ArmVirtPkg/PlatformHasAcpiDtDxe/PlatformHasAcpiDtDxe.c

   1 /** @file
   2   Decide whether the firmware should expose an ACPI- and/or a Device Tree-based
   3   hardware description to the operating system.
   4
   5   Copyright (c) 2017, Red Hat, Inc.
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8 **/
   9
  10 #include <Guid/PlatformHasAcpi.h>
  11 #include <Guid/PlatformHasDeviceTree.h>
  12 #include <Library/BaseLib.h>
  13 #include <Library/DebugLib.h>
  14 #include <Library/PcdLib.h>
  15 #include <Library/QemuFwCfgLib.h>
  16 #include <Library/UefiBootServicesTableLib.h>
  17
  18 EFI_STATUS
  19 EFIAPI
  20 PlatformHasAcpiDt (
  21   IN EFI_HANDLE        ImageHandle,
  22   IN EFI_SYSTEM_TABLE  *SystemTable
  23   )
  24 {
  25   EFI_STATUS            Status;
  26   FIRMWARE_CONFIG_ITEM  FwCfgItem;
  27   UINTN                 FwCfgSize;
  28
  29   //
  30   // If we fail to install any of the necessary protocols below, the OS will be
  31   // unbootable anyway (due to lacking hardware description), so tolerate no
  32   // errors here.
  33   //
  34   if ((MAX_UINTN == MAX_UINT64) &&
  35       !PcdGetBool (PcdForceNoAcpi) &&
  36       !EFI_ERROR (
  37          QemuFwCfgFindFile (
  38            "etc/table-loader",
  39            &FwCfgItem,
  40            &FwCfgSize
  41            )
  42          ))
  43   {
  44     //
  45     // Only make ACPI available on 64-bit systems, and only if QEMU generates
  46     // (a subset of) the ACPI tables.
  47     //
  48     Status = gBS->InstallProtocolInterface (
  49                     &ImageHandle,
  50                     &gEdkiiPlatformHasAcpiGuid,
  51                     EFI_NATIVE_INTERFACE,
  52                     NULL
  53                     );
  54     if (EFI_ERROR (Status)) {
  55       goto Failed;
  56     }
  57
  58     return Status;
  59   }
  60
  61   //
  62   // Expose the Device Tree otherwise.
  63   //
  64   Status = gBS->InstallProtocolInterface (
  65                   &ImageHandle,
  66                   &gEdkiiPlatformHasDeviceTreeGuid,
  67                   EFI_NATIVE_INTERFACE,
  68                   NULL
  69                   );
  70   if (EFI_ERROR (Status)) {
  71     goto Failed;
  72   }
  73
  74   return Status;
  75
  76 Failed:
  77   ASSERT_EFI_ERROR (Status);
  78   CpuDeadLoop ();
  79   //
  80   // Keep compilers happy.
  81   //
  82   return Status;
  83 }