *CurrentFvFileHandles; 214 UINTN AprioriCount; 215 UINTN CurrentPeimFvCount; 216 UINTN CurrentPeimCount; 217 EFI_PEI_FILE_HANDLE CurrentFileHandle; 218 BOOLEAN PeimNeedingDispatch; 219 BOOLEAN PeimDispatchOnThisPass; 220 BOOLEAN PeimDispatcherReenter; 221 EFI_PEI_HOB_POINTERS HobList; 222 BOOLEAN SwitchStackSignal; 223 BOOLEAN PeiMemoryInstalled; 224 VOID *CpuIo; 225 EFI_PEI_SECURITY2_PPI *PrivateSecurityPpi; 226 EFI_PEI_SERVICES ServiceTableShadow; 227 EFI_PEI_PPI_DESCRIPTOR *XipLoadFile; 228 EFI_PHYSICAL_ADDRESS PhysicalMemoryBegin; 229 UINT64 PhysicalMemoryLength; 230 EFI_PHYSICAL_ADDRESS FreePhysicalMemoryTop; 231 UINTN HeapOffset; 232 BOOLEAN HeapOffsetPositive; 233 UINTN StackOffset; 234 BOOLEAN StackOffsetPositive; 235 PEICORE_FUNCTION_POINTER ShadowedPeiCore; 236 CACHE_SECTION_DATA CacheSection; 237 // 238 // For Loading modules at fixed address feature to cache the top address below which the 239 // Runtime code, boot time code and PEI memory will be placed. Please note that the offset between this field 240 // and Ps should not be changed since maybe user could get this top address by using the offet to Ps. 241 // 242 EFI_PHYSICAL_ADDRESS LoadModuleAtFixAddressTopAddress; 243 // 244 // The field is define for Loading modules at fixed address feature to tracker the PEI code 245 // memory range usage. It is a bit mapped array in which every bit indicates the correspoding memory page 246 // available or not. 247 // 248 UINT64 *PeiCodeMemoryRangeUsageBitMap; 249 // 250 // This field points to the shadowed image read function 251 // 252 PE_COFF_LOADER_READ_FILE ShadowedImageRead; 253 254 // 255 // Pointer to the temp buffer with the PcdPeiCoreMaxPeimPerFv + 1 number of entries. 256 // 257 EFI_PEI_FILE_HANDLE *FileHandles; 258 // 259 // Pointer to the temp buffer with the PcdPeiCoreMaxPeimPerFv number of entries. 260 // 261 EFI_GUID *FileGuid; 262 263 // 264 // Temp Memory Range is not covered by PeiTempMem and Stack. 265 // Those Memory Range will be migrated into phisical memory. 266 // 267 HOLE_MEMORY_DATA HoleData[HOLE_MAX_NUMBER]; 268 };
PrivateData 我們通常叫做PeiMain的內部資料結構，維護執行PEI階段所有需要的資料資訊，包括PEI 服務， FV 資料空間，PEI 模組的dispatch 狀態， 可使用的記憶體空間等等，由於pei 早期沒有記憶體可用，PeiMain定義了一個該資料的區域性變數，把其儲存在PeiMain入口函式的棧上，而PeiMain 的入口函式在整個PEI 階段並不會退出，所以棧上的資料可作為全域性資料使用，但是全域性變數的地址需要函式引數在不同的函式之間傳遞。
PEI_CORE_FV_HANDLE 資料結構
此資料結構用來記錄一個PeiMain 識別的FV空間的資料資訊，包括其起始位置，資料格式解析的PPI， 自己的控制代碼以及所包含的每個PEI模組的派遣狀態和每個檔案的控制代碼，
它的真實樣子是這樣的：
typedef struct { 110 EFI_FIRMWARE_VOLUME_HEADER *FvHeader; 111 EFI_PEI_FIRMWARE_VOLUME_PPI *FvPpi; 112 EFI_PEI_FV_HANDLE FvHandle; 113 // 114 // Ponter to the buffer with the PcdPeiCoreMaxPeimPerFv number of Entries. 115 // 116 UINT8 *PeimState; 117 // 118 // Ponter to the buffer with the PcdPeiCoreMaxPeimPerFv number of Entries. 119 // 120 EFI_PEI_FILE_HANDLE *FvFileHandles; 121 BOOLEAN ScanFv; 122 UINT32 AuthenticationStatus; 123 } PEI_CORE_FV_HANDLE;