Function PatchACPI_OtherOS

rEFIt_UEFI/Platform/AcpiPatcher.cpp:2398–2534

* Patches UEFI ACPI tables with tables found in OsSubdir. */

 * Patches UEFI ACPI tables with tables found in OsSubdir.
 */
EFI_STATUS PatchACPI_OtherOS(CONST CHAR16* OsSubdir, BOOLEAN DropSSDT)
{
  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER    *RsdPointer;
  EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE       *FadtPointer;

  EFI_STATUS            Status; // = EFI_SUCCESS;
  //  UINTN                 Index;
  REFIT_DIR_ITER        DirIter;
  EFI_FILE_INFO         *DirEntry;

  //
  // Search for RSDP in UEFI SystemTable/ConfigTable (first Acpi 2.0, then 1.0)
  //
  RsdPointer = NULL;

  Status = EfiGetSystemConfigurationTable (&gEfiAcpi20TableGuid, (VOID **) &RsdPointer);
  if (RsdPointer != NULL) {
	  DBG("OtherOS: Found Acpi 2.0 RSDP 0x%llX\n", (uintptr_t)RsdPointer);
  } else {
    Status = EfiGetSystemConfigurationTable (&gEfiAcpi10TableGuid, (VOID **) &RsdPointer);
    if (RsdPointer != NULL) {
		DBG("Found Acpi 1.0 RSDP 0x%llX\n", (uintptr_t)RsdPointer);
    }
  }
  // if RSDP not found - quit
  if (!RsdPointer) {
    return Status;
  }

  //
  // Find RSDT and/or XSDT
  //
  Rsdt = (RSDT_TABLE*)(UINTN)(RsdPointer->RsdtAddress);
  if (Rsdt != NULL && Rsdt->Header.Signature != EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) {
    Rsdt = NULL;
  }
  DBG("RSDT at 0x%llX\n", (UINTN)Rsdt);

  // check for XSDT
  Xsdt = NULL;
  if (RsdPointer->Revision >=2 && (RsdPointer->XsdtAddress < (UINT64)((UINTN)(-1)))) {
    Xsdt = (XSDT_TABLE*)(UINTN)RsdPointer->XsdtAddress;
    if (Xsdt != NULL && Xsdt->Header.Signature != EFI_ACPI_2_0_EXTENDED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) {
      Xsdt = NULL;
    }
  }
  DBG("XSDT at 0x%llX\n", (UINTN)Xsdt);

  // if RSDT and XSDT not found - quit
  if (Rsdt == NULL && Xsdt == NULL) {
    return EFI_UNSUPPORTED;
  }

  //
  // Take FADT (FACP) from XSDT or RSDT (always first entry)
  //
  FadtPointer = NULL;
  if (Xsdt) {