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   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/PcdLib.h>
  21 #include <Library/QemuFwCfgLib.h>
  22 #include <Library/UefiBootServicesTableLib.h>
  23
  24 EFI_STATUS
  25 EFIAPI
  26 PlatformHasAcpiDt (
  27   IN EFI_HANDLE       ImageHandle,
  28   IN EFI_SYSTEM_TABLE *SystemTable
  29   )
  30 {
  31   EFI_STATUS           Status;
  32   FIRMWARE_CONFIG_ITEM FwCfgItem;
  33   UINTN                FwCfgSize;
  34
  35   //
  36   // If we fail to install any of the necessary protocols below, the OS will be
  37   // unbootable anyway (due to lacking hardware description), so tolerate no
  38   // errors here.
  39   //
  40   if (MAX_UINTN == MAX_UINT64 &&
  41       !PcdGetBool (PcdForceNoAcpi) &&
  42       !EFI_ERROR (
  43          QemuFwCfgFindFile (
  44            "etc/table-loader",
  45            &FwCfgItem,
  46            &FwCfgSize
  47            )
  48          )) {
  49     //
  50     // Only make ACPI available on 64-bit systems, and only if QEMU generates
  51     // (a subset of) the ACPI tables.
  52     //
  53     Status = gBS->InstallProtocolInterface (
  54                     &ImageHandle,
  55                     &gEdkiiPlatformHasAcpiGuid,
  56                     EFI_NATIVE_INTERFACE,
  57                     NULL
  58                     );
  59     if (EFI_ERROR (Status)) {
  60       goto Failed;
  61     }
  62
  63     return Status;
  64   }
  65
  66   //
  67   // Expose the Device Tree otherwise.
  68   //
  69   Status = gBS->InstallProtocolInterface (
  70                   &ImageHandle,
  71                   &gEdkiiPlatformHasDeviceTreeGuid,
  72                   EFI_NATIVE_INTERFACE,
  73                   NULL
  74                   );
  75   if (EFI_ERROR (Status)) {
  76     goto Failed;
  77   }
  78
  79   return Status;
  80
  81 Failed:
  82   ASSERT_EFI_ERROR (Status);
  83   CpuDeadLoop ();
  84   //
  85   // Keep compilers happy.
  86   //
  87   return Status;
  88 }