FpgaPlatformEarlyInit - FPGA Platform Early Initialization PEIM

Module Information

Source Files (from debug strings)

• PurleyPlatPkg/Platform/Pei/FpgaPlatformInit/FpgaPlatformEarlyInit.c - Main entry
• PurleyPlatPkg/Platform/Pei/FpgaPlatformInit/FpgaBbsInit.c - BBS init
• PurleyPlatPkg/Library/FpgaPlatformHooksLib/FpgaPlatformHooksLib.c - Platform hooks
• MdePkg/Library/BaseMemoryLibRepStr/CopyMemWrapper.c
• MdePkg/Library/BaseMemoryLibRepStr/ZeroMemWrapper.c
• MdePkg/Library/BaseLib/CheckSum.c
• MdePkg/Library/BaseLib/Unaligned.c
• MdePkg/Library/BaseLib/X86ReadIdtr.c
• MdePkg/Library/PeiHobLib/HobLib.c
• MdePkg/Library/PeiPcdLib/PeiPcdLib.c
• MdePkg/Library/PeiServicesLib/PeiServicesLib.c
• MdePkg/Library/PeiServicesTablePointerLibIdt/PeiServicesTablePointer.c

Segments

Function Map

FPGA Platform-Specific Functions

HOB Library (PEI)

PEI Services / PPI Access

Internal Library Functions

GUIDs Used (in .data section)

FPGA Configuration HOB Layout (38 bytes)

Based on FpgaGetConfigHob, FpgaConfigGetHobValues, and FpgaConfigSetHobValues:

Flow Diagram

ModuleEntryPoint()

  +-- FpgaReportStatusCode("Entry")
  +-- FpgaConfigGetHobValues()  -- read socket config from HOB
     +-- FpgaGetConfigHob()
     |     +-- GetHobList()
     |     +-- GetNextHobByType() -- search for FPGA config HOB by GUID
     |     +-- [if not found]: FpgaBuildConfigHob()
     |     |     +-- GetHobByType(4, 62)
     |     |     +-- CopyGuid()
     |     |     +-- InternalCopyMem()
     |     +-- [if variable exists]: FpgaGetConfigVariable()
     |           +-- PeiAllocateZeroPool()
     |           +-- PeiGetPcdProtocol()/GetVariable()
     +-- Copy data from HOB to local buffer

  +-- Locate gEfiPeiMrcHooksChipServicesPpiGuid
     [success] --> Locate gEfiPeiMpServicesPpiGuid
                   |     +-- PeiGetPcdProtocol() -> PcdGet(12)
                   +-- JUMP to BBS init path

  +-- [if MRC failure] --> FpgaReportStatusCode / ASSERT
  +-- [if no socket present] --> EFI_NOT_FOUND

BBS Init path (via ModuleEntryPoint):
  FpgaBbsInit()
    +-- FpgaReportStatusCode()
    +-- Locate gEfiPeiBootInRecoveryBootModePpiGuid
    +-- Allocate memory (type 3, 0x2000 bytes)
    +-- Load FV from BIOS offset (0xA00000 = 10MB)
     (calls gEfiPeiBootInRecoveryBootModePpi->LoadFvImage)
    +-- Verify FV signature (0x48534646 = "FSFH")
    +-- InternalCalculateCheckSum16() -- verify checksum
    +-- FpgaInstallFvInfoPpi() -- register FV with PEI
     +-- PeiAllocatePool()
     +-- CopyGuid() with gEfiFirmwareFileSystem2Guid
     +-- Install PPI via PeiServices->InstallPpi()
    +-- BuildFvHob() -- register FV in HOB database

Key Observations

1. Socket configuration: The module manages configuration for up to 4 CPU sockets, tracking socket presence, BBS indices, HSSI card IDs, and platform types.

2. FPGA FV loading: FpgaBbsInit loads a firmware volume from flash (offset 0xA00000 = 10MB into SPI flash), validates its signature and checksum, then registers it with the PEI infrastructure so other modules can discover it.

3. Dual PPI paths: The entry point first tries MRC Hooks Chip Services PPI. If successful, it also looks for Mp Services PPI. If MRC hooks fail, it asserts and returns unsupported.

4. HOBO-based config: The FPGA configuration is HOB-backed (created during PEI phase and passed to DXE phase). The module creates the HOB if it doesn't exist, initializing from UEFI variable "FpgaSocketConfig" if available.

5. Inline memory/string lib: Many BaseMemoryLib functions are inlined from MdePkg, indicating this is a minimal-dependency PEIM that doesn't link against the full BaseMemoryLib.