ArmVirtPkg/XenPlatformHasAcpiDtDxe/XenPlatformHasAcpiDtDxe.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/UefiBootServicesTableLib.h>
  15
  16 EFI_STATUS
  17 EFIAPI
  18 XenPlatformHasAcpiDt (
  19   IN EFI_HANDLE        ImageHandle,
  20   IN EFI_SYSTEM_TABLE  *SystemTable
  21   )
  22 {
  23   EFI_STATUS  Status;
  24
  25   //
  26   // If we fail to install any of the necessary protocols below, the OS will be
  27   // unbootable anyway (due to lacking hardware description), so tolerate no
  28   // errors here.
  29   //
  30   // Always make ACPI available on 64-bit systems.
  31   //
  32   if (MAX_UINTN == MAX_UINT64) {
  33     Status = gBS->InstallProtocolInterface (
  34                     &ImageHandle,
  35                     &gEdkiiPlatformHasAcpiGuid,
  36                     EFI_NATIVE_INTERFACE,
  37                     NULL
  38                     );
  39     if (EFI_ERROR (Status)) {
  40       goto Failed;
  41     }
  42   }
  43
  44   //
  45   // Expose the Device Tree unconditionally.
  46   //
  47   Status = gBS->InstallProtocolInterface (
  48                   &ImageHandle,
  49                   &gEdkiiPlatformHasDeviceTreeGuid,
  50                   EFI_NATIVE_INTERFACE,
  51                   NULL
  52                   );
  53   if (EFI_ERROR (Status)) {
  54     goto Failed;
  55   }
  56
  57   return Status;
  58
  59 Failed:
  60   ASSERT_EFI_ERROR (Status);
  61   CpuDeadLoop ();
  62   //
  63   // Keep compilers happy.
  64   //
  65   return Status;
  66 }