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   This program and the accompanying materials are licensed and made available
   8   under the terms and conditions of the BSD License which accompanies this
   9   distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  13   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14 **/
  15
  16 #include <Guid/PlatformHasAcpi.h>
  17 #include <Guid/PlatformHasDeviceTree.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/DebugLib.h>
  20 #include <Library/UefiBootServicesTableLib.h>
  21
  22 EFI_STATUS
  23 EFIAPI
  24 XenPlatformHasAcpiDt (
  25   IN EFI_HANDLE       ImageHandle,
  26   IN EFI_SYSTEM_TABLE *SystemTable
  27   )
  28 {
  29   EFI_STATUS Status;
  30
  31   //
  32   // If we fail to install any of the necessary protocols below, the OS will be
  33   // unbootable anyway (due to lacking hardware description), so tolerate no
  34   // errors here.
  35   //
  36   // Always make ACPI available on 64-bit systems.
  37   //
  38   if (MAX_UINTN == MAX_UINT64) {
  39     Status = gBS->InstallProtocolInterface (
  40                     &ImageHandle,
  41                     &gEdkiiPlatformHasAcpiGuid,
  42                     EFI_NATIVE_INTERFACE,
  43                     NULL
  44                     );
  45     if (EFI_ERROR (Status)) {
  46       goto Failed;
  47     }
  48   }
  49
  50   //
  51   // Expose the Device Tree unconditionally.
  52   //
  53   Status = gBS->InstallProtocolInterface (
  54                   &ImageHandle,
  55                   &gEdkiiPlatformHasDeviceTreeGuid,
  56                   EFI_NATIVE_INTERFACE,
  57                   NULL
  58                   );
  59   if (EFI_ERROR (Status)) {
  60     goto Failed;
  61   }
  62
  63   return Status;
  64
  65 Failed:
  66   ASSERT_EFI_ERROR (Status);
  67   CpuDeadLoop ();
  68   //
  69   // Keep compilers happy.
  70   //
  71   return Status;
  72 }